Brake booster question

[Mookie10]

I just purchased a mkIV that has manual brakes and manual steering. I would like to add a brake booster, do I use a mustang booster? Also the brake line to the right front brake line has a leak, I believe it is at the line/hose connection. Are the brake lines bent by the builder or are there pre-bent lines?

[DaleG]

If the builder used the kit-supplied lines, he bent them himself.

One of our vendors offers this brake kit: http://www.whitbymotorsports.com/UInvDetail.asp?s_keyword=brakes&s_cat=&inventoryid=1608

Same vendor offers pre-bent brake lines, but if you need a replacement section, just get it from an auto parts store and bend it yourself.

By the way, WELCOME. You will get all the help you need here and on the other forum. Where are you?

[Mookie10]

Thanks for the help...absolutely love the car. I am in Wisconsin, 15 minutes from Road America.

[edwardb]

Since it's a Mk4, very good chance it has a Wilwood pedal box. When you look at the front of the driver's footbox under the hood, can you see a master cylinder? If not, maybe you can see the cylinders inside the pedal box along with the Wilwood name on your brake and clutch pedal arms. If so, you have a Wilwood pedal box and adding power brakes is not simple on a completed car. It means moving the master cylinders from inside the footbox to outside, major changes to plumbing, and then a modification to the Wilwood box to allow either vacuum or hydroboost power brakes. Bottom line, I wouldn't recommend it for a completed car.

I'm also assuming since it's a newer build, it's probably 4-wheel disks. What is the problem with the brakes that you're trying to solve? Different pads can change things. I know it's worst case, but replacing the brakes entirely is an option and maybe easier than adding power. But that would be a last resort and would need more information to make a better recommendation.

As far as the brake lines, yes as stated likely they were bent and installed by the builder. Pretty generic and commonly used parts there. Should be an easy fix. Even if you have to re-do or replace stuff.

[DaleG]

As edwardb noted, installing booster on a finished car will be difficult; likely will have to remove the body and a few aluminum panels at top and side of driver's footbox.... not a bad winter project. As he also said, experimenting with different brake pads may yield the results you are looking for; plenty of threads here on brake pad selection.

[Mookie10]

The car is actually a mk3 and here's a pic of the master.46825

[edwardb]

The car is actually a mk3 and here's a pic of the master.46825

With the master cylinder outside the pedal box, adding power brakes is a little more doable. To your first question, can you add a Mustang booster? No, generally they're a little too big. But there are smaller vacuum boosters that do fit. The Whitby unit mentioned previously is an option. I seem to recall it uses a Mercury Villager booster, but I'm not positive. It does require a frame mod to fit though, and while possible with body on, it's probably more doable with the body off. So still not an easy proposition.

Two other things. First, you haven't described exactly what the problem is. What are you trying to accomplish with your brakes? Second, I don't think that's a Mk3. With the steering shaft out the side of the footbox like that, it's likely not newer than a Mk2. Do you know what brakes it actually has? There's a chance it has rear drum brakes.

[Jeff Kleiner]

...I don't think that's a Mk3. With the steering shaft out the side of the footbox like that, it's likely not newer than a Mk2.

Correct, that pegs it as a Mk1 or Mk2.

I'd be willing to wager that your high pedal effort and poor brake performance are because the original builder failed to do the brake pedal modification to correct the leverage after deleting the booster.

Jeff

[CraigS]

I noticed in your picture that you have the dreaded SS braided throttle cable. I recommend you switch to the plain black cable from Lokar.
Either this
http://www.summitracing.com/parts/lok-tc-1000u36/overview/
or this
http://www.summitracing.com/parts/lok-tc1000u48/overview/

[Mookie10]

There isn't any major problem with the brakes and it does have 4 wheel discs. The car just takes some effort to stop, my wife drives the car also and power brakes make it easier for her to get it stopped. I did some more digging and found the original order and the car is a mkII, purchased in 2001. All that being said, I am just curious how difficult it would be to add power brake to get the car to brake more like a modern vehicle. I appreciate all the input to this point

[Mookie10]

Correct, that pegs it as a Mk1 or Mk2.

