Rear Brake Conversion Advice

[Doc76]

I have drums on the back of my Mk4 and want to convert to disc for obvious reasons.
Currently running mustang Cobra discs up front.
Had a chassis guy quote me ~$4k CAD to convert to 6 piston Wilwoods just on the back. Said he’d have to crop the 3-link axles to maintain width.

If I am going to convert the back, would it make sense to convert the front to Wilwood as well should I go that route?

Would you guys stick with the Cobra discs up front and convert the back to Mustang disc?
I know Wilwoods and Cobra discs are not really comparable but considering I’m already Cobra disc up front, just a thought.

Thanks in advance!

[Flip Smiley]

The first thing I would recommend is calling and speaking to Richard Oben at North Race Cars. He is the go to guy for drum to disc conversions for these cars. I think you can get this done for a lot less than 4K. North Race Cars is also a supporting sponsor for this site.
Best regards, Flip

[Jeff Kleiner]

Man, there are a lot of gougers out there who will try to take advantage of the uninformed… :(

Go with this:

https://www.factoryfiveparts.com/16285-performance-11-65-rear-brake-set/

Along with a 1994/1995 Mustang Cobra 15/16” bore master cylinder.

Jeff

[Higgybulin]

x2 what Jeff said. Factory Five could probably have those to you by next weekend! Bolt it up and go.
Higgy

[rich grsc]

You say you have rear drums? If so then you have an older 8.8 which is the CORRECT width, your so called mechanic has no clue to what he is doing, find someone honest

[Doc76]

Thanks guys
Kinda what I suspected on the gouger comments ;)
I have another, more trust worthy guy (cousin) I’ll be using in the future.
Will I have to swap any other components over or is it as simple as the kit swap?

Cheers

[Jeff Kleiner]

As I said, everything in the kit plus the 15/16” master. Does the car have power brakes? If not has the pedal modification been done?

Jeff

[Doc76]

Yes it has power brakes

Looks like this is the guy
https://www.cjponyparts.com/raybestos-brake-master-cylinder-power-disc-cobra-1994-1995/p/BMC22/

I see that the ‘93 stang has a 1”bore and is readily available in my area. Can I go bigger than 15/16” or is that not advisable?

[Norm B]

The master cylinder for a 93 is for disc / drum brakes and is not compatible with rear discs. The master cylinder you have a link to in post 8 is the correct one. The push rod out of the booster may need adjustment to work properly with the new master.
I think I am missing something, are your wheels 5 lug or 4?

Norm

[Jeff Kleiner]

Yes it has power brakes

Looks like this is the guy
https://www.cjponyparts.com/raybestos-brake-master-cylinder-power-disc-cobra-1994-1995/p/BMC22/

I see that the ‘93 stang has a 1”bore and is readily available in my area. Can I go bigger than 15/16” or is that not advisable?

No. Use the ‘94/‘95 master with 15/16” bore like I advised previously.

Jeff

[Doc76]

Ok thanks Jeff

[Doc76]

5 lug
Sorry for the confusion…..learner here ;)

[Doc76]

Jeff do you think I’ll need a proportioning valve?
I see some back and forth on this.

[Jeff Kleiner]

No.

Jeff

[Norm B]

Doc76, I would usually defer to Jeff’s advice on this but, I see you are in B.C. Canada. Hopefully someone from there will chime in with an answer to the proportioning valve. I have one mine that the proportioning part is gutted but, the isolation segment is still there. It is a required item for registering in some provinces. Was the car previously inspected and registered in B.C. and is there a valve on it now?

Norm

[Doc76]

Doc76, I would usually defer to Jeff’s advice on this but, I see you are in B.C. Canada. Hopefully someone from there will chime in with an answer to the proportioning valve. I have one mine that the proportioning part is gutted but, the isolation segment is still there. It is a required item for registering in some provinces. Was the car previously inspected and registered in B.C. and is there a valve on it now?

Norm

Hey Norm thanks for the feedback
Yes the car was inspected and regi’d in BC
No there’s no prop valve in there now. Stock mustang brake system. I read some owners experience rear brake lockup sometimes when doing this conversion and end up putting one of these valves in. Other guys, like Jeff suggested, don’t seem to need them. I am hoping I’m one of those guys unless it’s a “legal requirement”?

[rich grsc]

Hey Norm thanks for the feedback
Yes the car was inspected and regi’d in BC
No there’s no prop valve in there now. Stock mustang brake system. I read some owners experience rear brake lockup sometimes when doing this conversion and end up putting one of these valves in. Other guys, like Jeff suggested, don’t seem to need them. I am hoping I’m one of those guys unless it’s a “legal requirement”?
Don't know where you heard that, but the opposite of what happens. Almost everyone has issues trying to get MORE rear brakes not less.

[Jeff Kleiner]

You'll only have too much rear brake if the fronts aren't working properly or if the wrong master cylinder is used.

The easy button is the FFR kit. In addition you'll need the master cylinder we have already discussed and hub centric rings to center the rotors on the drum brake axle hubs:

https://lmr.com/item/SVE-4234HS/mustang-hub-centric-ring-79-93

Some brake line revisions will be necessary depending on how the original builder configured them, primarily at the back but possibly in the front as well depending upon how he addressed the drum master's 2 ports for the front circuit.

Jeff

[Norm B]

You said your car has stock Mustang brakes. Does your brake system have something that looks like this that the lines from the master cylinder go into before going out to the wheels?

Norm

[rich grsc]

You said this was a mrk4. Why is everything from years ago, are you sure that is what you have?

[Doc76]

It’s a Mk4. Builder obviously budgeted some stuff like the brakes, LCAs, stocker 302.
I saw this stuff and was prepared to have a swap a bunch of stuff.
The only way I was convincing my family of spending this kinda cash on a car was to able to drive it right away. Also my wife knows me enough to know if I built one she wouldn’t see me for hundreds of hours. ;)
This one fit my budget and time I have left.
Doesn’t take up too much room doing this stuff in the shop and my girls get to learn some mechanical skills while getting to ride in it right away. It was kinda strategic in several ways.
He spent quality time on things like the interior but cheaper out on the brakes, lower control arms were donor’d (have FFR arms sitting waiting for winter and my 16yr old will learn how to swap and what purpose they serve ;)

In hind sight would I still have bought the car? Yes
Am I thrilled about the choices he made? Nope…..

[Doc76]

You said your car has stock Mustang brakes. Does your brake system have something that looks like this that the lines from the master cylinder go into before going out to the wheels?

Norm

I actually do Norm.
Is that a prop valve?

[Norm B]

Yes and you want to gut it. You use the item in the link and remove all the items behind the similar looking plug on that device. https://lmr.com/item/M2450A/Mustang-Brake-Proportioning-Valve-Plug
It may have already have been done. Check before you get one.

Norm

[Doc76]

The builder went with the standard brake lines. It’s been suggested if I am going to the trouble to swap the rears to disc and upgrade the master, I may as well put better brake lines in like copper nickel or stainless steel.
I think I’ll do this because the builder didn’t do the prettiest job on the lines to begin with

Is there a go-to source for bulk rolls on brake line?

