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ugh!!!! these brakes

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f3nix

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so ive had my beauitiful (on the inside) TR4A for almost 3 years now, and just last night, i was finally able to bring it home from my friend's property. but now that i have it, i need to finally finish up this project. if you like stories, please read on... if you just have some useful advise, and would rather not hear my tale, please skip ahead to the "***".

so this project started almost 11 months ago. i was taking my lady back home for the night and i noticed that it felt like the u-joints for the irs were wearing out. so the next morning i jacked up the rear to check everything out. to my surprise, two of the diff mounts were completely ripped through the frame, which is from what i know now to be a fairly common problem. no biggy i thought, ill just go onto mossmotors.com and order myself some new mounting rubber and weld up my problem. well, turns out that the gas tank is <i>very</i> close to where i was welding. my friends and i were doing a project that required welding fairly close to the gas tank on his truck, and even after he drained out all of the gas, he ended up buying a new gas tank. (long story for another time). i now thought to myself "well all of these body mounting points have 40 year old rubber on them, i should lift the body and replace those at the same time." so one week later, i had the body off, the frame welded up and new rubber on the way i was very content. next thing i knew, my poor tr had been body-less for over 2 months! (school can be horrible sometimes) so i rallied together some buddies, and that weekend we got the body back on and bolted up. over the next week i proceeded to finish getting the engine compartment in order so i could take kim out for another drive in her favorite car. well, luckily, she has more common sense than me sometimes (i <i>was</i> in a hurry) and she reminded me to bleed the brakes before our test drive, smart girl. so i crawled under the back and told her to start pumping the brakes and she said "umm, the pedals not getting any stiffer". so i look around and notice that ive got the line leaking from the 4 way tee right off of the master cylinder. well by that time justin rolls around. its getting to be 10 pm, and all of the auto stores could now be considered closed. well justin had this great idea, "ive got some jb weld in the back of my truck!, we can use that!" oh if i had just waited till the next day for a new brake line... but i didnt and we gave up after 11:30, so that kim and i could make the 12 o clock show. over the next month, my friends were going to try to fix this ever persistent leak with.... more jb weld. their valiant efforts have now left me with having to redo that entire part of the brake system. the problem of course with doing that part of the brake system is that i now need to find a new restrictor valve.

*** so my question is this: where do you suppose i could find a restrictor valve for my TR4A with irs, or do i even need it on there? im afraid that if it is not on, then i will send too much pressure to those drums in the back and lock them up constantly. what would you guys do? im very eager to drive my tr again.
 
The restrictor valve was not always fitted to Tr4A's. It's function is to maintain residual pressure to the front calipers so as to lessen pedal travel by not allowing the pads to retract as fully as if there was no residual pressure. This valve does not affect rear brake proportioning.
 
Don't lose your ladyfriend! Especially if she likes the cars.
But beware, next time if she tells you to test the brakes out on the road alone....
 
just remember that the valve you ar talking about is called a "residual pressure" valve....and it works just like Merlin said it does...
 
Hi. My TR6 got brand new discs and calipers. Hadta brake hard to make a stop light. Then after 10 highway miles the brakes are squeeking.
Got home and BOTH the calipers were dragging bad. The next morning the calipers were free but the rotors were blue/black.
Whats the likely cause ?
Bentley doesnt cover the PDWA op, only R&R. Easy to dismantle?
thx Dave
 
Did you replace the rubber hoses to the calipers? If they're as old as the car, they could be breaking down inside. When that happens, they can act much like a one-way valve and not allow pressure to release. That seems as likely as anything, since I wouldn't expect "new" calipers to bind up unless they were bad before they went on the car.

I'd be a bit concerned about those rotors, but I'm not enough of a metallurgist to know if they're ruined or not.

Oh, and don't even think about the PDWA unless it's leaking. It has NOTHING whatsoever to do with anything except DETECTING a pressure difference between front and rear brake circuits. Beyond that, it's essentially just a pass-through for brake fluid and does not maintain, alter or otherwise affect pressure to either circuit.
 
As far as the discs, they're no worse off than for 30 min of racing. Now the pads and dust boots are another matter. I'm not sure how the new 'organic' pads put up with misuse and the boots might be a bit crispy. I will second the potential hose problem/cause.

Tom Lains
TS8651 & 58107
 
previous post:
Hi. My TR6 got brand new discs and calipers. Hadta brake hard to make a stop light. Then after 10 highway miles the brakes are squeeking.
Got home and BOTH the calipers were dragging bad. The next morning the calipers were free but the rotors were blue/black.
Whats the likely cause ?
Bentley doesnt cover the PDWA op, only R&R. Easy to dismantle?
thx Dave

Thanks da both a yus! The hoses were new as well. I found the BuckeyeTriumph site has an excellent Dx section for brakes. Indications are either the servo or MC at fault.
The brakes were loose the next morning. First tried braking hard with the engine off; no probs. Started it and tryed again; still OK. Rode around the block jamming the brakes ;OK . Guess I'll hafta hit the interstate to get it warm...
 
I chased down a hanging/binding brake problem on my Celica once. Here's what I did (in order):

Replace Caliper
Replaced Proportioning Valve
Replace Master Cylinder
...All to no avail...
It turned out that new fluid was the fix. It was probably saturated with water, and where the brake line went behind the engine at the firewall, it was creating a vapor lock.
Expensive lesson. Change your fluid at least every 2 yrs.
 
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