Front Brake Swap on an MK1

[maginter]

Hi All –

I had asked this before, but have not been able to find my notes and links from before.

So, I have an MK1, that I had considered adding big brakes to the from while doing a rear disc brake conversion. As happens with all of us, a single project turns into a continuing project. In adding rear disc, I am adding Power Brakes, and Power Steering, and receiving misc. parts containing a set of FFR MK3 Front Disc Brake. I have decided that I might as well swap out the front brakes as well.

I would be going form a 1993 Donor front end that already has a 5 lug conversion done. So, my question is, what else do I need to change out to make this work and what parts should I use. I believe I need to swap the Spindles and Hubs, so is that to go to the SN95 or later Spindle with the dog leg? Also, I thought I saw that the K Member needed to be changed out? In going to Power Steering, I assume that I would need to use a different Power Rack, from what would be used for the MK1 build originally???

Again, sorry for asking again, but I want to make sure it is correct.

TIA,

Mark

[Jeff Kleiner]

Hey Mark,

By "Mk3 front disc brake" I assume that you mean either the 1994-1998 Mustang single piston calipers or the 1999 up dual piston PBR calipers. Neither are exclusive to the Mk3. In either case, yes you'll need to use SN95 spindles and hubs and as you seem to already be aware the 1994-1995 spindles with the dogleg are preferred over the straight arm '96 and later versions.. The SN95 spindles require different positioning on the FFR spindle adapters than the Fox ones. Check yours---on the Mk2 and later cars the adapters had two sets of holes (4 holes total) but your Mk1 set is probably set up with one set of holes for Fox only. If you need the adapters that will accommodate the SN95 they usually aren't too hard to dig up here on the forum (pretty sure I don't have any but I'll check). Regarding the rack; it will use a Fox Mustang power rack. What's in the car now? An actual manual rack or a depowered power one? Mk1 might still have the old rag joint coupling which you'll want to do away with. If it has an actual splined coupling to a depowered power rack you'll already be good to go but if it's a spline into a manual rack you'll need to change it out because power and manual are different. Feel free to give me a call if you want to discuss it sometime.

Jeff

[maginter]

Thanks Jeff -

As for the front brakes, I will pull them and look, and sorry for not being more clear. There are the FFR front disc brakes shipped with the FFR Kit. These happen to be from an MK3 build, but like you said, not specific to the build. The steering rack that is in there is a depowered Power rack. I will need to check to see if I need the spindle adaptors. What do the adapters look like?

[maginter]

Hey Jeff -

I finally dug out everything I have. So the Brakes are the FFR front 2 piston 11 inch disc that comes with the FFR Vehicle build kit. I have the 1994-1995 SN95 Spindles, with the dog leg bend. As stated above the Rack is a depowered power rack form the donor vehicle. I am not sure what the adaptor looks like so here is a picture of the spindle from the front of the car.

Let me know what else I might need to finish this conversion out.

Thanks!

Mark

[Jeff Kleiner]

Hey Jeff -

I finally dug out everything I have. So the Brakes are the FFR front 2 piston 11 inch disc that comes with the FFR Vehicle build kit. I have the 1994-1995 SN95 Spindles, with the dog leg bend. As stated above the Rack is a depowered power rack form the donor vehicle. I am not sure what the adaptor looks like so here is a picture of the spindle from the front of the car.

Let me know what else I might need to finish this conversion out.

Thanks!

Mark

Oh man Mark, you're heading down a slippery slope here...

First of all this is the spindle adapter:

https://thefactoryfiveforum.com/attachment.php?attachmentid=214156&d=1747873886

What you have is the early Mk1 version that will only work with Fox Mustang spindles. The adapter that will accommodate SN95 spindles has 4 holes rather than 2.

https://cdn11.bigcommerce.com/s-6661c/images/stencil/1000x1000/products/147/387/ifsbracket__19059.1337868162.jpg?c=2

You would need this to use the 1994-1995 spindles.

Now, here's where the slippery slope comes in; I see that the car still has the tubular upper control arms (with a missing ball joint grease boot by the way) which attach in slots. These are difficult to keep in alignment and also do not allow enough adjustment to optimize the planned power steering. I suggest that you retrofit the adjustable upper arms like have been used ever since the Mk2. Next are the donor Mustang lower control arms; although there is not anything inherently wrong with them aside from weight (and in some peoples view their appearance) they don't play nice with SN95 spindles which results in a conflict with the tie rods coming into contact with them when the wheels are turned. Again, the solution is to replace them with Factory Five's current tubular lower control arms.

Long story short what may seem like a simple brake upgrade will likely snowball into a complete front suspension rework. Feel free to get in touch offline if you'd like to discuss.

Jeff





214156

[CraigS]

You can get needed wheel clearance by doing a little grinding.
214167
You can power up your existing rack but I'd do it where you can catch the leaks that it will probably have. So plan on a new rack at some point. There was a time that someone made inserts to fill in the slots in the frame when switching to newer style UCAs. When I did mine I bought some 1/8"x1.5" steel flat bar. Cut about a 2" piece and drilled a hole to make an oversized washer and welded it on top of the slots.

[maginter]

Hey Craig -

I had already made plans to swap the rack. They are relatively inexpensive and will not be contaminated from the donor.

Thanks for your input!!

Mark

[maginter]

Thank you Jeff -

I somewhat assumed that was the adaptor, but didn't know. To be clear I knew this would be a can of worms and not a simple brake swap. From what I remember reading before, but since I am doing all that I plan to this car, now is the time. I'll get with you off line to find out what the part swap inventory will be for what I need to do this. Let the adventure begin!!!

[CraigS]

When you go to buy a rack take a pair of vice grips w/ you. Clamp them gently onto the rack input shaft splines. Turn it all the way one way. note the vice grips position. now turn it all the way the opposite way. Be sure it goes three full turns. If it only goes 2.5 ask them to find another one. Unfortunately the rebuilders don't track this detail so you can get the wrong rack.