[J R Jones]

Doc, Norm B is on the right track but there may be confusion about the part in the picture and a proportioning valve.
Back in the day we raced a Shelby GT350 in SCCA BP and a Boss 302 in AS. BP rules then required the original drum brakes on the rear axle. The Shelby came with Norm's picture part AND a proportioning valve.
The proportioning valve can be hand adjusted to reduce/increase rear brake bias and balance brake system performance front to rear.

https://www.amazon.com/Wilwood-260-8419-Adjustable-Proportioning-Valve/dp/B002G37IEA/ref=asc_df_B002G37IEA/?tag=hyprod-20&linkCode=df0&hvadid=693521921711&hvpos=&hvnetw=g&hvrand=17033877734495392333&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9018934&hvtargid=pla-435957004991&psc=1&mcid=2f76d3b53fc7392f8e5a78f0d8f98495

The other valve is a check valve so that the rear wheel cylinders do not back-flow (brake released) into the master cylinder and make the rear brakes spongy. The check valve is not used on disc brakes because caliper pistons do not retract like wheel cylinders. The Boss 302 ran rear discs and eventually the GT350 ran rear discs in the GT ruled Trans Am. We had to remove the check valve with the disc brake update.
jim

[Doc76]

Doc, Norm B is on the right track but there may be confusion about the part in the picture and a proportioning valve.
Back in the day we raced a Shelby GT350 in SCCA BP and a Boss 302 in AS. BP rules then required the original drum brakes on the rear axle. The Shelby came with Norm's picture part AND a proportioning valve.
The proportioning valve can be hand adjusted to reduce/increase rear brake bias and balance brake system performance front to rear.

https://www.amazon.com/Wilwood-260-8419-Adjustable-Proportioning-Valve/dp/B002G37IEA/ref=asc_df_B002G37IEA/?tag=hyprod-20&linkCode=df0&hvadid=693521921711&hvpos=&hvnetw=g&hvrand=17033877734495392333&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9018934&hvtargid=pla-435957004991&psc=1&mcid=2f76d3b53fc7392f8e5a78f0d8f98495

The other valve is a check valve so that the rear wheel cylinders do not back-flow (brake released) into the master cylinder and make the rear brakes spongy. The check valve is not used on disc brakes because caliper pistons do not retract like wheel cylinders. The Boss 302 ran rear discs and eventually the GT350 ran rear discs in the GT ruled Trans Am. We had to remove the check valve with the disc brake update.
jim

So that I understand correctly are you saying the proportional valve is required?
I believe Jeff said it’s not needed in post #14

[J R Jones]

Jeff knows that combination of parts, I do not. I assume that he understands that it is a balanced system.
I have not been that lucky and my systems required tuning to optimize performance.
I would go with Jeff's advice and if your rear brakes require tuning, you can add a proportioning valve later.
jim

[Norm B]

Doc, my car has the brake system you are trying to build. No proportioning valve is needed. Car brakes on a dime and gives some change. The FFR roadster is really close to 50/50 front/rear weight distribution. The Fox body Mustang was about 60/40. This mod on a Fox body may have required a proportioning valve to prevent the rears from locking first. We do not.

Norm

[Doc76]

Doc, my car has the brake system you are trying to build. No proportioning valve is needed. Car brakes on a dime and gives some change. The FFR roadster is really close to 50/50 front/rear weight distribution. The Fox body Mustang was about 60/40. This mod on a Fox body may have required a proportioning valve to prevent the rears from locking first. We do not.

Norm

Thanks Norm
FFR conversion kit and a 1994/1995 Mustang Cobra 15/16” bore master cylinder it is!
Crazy that the rotors are $45 each and yet the kit is $699. (A couple caliper, 4 pads and a few brackets, nuts/bolts and cables somehow adds ~$600)
Now there’s the price of convenience I guess ;) lol

Thanks again guys

[Jeff Kleiner]

Thanks Norm
FFR conversion kit and a 1994/1995 Mustang Cobra 15/16” bore master cylinder it is!
Crazy that the rotors are $45 each and yet the kit is $699. (A couple caliper, 4 pads and a few brackets, nuts/bolts and cables somehow adds ~$600)
Now there’s the price of convenience I guess ;) lol

Thanks again guys

Well actually... I've used this package and there's a lot more to it than that. You're getting rotors, calipers, Stoptech performance pads, custom designed laser cut mounts (because there's no OEM application to use these rotors and calipers with a Fox width 8.8), stainless brake hoses and banjo bolts, parking brake cables and every single piece of necessary hardware. I didn't pay the list price but even if I had I feel that it's a good value. I guess if you don't think so you can go back to the guy who wants $4K. :rolleyes:

Jeff

[Doc76]

Well actually... I've used this package and there's a lot more to it than that. You're getting rotors, calipers, Stoptech performance pads, custom designed laser cut mounts (because there's no OEM application to use these rotors and calipers with a Fox width 8.8), stainless brake hoses and banjo bolts, parking brake cables and every single piece of necessary hardware. I didn't pay the list price but even if I had I feel that it's a good value. I guess if you don't think so you can go back to the guy who wants $4K. :rolleyes:

Jeff

lol nope it’s certainly convenient buying the kit!
BTW thanks again for the heads up on LMR and the hub centric rings. I see they also have the master in stock.
Cheers

[Norm B]

If you’re ordering from LMR, don’t forget about the plug I attached a link for in post 23.

Norm

[Doc76]

If you’re ordering from LMR, don’t forget about the plug I attached a link for in post 23.

Norm
Can I not just remove the prop valve all together given it’s not required?
Sorry if that sounds like a stupid question.

[Jeff Kleiner]

Can I not just remove the prop valve all together given it’s not required?
Sorry if that sounds like a stupid question.

Yes.

Jeff

[Doc76]

Yes.

Jeff

K thanks Jeff
And thanks again for the heads up on LMR as a source. There are no master cylinders across Canada to our spec so I’ll definitely be going the LMR route.
Same on the concentric spacers.
Cheers

[J R Jones]

Doc, I can not speak to that part specifically, it does not conform to the adjustable brake proportion devices I am familiar with. IF it is a drum brake specific part, I am concerned that it is the check valve I cautioned about previously.

A word on weight distribution, weight transfer and brake proportioning.
My application experience is racing cars where 1G plus braking is routine, lap after lap.
Consider the braking dynamic experienced with motorcycle racing and exhibition. It is called a "stoppie or stoppy" where the brake G force is so great the rear tire lifts off the pavement.
That illustrates weight transfer during braking. The harder the braking force, the more weight transfers from the rear to the front. If your braking style unloads the rear tires, a proportioning control becomes necessary.
jim

[Doc76]

In respect to the master cylinder. I like the LMR one because it maintains the opaque reservoir and is ~$150 cad vs something locally and aftermarket is $~400.
Can anyone tell me if the “rebuilt” LMR part number LRS-2140F will be a direct replacement master cylinder for this conversion?
It’s 15/16” bore is correct however it states push rod depth as being 1.40”.

Thanks

[Doc76]

Doc, I can not speak to that part specifically, it does not conform to the adjustable brake proportion devices I am familiar with. IF it is a drum brake specific part, I am concerned that it is the check valve I cautioned about previously.

