Donor Disassembly Question - Brakes

[azbruin]

Well, I went out and found an '88 mustang with a recently rebuilt engine (I may have it rebuilt again to get the HP boost FF recommends). I've started the demo and run into my first issue. The manual says there are four bolts holding the power assist unit to the firewall. I can see nothing on the engine side and perhaps two on the inside. Are there 4? Can one get at them this early stage in the tear down.

[Ray]

Yep there are four of those bolts. Not easy to get to but much easier with the steering column out of the way. You wouldn't happen to know anyone who use to be with Cirque du Soleil that could stop by and give you a hand?

Just skip past that part and continue with the tear down. Come back to it when you've created some room to access the part.

Ray

[azbruin]

No and just getting in there to look has put several new kinks in my 6'3" 61 year old frame. I have managed to tear out the dash and have disconnected almost all the wiring so It is looking easier. Had the same thought on getting the steering out of the way. Two more brake questions. I disconnected the switch. Do I cut the wires? The instructions on the master cyninder / distrib. block aren't clear to me. It says leave the lines from the block to the m.c. I can see no way to take off the block. It seems riveted on. If the block stays, do the lines stay with car or the m.c. ?

[Ray]

It's been about 10-years since I took my donor apart so I may be off on a few things. The bolts holding the power booster on are welded to the booster. They stick through the firewall and there are nuts holding it on. If you have to cut wires, leave them as long as possible, just in case you need to splice them back into the harness.

I'm looking at my build manual and it says to leave the brake lines attached to the mc and to cut the line about 4" from the distribution block. Make sure to use tape to mark the lines so you know which lines go to what. If the block is riveted to the car, you can drill the rivet out to remove it from the car.

If you really get stuck, I'm about 5 hours west of you and would be happy to drive out an help.

I've sent you a Private Message with my phone number if you need to give me a call.

Ray

[jakester888]

I am smiling now... as I just finished my tear down. I remember what a pain that brake booster was to get out. You have to contort yourself like a pretzel to get inside the footbox area way up under the dash to take them out.

I agree with Ray, get the steering column out of the way first if you can. I wrote an entry on this very topic... find it here:

http://thefactoryfiveforum.com/showthread.php?2577-Donor-teardown-question-Brake-booster-removal-are-you-kidding-me

Have fun.

[Ray]

Oh, take the seats out. Makes it much easier to lay on your back or side to contort yourself to reach those nuts.

Ray

[azbruin]

Thanks Ray, Jake,. I actually removed all of the dash so access got much easier. Turned out that the four bolts also held the pedal box on so once I found them, everything came apart nicely. A 10" socket extension cleared all the space. I also found that the distribution block was attached by a bolt into the wheel well so everything is off. I now have 15 years of caked crud to remove but that should be a piece of cake.

[Joe]

I'm telling you right now, do yourself a favor and take that brake booster to the auto parts store and use it as a core for a new one. A new one is only $72.00 and the one you have is basically an antique! You don't want to have to replace that brake booster once it's in your completed car. As me how I know!!!!! I'm still paying a chiropractor to get the kinks out of my back :) . My old brake booster sprung a leak a matter of days before I was scheduled to leave on a month long trip in the Roadster last summer.

http://www.ffcars.com/forums/17-factory-five-roadsters/272726-agggh-brake-booster-problem.html

[azbruin]

Thanks for the advice. Definitely don't want to have to repeat the process!!!

[Gale K]

Make sure you keep all brake line fittings associated with the distribution block and the master cylinder. Cut the brake line after it leaves the distribution block. I made the mistake of leaving the lower fitting(s?) on the donor, it left with the donor carcass, and I had to go fishing for another fitting. They are not a 'regular' auto parts part. You can get dozens from pick-n-pull, etc, but if you have it in your hands now, don't let it get away!

EDIT: Thinking back on it now, I believe there are a couple of fittings on the lower side.

Bottom line, SAVE ALL FITTINGS FROM MASTER CYLINDER, DISTRIBUTION BLOCK, etc. etc. etc.

[MPTech]

I picked up all of the donor parts for my build locally (didn't tear a car down, the wife and HOA would hear of it).

Anyways, I also turned in my booster for a new one from the auto parts store for the reason mentioned above.

Another point: I also saved the M/C distribution block, with the lines cut leading away from it (left the lines between the block and M/C intact). But when I went to run my brake lines with my friend's help (he's on his 3rd roadster build), he convinced me to not run the block and I agreed with him. I understood the block to accomplish 2 main functions. Proportion more brakes to the front (don't need that) and in-case of a brake failure (front or rear), it would shut-off the failure (not necessary with dual M/C) so what was the point of running the block? (I may be wrong, this was my understanding, if I remember correctly). I know it simplified my brake lines and cleaned them up, not having to run it and I'm all for that.
Please correct me if any of this information is incorrect.

[Gale K]

MP, from my (foggy) memory, that sounds about right. The prop valve can be gutted (that I know for sure) and Fortes (and others--I got mine from Fortes) sell a plug you can use when you gut it. This changes the proportioning from stock (set for the Mustang, nose heavy) to be more balanced (appropriate for the FFR, less nose heavy).

The foggier memories for me are the fail-safe portion. I "believe" with the stock Mustang, single reservoir master cylinder, the distribution block was designed to function as a fail-safe. If the rear brake line is compromised for instance (fluid loss and leaking), the fail-safe will shift (based on pressure) to allow fluid to flow only to the front, allowing you to still use front brakes. Same goes if the front line is compromised. I will go do a little searching. I know dv/dt posted a pretty good write-up on the 'other' forum a few years ago complete with quotes from the Ford shop documetation.

I decided to keep mine as I am using the stock master cylinder from the donor.