I'd be willing to wager that your high pedal effort and poor brake performance are because the original builder failed to do the brake pedal modification to correct the leverage after deleting the booster.

Jeff

Is there somewhere that explains the pedal modification you mentioned so I can see if it has been done?

[Jeff Kleiner]

Although it won't be a walk in the park it can be done with the body on by working through the LF wheelwell with the tire off and the splash panel removed. You'll need to cut the 3/4" square frame member and open up the hole in the footbox front bulkhead. Brake lines will need to be reconfigured and the splash panel will have to be cut for master cylinder clearance. Assuming that the brake pedal was modified (which as I suggested above should be checked because if it wasn't it may be the root cause of the high pedal effort) it will need to be changed back to the original power brake configuration which is doable but challenging on a completed car, especially without a removeable footbox top.

Jeff

[Mookie10]

Although it won't be a walk in the park it can be done with the body on by working through the LF wheelwell with the tire off and the splash panel removed. You'll need to cut the 3/4" square frame member and open up the hole in the footbox front bulkhead. Brake lines will need to be reconfigured and the splash panel will have to be cut for master cylinder clearance. Assuming that the brake pedal was modified (which as I suggested above should be checked because if it wasn't it may be the root cause of the high pedal effort) it will need to be changed back to the original power brake configuration which is doable but challenging on a completed car, especially without a removeable footbox top.

Jeff

Thanks Jeff ,
I am guessing you are probably correct about the pedal modification. How would I check that? I would like to start there and see what improvement that makes

[Jeff Kleiner]

Is there somewhere that explains the pedal modification you mentioned so I can see if it has been done?

Here are some discussions:

http://www.ffcars.com/forums/17-factory-five-roadsters/205702-brake-pedal-mod-mkii.html

http://www.ffcars.com/forums/17-factory-five-roadsters/397290-brake-pedal-mod-question.html

http://www.ffcars.com/forums/40-2003-roadster-archives-read-only/83693-brake-pedal-mod.html

Mike Everson (Forum Vendor "Mikes Replica Parts") offers a pedal exchange:

http://www.replicaparts.com/brake%20pedal%20mod.htm

Good luck,
Jeff

[michael everson]

If your pedal box is from a 87-93 which I bet it is, look up where the brake pedal pivots. Does it pivot all the way up to the top of the pedal box or about 1.5 inches down? If all the way up, the pedal has not been modified. If 1.5 inches down then it had been modified. There are 2 sets of holes that the pedal can be mounted in. If the mod has been done and you want to do power brakes, you will need to change the pedal to an unmodified one. Otherwise the brakes will be very touchy and you will likely have too much pedal travel.
Mike

[Mookie10]

The pivot is at the top of the box. 4690846908. So would my best bet be to get the modified pedal?

[michael everson]

It would be a good start unless you plan on power brakes. You can get your pedal modified here.

www.replicaparts.com

Mike

[CraigS]

I have long advocated manual brakes but they take some work to get right. Since your wife is going to be driving, I am thinking that it might be best for you to go w/ a vac booster system. Right away, the effort becomes reasonable and easily managed by her. Then you can deal w/ other issues such as front to rear balance to optimize the system.

[Mookie10]

My next question, is the Whitby kit truly a bolt in kit or are there other mods that need to be done? I am thinking I should start with the pedal mod and see what that does and if I want to go with power later the Whitby kit comes with a pedal. I was also thinking of switching to steel braided brake hoses and getting new pads. Thoughts or recommendations on pads?? Thanks to all for the advice, much appreciated.

Peter

[michael everson]

The Whitby kit does not come with a new brake pedal. Not for the stock pedal box anyway. Pretty sure the older kits require you to open up the hole in the front of the foot box in order for the booster to fit. Also you will need to do the frame mod which comes with the kit. All of this is doable with the body on, but a real pain. If you decide to go with non power brakes, the removal of the power brake pedal will try your patience for sure.

Mike

[CraigS]

If you want to do the pedal mod and stay manual brakes, remove the driver seat. You will be laying on your back in the footwell a long time. If you stay manual I recommend Hawk HPS pads up front and Hawk HP+ pads in the rear. The HP+ dust a bunch but really add grip.