A word on weight distribution, weight transfer and brake proportioning.
My application experience is racing cars where 1G plus braking is routine, lap after lap.
Consider the braking dynamic experienced with motorcycle racing and exhibition. It is called a "stoppie or stoppy" where the brake G force is so great the rear tire lifts off the pavement.
That illustrates weight transfer during braking. The harder the braking force, the more weight transfers from the rear to the front. If your braking style unloads the rear tires, a proportioning control becomes necessary.
jim

So I don’t want to be in a position having the car pulled apart and not having one. I’d rather have it and not need it than need it and not have it. Locally here, if I can even get it, these parts are stupidly priced.
For the few $ it’s worth should I get one of these coming from LMR with my master?
If so other than price, would you guys go for the Ford racing or Wilwood valve and why?

https://lmr.com/item/WIL-26010922/mustang-wilwood-adjustable-proportioning-valve-79-93

https://lmr.com/item/M2328C/Mustang-Ford-Racing-Adjustable-Brake-Proportioning-Valve

[J R Jones]

Doc, A lot of excess happens here and we are approaching the end of season. I feel Jeff has made a good point and you should follow his recommendation. There is nothing unsafe about that.
One (brake) test is worth a thousand opinions. Plumbing a proportioning valve is easily accomplished and you will have time for that iteration.
jim

[Doc76]

Doc, A lot of excess happens here and we are approaching the end of season. I feel Jeff has made a good point and you should follow his recommendation. There is nothing unsafe about that.
One (brake) test is worth a thousand opinions. Plumbing a proportioning valve is easily accomplished and you will have time for that iteration.
jim

Noted thanks Jim
Do you guys have a preferred source for copper-nickel brake line and know how much line it’ll take to re-plumb the car?

[Norm B]

Doc, the component that I recommended the plug for may be required in B.C. It is where I am. We get inspections every two years and won’t pass without it.
Check with someone local.

Norm

[Jeff Kleiner]

Noted thanks Jim
Do you guys have a preferred source for copper-nickel brake line and know how much line it’ll take to re-plumb the car?

I get pre-made/pre-flared sticks of various lengths from a local auto parts store (NAPA). I'm going to assume that you could do the same from Canadian parts retailers. Lengths will depend on routing. Join them as necessary with tees and couplers.

Jeff

[Doc76]

Anyone know the stroke requirement on the master cylinder when doing this swap?

[Doc76]

Yes.

Jeff

Jeff can you confirm that the Raybestos MC390217 will or will not work in this conversion?
I see a post from 2019 from you (at least I think its you) that indicates it won't unless I am misunderstanding.
I couldn't attach a pic so here is the link to the convo

https://thefactoryfiveforum.com/archive/index.php/t-31204.html

[Jeff Kleiner]

I don't know what part of that old conversation you're referring to that would make you believe that the Raybestos MC390217 wouldn't work. It's a 1994/1995 Mustang Cobra master cylinder with 15/16" bore...just like I have mentioned 3 times in earlier replies to this thread.

Jeff

[Doc76]

I don't know what part of that old conversation you're referring to that would make you believe that the Raybestos MC390217 wouldn't work. It's a 1994/1995 Mustang Cobra master cylinder with 15/16" bore...just like I have mentioned 3 times in earlier replies to this thread.

Jeff

I appreciate your time and replies Jeff.
Thanks

[Doc76]

Thanks for everyone’s help here helping me through the weeds, so to speak.
Ordered the kit from FFR this morning.
My 16yr old daughter and I will tackle this, this winter.
☺️

[Doc76]

Will I cause myself unforeseen issues by powdercoating the mount brackets from this FFR rear disc brake conversion kit?
(Ie, shimming issues, etc)

[Mbufford]

Maybe EdwardB chimes in at some point. But. When I had a rear brake issue, he pointed me to an EBay seller that provides Mustang GT takeoffs. They’re cost effective, bolt right on, and require zero mods.

[Doc76]

Maybe EdwardB chimes in at some point. But. When I had a rear brake issue, he pointed me to an EBay seller that provides Mustang GT takeoffs. They’re cost effective, bolt right on, and require zero mods.

Ya really curious to know if priming and Powdercoat on the brackets will cause any issue or what other guys have done in the past when converting

[Norm B]

I would drive fit all the parts before deciding on powder coating anything.
You have a lot of stuff to figure out before you can start assembly. I would have to check my Mustang manual but, I believe the axles have to come out to get the drum brake backing plate off. You are also converting to coil overs and need to consider how to mount the caliper brackets to avoid interference issues.
Read the assembly manual and get yourself a repair manual for the fox body and sn95 Mustang.

Norm

[Doc76]

I would drive fit all the parts before deciding on powder coating anything.
You have a lot of stuff to figure out before you can start assembly. I would have to check my Mustang manual but, I believe the axles have to come out to get the drum brake backing plate off. You are also converting to coil overs and need to consider how to mount the caliper brackets to avoid interference issues.
Read the assembly manual and get yourself a repair manual for the fox body and sn95 Mustang.

Norm

Ya I missed the fact that’s the axles have to come out. All the more reason to use my buddies hoist ;)
As for the conversion to coil-overs, I’m already on Koni’s on all four corners.

[Doc76]

203820

It’s funny that adding disc to the rear was skipped on this car

[rich grsc]

Spent $$$ on a differential cover, that should have been used on brakes. That cover has a 0 ROI. :rolleyes:

[JCB52]

Has anyone used this kit. Significantly less than FFR.
https://foxbodybrakes.com/products/1987-1993-5-lug-rear-brake-conversion-kit

[Jeff Kleiner]

Has anyone used this kit. Significantly less than FFR.
https://foxbodybrakes.com/products/1987-1993-5-lug-rear-brake-conversion-kit

That's the smaller 10.5" brakes; FFR's are the larger Cobra spec 11.65"

Jeff

[Norm B]

Can’t tell from the picture you posted. What size of wheels are on the car?
15 inch wheels limit the brakes that you can use,

Norm

[Doc76]

Can’t tell from the picture you posted. What size of wheels are on the car?
15 inch wheels limit the brakes that you can use,

Norm

Mine are 17”
I confirmed with FFR my wheel size and rear end width before purchasing their kit.
I went this route because some guys that seem knowledgeable here said it’s the easiest kit to install.

[Grubester]

Jeff: ...just to jump in on this thread -- I'm curious about the single master cylinder you recommend be used with the 11.65" rear brakes.
I have a new Mk 4 complete kit with IRS and the 11.65 rears, but FFR provides two brake masters and balance bar, etc.
I assume your 15/16" bore MC would apply to me, also, but how does the need to balance front/rear disappear? (If I'm reading you correctly)

(I was going to use a hand-held IR pyrometer to read front/rear disc temp after several medium effort stops using the temp metric as a balance indicator -- when I ever get to that stage.)

[CraigS]

I am pretty sure that the calipers are the same for 10.5 and the 11.65 brakes. Larger rotors and longer adapter brackets are the difference. The need to balance front to rear does not disappear. The FFR needs more rear brake than the Mustang parts will provide. If one doesn't have the balance adjustable dual MCs one way to help out is run more aggressive pads in the rear. Grubester, don't bother w/ temps. The only result that matters is whether front or rear wheels lock first so brake hard enough to find out. BTW, that test is best done at 35-40mph on a level road or parking lot.

[Norm B]

I will add “wet” to Craig’s list of test conditions above. In dry conditions the brakes may be balanced well enough to stop straight ahead but, with our weight distribution and staggered tire width, in wet conditions the back end can pass you faster than you can say WTF. (The F stands for Fudge��)

Norm

[Jeff Kleiner]

Jeff: ...just to jump in on this thread -- I'm curious about the single master cylinder you recommend be used with the 11.65" rear brakes.
I have a new Mk 4 complete kit with IRS and the 11.65 rears, but FFR provides two brake masters and balance bar, etc.
I assume your 15/16" bore MC would apply to me, also, but how does the need to balance front/rear disappear?


It doesn't. The reference to the 15/16" bore master cylinder is for a single, dual chamber master like the OP has on his car, not the dual master/balance bar setup.

Jeff

[Doc76]

Hey guys just wanted to take a second and say thanks again for all your help.
Very much appreciate all of you weighing in with past experiences and skills.

[Doc76]

Hey guys
So the only 15/16” MC I can find is from Mark at Breeze however this leaves the reservoir on top up under the fender. That’s what I have now and makes it a PITA to service.
I called Willwood and they only offer a 1” MC kit with remote reservoirs. (Pt# 261-14251-p or -bk)
They say this will work.
My question is what’s the impact to using the 1” vs the 15/16” cause Willwood said “it should work”.

[Mike.Bray]

Did you try Tilton? Too many issues with Wilwood anyway.

[Jeff Kleiner]

Once again, the 15/16” master is a dual chamber unit for a 1994/1995 Mustang Cobra. Wilwood sand Tiltons are single chamber and won’t work with your pedal box. I’ve purchased this MC from NAPA and found it available to order from other parts stores such as Autozone, O’Reilly, Advance, etc.

Jeff

[Norm B]

Here is a link to Rockauto for a 15/16 bore dual chamber. https://www.rockauto.com/en/moreinfo.php?pk=10961768&cc=1134188&pt=1836&jsn=565
Another link for the nipples to convert the master cylinder for remote reservoirs http://www.lsbilletworks.com/
I made my own adapters to convert the stock reservoir into a remote one and connect to the master cylinder. Allows for the required low brake fluid warning system where I live.

Norm

[Doc76]

Once again, the 15/16” master is a dual chamber unit for a 1994/1995 Mustang Cobra. Wilwood sand Tiltons are single chamber and won’t work with your pedal box. I’ve purchased this MC from NAPA and found it available to order from other parts stores such as Autozone, O’Reilly, Advance, etc.

Jeff

Thanks Jeff
As I mentioned I do have a Breeze OEM MC in 15/16” however this leaves the reservoir up under the fender. Nearly impossible to service. I’m looking for a remote reservoir alternative.

[Norm B]

Doc, you buy the master cylinder Jeff recommended, pull off the attached reservoir, install the fittings to convert the master for remote reservoir use. Use the appropriate tubing for brake fluid to connect the master cylinder to the reservoirs of your choice.
The fittings are available from multiple sources. Summit Racing or http://www.lsbilletworks.com/. Click the link. On the left hand side is a selection for FFR. Click master cylinder convert nipples. Order 2.

HTH

Norm

[Doc76]

Doc, you buy the master cylinder Jeff recommended, pull off the attached reservoir, install the fittings to convert the master for remote reservoir use. Use the appropriate tubing for brake fluid to connect the master cylinder to the reservoirs of your choice.
The fittings are available from multiple sources. Summit Racing or http://www.lsbilletworks.com/. Click the link. On the right hand side is a selection for FFR. Click master cylinder convert nipples. Order 2.

HTH

Norm
Thanks Norm!

[Doc76]

Can anyone recommend how to remove the reservoir from the OEM style MC? It appears to be pressed on?
My reservoir location is tucked way up under the fender. Not a fan.
205365
Also any recommendations on remote reservoir setups?
I do like the opaque OE look to be able to see the level without removing the cap.

[Doc76]

Doc, my car has the brake system you are trying to build. No proportioning valve is needed. Car brakes on a dime and gives some change. The FFR roadster is really close to 50/50 front/rear weight distribution. The Fox body Mustang was about 60/40. This mod on a Fox body may have required a proportioning valve to prevent the rears from locking first. We do not.

Norm

Are your calipers forward or rearward facing?
It appears there are mixed reviews how and why builders choose to mount the calipers forward or rearward facing?

[Jeff Kleiner]

It appears there are mixed reviews how and why builders choose to mount the calipers forward or rearward facing?

FWIW, I always move them to the front because it allows the parking brake cable to routed in a smoother "U" shaped curve rather than having to make an "S".

https://thefactoryfiveforum.com/attachment.php?attachmentid=205271&d=1728873455

Some have reported caliper to coilover interference with the caliper to the rear although I haven't seen it.

Regarding the reservoir; it is simply pushed on with it's nipples engaging the rubber grommets on the master cylinder and can be pried off (its a tight fit). I've done 5 or 6 cars using the vacuum booster and yes it pushed the master cylinder fill cap up under the fender however it can easily be twisted off. I didn't use remote reservoirs on any of them but instead just hit the "easy button" and made this for filling or adding fluid:

https://thefactoryfiveforum.com/attachment.php?attachmentid=205370&d=1729090319

:D

Jeff

[Doc76]

FWIW, I always move them to the front because it allows the parking brake cable to routed in a smoother "U" shaped curve rather than having to make an "S".

https://thefactoryfiveforum.com/attachment.php?attachmentid=205271&d=1728873455

Some have reported caliper to coilover interference with the caliper to the rear although I haven't seen it.

Regarding the reservoir; it is simply pushed on with it's nipples engaging the rubber grommets on the master cylinder and can be pried off (its a tight fit). I've done 5 or 6 cars using the vacuum booster and yes it pushed the master cylinder fill cap up under the fender however it can easily be twisted off. I didn't use remote reservoirs on any of them but instead just hit the "easy button" and made this for filling or adding fluid:

https://thefactoryfiveforum.com/attachment.php?attachmentid=205370&d=1729090319

:D

Jeff

Awesome thanks Jeff
I think I’ll leave it alone and not go the remote route either. I think it’s a cleaner look not seeing reservoirs ;)

Do you happen to know a good source for matching SS braided front brake lines for the ‘87-93 mustang disc?
I’ll be putting the rear disc FFR conversion kit in which came with nice SS flex lines however my front ones are rubber and fittings are corroded. Like to clean that up at the same time while I run new NiCo lines.

[Jeff Kleiner]

Awesome thanks Jeff
I think I’ll leave it alone and not go the remote route either. I think it’s a cleaner look not seeing reservoirs ;)

Do you happen to know a good source for matching SS braided front brake lines for the ‘87-93 mustang disc?
I’ll be putting the rear disc FFR conversion kit in which came with nice SS flex lines however my front ones are rubber and fittings are corroded. Like to clean that up at the same time while I run new NiCo lines.

Mark Reynolds at Breeze can set you up with hoses, banjo bolts, fittings and anything else you might need.

https://breezeautomotive.com/product-category/brakes/

Jeff

[rich grsc]

Guess Google search doesn't work up north.?

[Doc76]

Thanks Jeff
Spoke to Mark this morning. Very helpful. Ordered up.

[Doc76]

For those of you running the e-cable up and over the frame, did you have to shorten the cables?
I see pulley systems online fabricated to avoid driveshaft loops.
Mine presently runs down and under as the build book shows. I was under the impression the e-brake cables that came in the FFR rear disc conversation was shorter to accommodate the up and over setup however after speaking to FFR today it sounds like that is not the case. They still recommend the cables go down and under.

[Doc76]

FWIW, I always move them to the front because it allows the parking brake cable to routed in a smoother "U" shaped curve rather than having to make an "S".

https://thefactoryfiveforum.com/attachment.php?attachmentid=205271&d=1728873455

Some have reported caliper to coilover interference with the caliper to the rear although I haven't seen it.

Regarding the reservoir; it is simply pushed on with it's nipples engaging the rubber grommets on the master cylinder and can be pried off (its a tight fit). I've done 5 or 6 cars using the vacuum booster and yes it pushed the master cylinder fill cap up under the fender however it can easily be twisted off. I didn't use remote reservoirs on any of them but instead just hit the "easy button" and made this for filling or adding fluid:

https://thefactoryfiveforum.com/attachment.php?attachmentid=205370&d=1729090319

:D

Jeff

Are you able to comment how far the wheel will be pushed outward as a result of the conversion if any?

[Norm B]

Doc, are you changing the axles?. If not, any difference in width will be the difference between the drum and rotor axle flange face. Minimal if anything.

Norm

[Doc76]

Doc, are you changing the axles?. If not, any difference in width will be the difference between the drum and rotor axle flange face. Minimal if anything.

Norm
Thanks Norm
I presently have no plans to change the axles.
Sounds like it should work out but I’ll come back with an update after I’ve installed the kit.

[Doc76]

Hey guys just digging into this.
I was under the impression the adjustable Wilwood prop valve was plumbed into the rear line but in speaking to FFR they said to remove the OEM one (suggested here to gut and plug) and Wilwood adjustable valve actually gets plumbed into the front line.

Can anyone confirm that?

[Jeff Kleiner]

Hey guys just digging into this.
I was under the impression the adjustable Wilwood prop valve was plumbed into the rear line but in speaking to FFR they said to remove the OEM one (suggested here to gut and plug) and Wilwood adjustable valve actually gets plumbed into the front line.

Can anyone confirm that?

Well, since these cars almost always have too much front brake and not enough rear brake why would you want to put a prop valve in the rear to reduce the effectiveness even more...

Jeff

[Norm B]

Doc, the fox body V8 Mustang has a weight distribution of approximately 60/40 front/rear. Manufactures, for safety reasons, are always going to set their brake system to lock the front brakes before the rears in all conditions. The FFR roadster is very close to 50/50 weight distribution. Mustang brakes will always have too much front bias to achieve maximum stopping power when used on the roadster.
The question is, do you need maximum braking ability for how you intend to use the car? Are you going to be racing? Or, are you going to be driving friends and family around and want good, safe and reliable brakes?
If you mess around with brakes, without knowing exactly what you’re doing, you can create a very dangerous situation. Too much rear bias will cause the back end to come around and you will be looking back where you were coming from.


Norm

[GoDadGo]

Have you thought about possibly going with 1995 Ford Explorer Rear Brakes?
They use a Top Hat style brake rotor for the parking brake.
I've got them on my car and they work very well.
The diameter is just a bit over 11 inches.
I got my set up from Moser Engineering.

Check out Moser Engineering's OEM style rear brake systems shown below:

https://www.moserengineering.com/Parking-Brake-Kits.dept

[Doc76]

Front it is!

[Doc76]

Have you thought about possibly going with 1995 Ford Explorer Rear Brakes?
They use a Top Hat style brake rotor for the parking brake.
I've got them on my car and they work very well.
The diameter is just a bit over 11 inches.
I got my set up from Moser Engineering.

Check out Moser Engineering's OEM style rear brake systems shown below:

https://www.moserengineering.com/Parking-Brake-Kits.dept

Already have the rear FFR kit in the shop :)

[PG_Cobra]

Video from Master Power Brakes on brake combination valves: https://youtu.be/dD1dbNtH-6s

I have the MPB disc-disc combination valve installed.

[Doc76]

Video from Master Power Brakes on brake combination valves: https://youtu.be/dD1dbNtH-6s

I have the MPB disc-disc combination valve installed.

What’s interesting (and contributes to my confusion) with this video is this guy says to never install a prop valve in the front.

[PG_Cobra]

I have it installed with the prop valve to the rear brakes. According to MPB it only kicks in under severe braking to keep the rear end stable. It doesn't proportion the rear brakes at other times.
The function I really wanted was the safety shuttle so if I get a line failure I still have braking capability, somewhat reduced.

[Doc76]

I have it installed with the prop valve to the rear brakes. According to MPB it only kicks in under severe braking to keep the rear end stable. It doesn't proportion the rear brakes at other times.
The function I really wanted was the safety shuttle so if I get a line failure I still have braking capability, somewhat reduced.

Can you share a picture of the setup when able?

[PG_Cobra]

Picture attached

206163

I have removable panels for easy access. The MC is for a Chrysler New Yorker, 1"-ish (metric) bore with left hand ports. Just no room on a MK1 with booster to get the lines in on a Mustang MC with RH ports. Under floor exhaust so tons of room and no heat problems

[Doc76]

Doc, are you changing the axles?. If not, any difference in width will be the difference between the drum and rotor axle flange face. Minimal if anything.

Norm
I hadn’t planned but I wonder if this is a good time to upgrade to 31 spline while the rear is out and apart?

[Doc76]

Can I cut these brackets off to clean up the axles once pulled and welding or is there a chance they’re used for future mods?
Looks like the Moser axle doesn’t have them either.
206972206973

[Norm B]

Those brackets are for the quad shocks used with the Mustang 4 link suspension. You already have a 3 link setup so they can go.

Norm

[Doc76]

Took longer than I hoped but one last step to test fit the wheels to verify clearance and it’s all ready to strip.
That’s again to all those here that offered support
206976206977206974206975

Also, I see that my studs are now too short. Thank goodness I didn’t order axles yet. There a heavy 3/16” too short to the face of the nut.
Any recommendations on how long to lengthen them by without interfering with the trim ring?
206981206978206979206980

[Doc76]

Anyone have pictures they could share of how they routed the 20” SS rear brake line from the FFR conversion kit?
Seems the line is ~3” too long and the only way I can see they can work is to put a loop in the line. I get there need to be extra for axle drop. FFR said the lines used to be 17” but now they provide 20” front and rear.
206997

Is there anything else I should look for before yanking everything back off for rear end removal?

[Flip Smiley]

Hey Doc on your rear axle stud length. Are you sure all the surfaces are clean and pulled completely flush. The stock axle stud should have 1.34” available length. The stack up, brake rotor, wheel and lug nut is approximately 1.34” loose fit before torque applied. You may have something interfering with allowing for flush draw up?
Just a thought?
Best regards.

[Doc76]

Hey Doc on your rear axle stud length. Are you sure all the surfaces are clean and pulled completely flush. The stock axle stud should have 1.34” available length. The stack up, brake rotor, wheel and lug nut is approximately 1.34” loose fit before torque applied. You may have something interfering with allowing for flush draw up?
Just a thought?
Best regards.

Hey Flip
Thanks for the feedback.
I just checked, off the axle face my studs are 1.325” and the rotor is ~.324”. When I mount the rotor and hold it to the axle face I have .978”. When I measure the face of the nut sitting in the wheel, to the back of the wheel face I get 1.193”. So those checks verify the studs on these axles are now ~1/4” too short just to the face of the nut. Couple that with the fact the first ~1/4” of the stud has no thread, I think I need studs 1/2” longer on my new axles.
Any feedback is appreciated

207014

[Flip Smiley]

OK good check. I’m not an engineer and don’t play one on TV. Maybe others with more knowledge in this area can chime in. When torqued to spec if the end of the stud is flush with the face of the nut that may be enough thread engagement? I know the studs are tapered with no thread on the end.
Many others have put these exact parts together with the same results. If there is a problem many others have the same issue.
Best regards Flip

[Doc76]

lol we call them pretengineers in my line of work.

I did a bunch more reading this.
From what I can tell the 1987-1993 era mustangs and explorers had longer studs on the axles than Aerostars which were also pillaged for the 5 lug conversions on many mustangs.
Not sure if this is possible.
I’ll call FFR this week.

[David Williamson]

you need longer studs, Press the old ones out and pull new ones in. The threads on the lug nuts should be fully engaged with the threads on the studs.
David W

[Jeff Kleiner]

Pretty simple really. The FFR rims which you have use open ended lug nuts. If the threads don’t come all the way through the studs are too short.

Jeff

[Norm B]

Doc, recommend you press a stud out and take it with you to the parts store. I bought some online that I thought were correct but my Moser SN95 conversion axles had a bigger knurled section where they pressed into the axle flange than the regular SN95 ones.
Got 10 longer replacement ones at Costco. Saw they had a vast assortment of studs while I was there getting winter tires for another vehicle. Apparently they brake a lot of studs.��

Norm

[Doc76]

Do any of you guys know how far the stud can stick past the nut face before interfering with the decorative cap held on by the spinner?

[rich grsc]

Thread engagement at minimum is equal to the diameter of the stud. So a 1/2" stud needs 1/2" of threads. Look at a bolt & nut, the nuts are rarely taller than the diameter of the bolt.

[Jeff Kleiner]

Do any of you guys know how far the stud can stick past the nut face before interfering with the decorative cap held on by the spinner?

Here's one that I have in here currently with FFR rims along with their supplied lug nuts and wheel studs. It could go farther, but why would you? As long as there are threads beyond the end of the nut there's no need.

https://thefactoryfiveforum.com/attachment.php?attachmentid=207042&d=1733166432

Jeff

207042

[Doc76]

Here's one that I have in here currently with FFR rims along with their supplied lug nuts and wheel studs. It could go farther, but why would you? As long as there are threads beyond the end of the nut there's no need.

https://thefactoryfiveforum.com/attachment.php?attachmentid=207042&d=1733166432

Jeff

207042

Perfect!
Thanks so much Jeff.
Looks like there lots of wiggle room

[Doc76]

Anyone have pictures they could share of how they routed the 20” SS rear brake line from the FFR conversion kit?
Seems the line is ~3” too long and the only way I can see they can work is to put a loop in the line. I get there need to be extra for axle drop. FFR said the lines used to be 17” but now they provide 20” front and rear.
206997

Is there anything else I should look for before yanking everything back off for rear end removal?

Spoke to FFR today who said the 20” lines you just gotta kinda find a way to make them work so they don’t get hung up on anything. I plan to reassemble everything (axles are out now) to look at it again. If I install per the instructions, the lines are simply too long and look like they’ll rub on the tire. Rather than mounting the bracket vertically, facing out, I wonder if mounting it horizontally to promote the line dropping down is the way to go.
This is how Mark at Breeze suggested running the front lines to avoid a similar situation on the front 20” lines to avoid them rubbing when turning.

[Doc76]

Any good reason to not mount the rear brake line mounts behind the 3/4” tube instead of in front?
I had a hole on each side of the car on the inside of the 3/4” from the OB mounting straps so I thought I could plug the holes at the same time.
Also, the lines are no longer 17” and FFR’s kit comes with 20” lines front and rear so there’s a lot of excess line to take care of. I’m thinking it at least pushes the mount back 3/4”.
208335

[Doc76]

Has anyone mounted one of these Willwood adjustable proportional valves behind the drivers seat under the car so the black knob sits through the rear wall?
I was thinking it may be a good option to be able to reach it. (Ie just reaching around the seat with your right hand)
I am aware ill likely adjust it once and likely not again but I don't want to see it in the the cockpit, don't want to have the added complexity of the remote cable adjuster with big blue knob and mounting it in the engine bay is a little less "neat" looking IMO.
Seems to me if you have access to the underside of the car this would be a better option for reaching it on the fly and should a leak occur, its not dripping on/near headers, etc.
The only reason I can see this is not a good idea, and probably should be a big consideration, is the valve itself being much more exposed to the elements.
I am aware I may not need one but as good measure for the $50 I believe adding an adjustable valve now to be less work/time/$ than potentially later.

208662

[rich grsc]

NO adjustable proportional valve. You've been given this advice before, listen to it. If you have $50 buck to throw away, just send it to me

[Doc76]

Doc, recommend you press a stud out and take it with you to the parts store. I bought some online that I thought were correct but my Moser SN95 conversion axles had a bigger knurled section where they pressed into the axle flange than the regular SN95 ones.
Got 10 longer replacement ones at Costco. Saw they had a vast assortment of studs while I was there getting winter tires for another vehicle. Apparently they brake a lot of studs.��

Norm

My 31-spline Moser axles came with the correct length studs. Yes, I am referring to the axles I had no plans to change lol :) Funny I couldn't find them locally.

[Doc76]

Looking for a little reassurance here. Before I start flaring I have a tool that does 45deg flares.
I called and asked FFR to be sure and they said the brake line fittings in their rear brake kit are all SAE 37deg standard flares however from what I see online the standard for SAE is in fact 45deg.
It looks like the AN fittings are 37deg.
Can anyone confirm?

Thanks

[Jeff Kleiner]

45 degree double flare on the hard lines. The AN fittings on the flex hoses are 37 degrees.

Jeff

[Doc76]

Anyone able to confirm which booster is the correct fitment to clear the steering components?
I won’t have a chance until the weekend to pull the old one and I just opened the box and the invoice states they should have shipped the 1987-1993 Mustang booster but I notice on the line item it lists the new one as a ‘93 Cobra R booster, looks like compared to the one in the car this new one may be too big on the bottom of the body to clear. On other threads it looks like this will be an issue.
Just wondering if I have the wrong booster.

209207

I’m guessing I should have been shipped one of these below?
So next question is why is the first one more than half the price of the last two and all three are reman’d
209209
209210209211

[Jeff Kleiner]

It needs to be a regular Mustang booster, not Cobra. Has the car had power brakes previously or are you converting?

Jeff

[Norm B]

Doc, why are charging the booster. The one on the car is the correct one.

Norm

[Doc76]

It needs to be a regular Mustang booster, not Cobra. Has the car had power brakes previously or are you converting?

Jeff

Hey there Jeff
Yes the car had PB.
Looks like I have the wrong one :(
Thanks

[Doc76]

Doc, why are charging the booster. The one on the car is the correct one.

Norm
Morning Norm
The one in the car is 38 years old from a donor. Looking closely it’s been wire wheeled and repainted, my guess is several times by the look. Looking closely it has painted over rust all the way around the seam of the body and at the plunger. While I have the car apart, with my luck, I will get it back together and it’ll fail so makes sense, even for piece of mind, to replace it.
Once again it’s good that I have dove in this deep. The 3/4” tube that was coped around the booster, while the geometry is nicely done IMO, the welds are all cold lapped and have cracked as a result so I’ll have to get in there and fix it once I get the booster out.
I do like the Whitby mod assy however.

[Jeff Kleiner]

Morning Norm
The one in the car is 38 years old from a donor. Looking closely it’s been wire wheeled and repainted, my guess is several times by the look. Looking closely it has painted over rust all the way around the seam of the body and at the plunger. While I have the car apart, with my luck, I will get it back together and it’ll fail so makes sense, even for piece of mind, to replace it.
Once again it’s good that I have dove in this deep. The 3/4” tube that was coped around the booster, while the geometry is nicely done IMO, the welds are all cold lapped and have cracked as a result so I’ll have to get in there and fix it once I get the booster out.
I do like the Whitby mod assy however.

Actually the tubing mod looks OK; it's not a highly stressed tube. If you're inclined to change it it can be done much more simply by using a piece of 3/4" square tubing beside the existing tube to bridge the cut out portion. I bolt them in with key stock driven inside the tubes so that they don't crush but you could certainly weld it. Here's a couple of pics.

https://thefactoryfiveforum.com/attachment.php?attachmentid=209220&d=1737043150

https://thefactoryfiveforum.com/attachment.php?attachmentid=209221&d=1737043393

When you get into yours check to see if the booster is mounted directly up against the front wall of the footbox or if it is spaced forward away from it. The donor Mustangs have a double firewall so to keep the pedal and booster in the same relationship when used in our cars the booster had to be spaced forward off of the front wall approximately 3/8". If this isn't done it creates fitment issues and also the pedal will be high when at rest and may even contact the square tubing under the steering shaft. Mike Everson offers a machined spacer however I go cheap and easy by using flange nuts on the studs so that their flat faces rearward. I also use a piece of memory foam around the booster "snout" to seal off the hole.

https://thefactoryfiveforum.com/attachment.php?attachmentid=209222&d=1737043880

Cheers,
Jeff

[Doc76]

Actually the tubing mod looks OK; it's not a highly stressed tube. If you're inclined to change it it can be done much more simply by using a piece of 3/4" square tubing beside the existing tube to bridge the cut out portion. I bolt them in with key stock driven inside the tubes so that they don't crush but you could certainly weld it. Here's a couple of pics.

https://thefactoryfiveforum.com/attachment.php?attachmentid=209220&d=1737043150

https://thefactoryfiveforum.com/attachment.php?attachmentid=209221&d=1737043393

When you get into yours check to see if the booster is mounted directly up against the front wall of the footbox or if it is spaced forward away from it. The donor Mustangs have a double firewall so to keep the pedal and booster in the same relationship when used in our cars the booster had to be spaced forward off of the front wall approximately 3/8". If this isn't done it creates fitment issues and also the pedal will be high when at rest and may even contact the square tubing under the steering shaft. Mike Everson offers a machined spacer however I go cheap and easy by using flange nuts on the studs so that their flat faces rearward. I also use a piece of memory foam around the booster "snout" to seal off the hole.

https://thefactoryfiveforum.com/attachment.php?attachmentid=209222&d=1737043880

Cheers,
Jeff

Yes my booster is presently spaced out roughly the dim you mention. Thank you for the additional info. Perhaps I’ll just fix the welds, repaint and move on….
Correct booster is readily available locally which is a relief. Jeff do you paint the booster or is that a zinc coating of some sort?
Cheers

[Norm B]

Doc, my booster came the colour in Jeff’s picture and rusted instantly when I moved to Nova Scotia. That is one of my projects on the to do list before spring driving season starts.
The booster is crimped together and, as long as the crimps aren’t rusted out, you should be okay. You could always test it to see if the diaphragm is good and holds vacuum before reassembling everything.

Norm

[Doc76]

Doc, my booster came the colour in Jeff’s picture and rusted instantly when I moved to Nova Scotia. That is one of my projects on the to do list before spring driving season starts.
The booster is crimped together and, as long as the crimps aren’t rusted out, you should be okay. You could always test it to see if the diaphragm is good and holds vacuum before reassembling everything.

Norm
Interesting. If it’s Cardone which most seem to be, they claim to be rust resistant coated. Having said that given your proximity to the ocean, that’s a game changer. I recently sold a waterfront home in Tofino on Vancouver island. If it wasn’t 316ss, I was forever rust inhibiting and/or painting things.
Crazy how harsh the ocean air was on everything.

Funny I picked the correct one up today from local auto parts. Nicely painted black with gold zinc plated studs front and back. Too bad for us expectations of what we will receive from Cardone isn’t more predictable

[Doc76]

The new Cardone booster has a rubber collar that fits a rubber boot however with the collar on the booster, it doesn’t fit through the firewall. There isn’t anything in the build book regarding this.
The old one did not have this collar or boot however I do not want to assume the OB did those correctly.
This results in the need to enlarge the firewall hole by ~.200”
Do I cut the rubber collar off and turf the boot or enlarge the hole in the firewall?

209310209308209309

[Norm B]

I enlarged the hole. Made a guide, with the existing hole centre marked, out of a piece of plywood and used the booster mounting holes to bolt it to the front of the foot box. Then used an appropriate size hole saw to cut a hole through the plywood and the foot box front.

Norm

[Doc76]

I enlarged the hole. Made a guide, with the existing hole centre marked, out of a piece of plywood and used the booster mounting holes to bolt it to the front of the foot box. Then used an appropriate size hole saw to cut a hole through the plywood and the foot box front.

Norm

Thanks for the info Norm :)
Appreciate it.

[Doc76]

I enlarged the hole. Made a guide, with the existing hole centre marked, out of a piece of plywood and used the booster mounting holes to bolt it to the front of the foot box. Then used an appropriate size hole saw to cut a hole through the plywood and the foot box front.

Norm
Did you use a gasket or anything for sealing/vibration dampening or just booster on the wall?

[Norm B]

There is a spacer between the booster and the foot box front but, no gasket. I cut the hole in the spacer I made so that the rubber boot over the booster sealed against it.

Norm

[Doc76]

Sorry in advance for the less-than-clear image.
Hoping someone might chime in if this looks kosher?
I can’t confirm with any witness marking inside the flared brass fitting that this FFR supplied brass fitting is actually seating on the inverted flare between the brass and steel fittings that came in the rear FFR conversion kit. It really looks like it’s seating on the shoulder just near the end of the male threads.
I sent this picture to FFR tech support who suggested it looks fine. I’m just used to seeing a thread or two left over with these types of connections.
Short of filling and bleeding the line to see if it leaks, anyone have experience with these fittings from this kit and if so is this a normal fitup?
209654

[Nigel Allen]

Does not look promising. You could pressurize with compressed air, then do a leak test at the joint using soapy liquid.

[Doc76]

Yup the kit fittings leaked upon p-testing them. Ran to the local auto parts store and grabbed another one. Fixed the issue.
The FFR brass fitting I don’t believe was even close to seating. Note how much shorter the fitting on the left was from the kit.
Kit was also missing the banjo bolts and washers.

209687209688209689

[Doc76]

Anyone happen to know if there is a compatible rotor dust shield for the FFR Rear Disc Conversion Kit?
Kit didn’t come with any and I would like to install them.

[Norm B]

Doc, if you got the conversion axles that maintain the 87-93 rear end width then, I don’t believe there’s a dust shield available. The offset in the calliper mounting bracket shows you how far inward these axles move the brake rotors.
I know for certain the stock dust shield for a 95 Mustang does not work. Have been running around for 10 years without any and don’t miss them at all.

Norm

[Doc76]

What is allowable runout on the Mk4 rear discs before a guy should expect vibrations?
I ask because the Moser Axle they sent as a replacement to a manufacturing defect at Christmas, has a runout of .0035” on the axle face which is equating to ~.007” on the 11.65” rear disc rotor..
I noticed this when turning the rotor by hand and the “dragging” noise on one side was inconsistent.
I did try re-clocking the rotor in all 5 lug positions which did nothing. I also swapped rotors each side while measure their runouts as well.
It’s in the axles face.
Placed a dial indicator on the axle bearing surface which showed it’s running true and the discrepancy is in the axle face.
Studs were “pulled” into place with a wrench, hardened washers and nut. Didn’t use an impact, press or hammer. I know it’s not from that process.

[Doc76]

Am I missing something here or am I missing more parts from this kit?
Should the caliper end not have clips as well to retain the cable?

209908209909

[rich grsc]

No clip

[Jeff Kleiner]

You can use an “E” clip on the caliper end if you like but it isn’t necessary.

Jeff

[Doc76]

Sure a lot of issues seem guys run into routing the e-brake lines. I tried behind the shock which left them too short. I had to settle on slipping them between the shock and shock mount. On the passenger side I ran it through the banana bracket.
Is this kosher?
I can’t see a better way.
Any feedback is appreciated

210020210021210022

[Doc76]

Thanks again to all those that provided feedback on my conversion.
I like to hear how one’s project turned out so I thought I’d do a followup here.
Just got the car back from the chassis shop. They’re the local go-to guys for race/street car setups.
Set the weights, alignment, check driveline angles, pressure tested the brake system (one leak on the whole system detected and corrected), etc. pretty proud of that having never flared a line before and I replumbed the whole car myself :) The Nicop is the way to go.
Also did a driving temp test on the brakes. Under all conditions the rear brakes were consistently ~20 degrees cooler than the front. As suggested here, they also suggested no bias adjuster was needed.
They were very impressed with how well the brake system performs.
For topping up the system I use a large transfer syringe (Amazon). I did end up fabricating an access panel on the inner wheel well panel to make accessing my MC easier. So much easier for topping it off.
Bolted with rivnuts.
213249213252213251
Thank you kindly again to all those that provided guidance……on to an engine swap ;)

[Doc76]

I seem to have a “moan” or harmonic vibration coming from the rear brakes whether cold or hot. Mechanic and a couple knowledgeable guys here on the forum suggested this could be part of the pad bedding process.
I am fairly confident booster is adjusted correctly. I also did a brake temp check and fronts always run slightly hotter than rears. I have also confirmed the calipers are centered on the rotor correctly.
I do recall when installing the pads into the calipers they were very difficult to get into the caliper. Should the pads “float” freely in the caliper?
Just wanted to eliminate this if this is possibly the cause.
As a refreshers this was the FFR rear disc conversion kit with the 11.65” rotors.

[CraigS]

Back in the day there were 'anti-moan brackets' for this exact problem. Go to post #10 in this thread.
https://www.ffcars.com/threads/anti-moan-brackets-required.500785/
I don't know if this is still appropriate for the current setup or not. Hopefully others w/ more experience on the newest MkIVs will advise.
RE; pads difficult to get into the caliper. Do these calipers require that the piston be rotated to retract it.

[Doc76]

Back in the day there were 'anti-moan brackets' for this exact problem. Go to post #10 in this thread.
https://www.ffcars.com/threads/anti-moan-brackets-required.500785/
I don't know if this is still appropriate for the current setup or not. Hopefully others w/ more experience on the newest MkIVs will advise.
RE; pads difficult to get into the caliper. Do these calipers require that the piston be rotated to retract it.

Hello Craig
Thanks for the note on the anti moan brackets. I did see a little on that just not in the Mk4 application.
Not sure on the rotating piston but I’ll reach out to FFR tomorrow on that. Thanks for the suggestions

[Norm B]

I have anti moan brackets mounted on my rear brakes. Here’s a link to an old thread. Jeff’s post (#6) has a very good picture of the brake calliper and mounting bracket with the anti moan bracket installed. https://thefactoryfiveforum.com/showthread.php?50001-Are-my-Rear-Brakes-Mounted-on-th-Wrong-side&highlight=Anti+moan+bracket

Norm

[Doc76]

I have anti moan brackets mounted on my rear brakes. Here’s a link to an old thread. Jeff’s post (#6) has a very good picture of the brake calliper and mounting bracket with the anti moan bracket installed. https://thefactoryfiveforum.com/showthread.php?50001-Are-my-Rear-Brakes-Mounted-on-th-Wrong-side&highlight=Anti+moan+bracket

Norm
Thanks Norm
Should the pads float in the calipers?
The pads that came with the FFR kit were extremely difficult to install into the calipers.

[Norm B]

If I remember correctly, the pads fit fairly tight. The guide pins provide the required ability for movement that allows the brakes to work properly.

[Doc76]

If I remember correctly, the pads fit fairly tight. The guide pins provide the required ability for movement that allows the brakes to work properly.
Ok thanks again Norm
As some suggested perhaps I need to allow more time for pad bedding. (Only had ~20 miles on the new setup)
I’d never heard of pad bedding before having this car.

[Sully!]

Doc;
Follow Jeff Kleiner's advice. It's as good as calling FF5 support folks.
Kevin

[Doc76]

Doc;
Follow Jeff Kleiner's advice. It's as good as calling FF5 support folks.
Kevin

You bet. I’d actually argue Jeffs advice has, for me anyways, been more effective.
Once I resolve this pad bedding, moan issue, this conversion will be wrapped up.
Cheers