who'da thunk... 90 ste abs problems

[stockgp]

well, this thing is almost legal now. i have a HUGE rust hole i the pass side muffler and a tie rod end that's so bad i honestly thought the pass wheel was going to fly off the car.

 

anyhow, the abs is making it next to impossible to drive this car. the pedal is so firm i actually have to put a good bit of my weight on it to stop the car, and even then it doesn't stop well. the abs lights are on at all times.

 

the pads and rotors look fine. i unplugged the abs computer, unplugged the abs module, and removed the fusible links, fuses and relays in the abs electrical center.

 

now, anyone know what's wrong with it? other than changing the firewall plate and running new brake lines, what's involved in swapping to vacuum brakes? will the brake booster for an automatic gp be too big to fit in a 5 speed car (given that the master cylinder is right in that area)?

[Crazy K]

i would do the vacuum conversion man!

 

I'm 'stopped' on my 91 CS for now, but I got a donor brake system complete from a 94 Z34. yes, I am giving the car abs brakes. the abs is not funtional yet, but I did get the normal brakes to work... but they are now dismantled pending a 5 speed swap.

 

as long as your donor is a 3.1 powered car, the booster will be small and tight enough to fit. I also got the entire donor cars brake lines. nothing is stronger or fits better than OEM lines, just make sure they look good!

 

if you want to figure out whats wrong with your PM3 look no further

http://www.tpsgarage.com/TGP/brakes/powermaster.htm

[peeeot]

Hey man, it really sounds to me like you have lost power assist. When you say your ABS light(s) are on, do you mean both the amber "antilock" light AND the red "brake" light?

 

When your accumulator pressure drops below 1800 psi, the red light will come on and you could lose power assist. When you lose power assist, ONLY your front brakes are doing any stopping, and the effort increases by a whole lot. I've experienced it. I'd say it's at least twice as hard to stop, and may take almost twice as long (random estimate).

 

With the ignition on, you should be able to press the pedal to the floor (according to my shop manual). I'm not positive but I think that if your brake pedal feels the same when you're driving as it does with the ignition off, you're probably operating without power assist.

 

First check your brake fluid level and for leaks in the system, especially at the rear proportioning valve, which is right next to the fuel filter.

 

If everything checks out there, I'm in almost the same boat you are. I suspect the accumulator to be at fault but am not sure yet.

[stockgp]

peeeot, you've pretty much described my problem. i haven't checked with the ignition off or anything, but i'm also guessing i have no power assist. also, i've not been able to find any leaks and my brake fluid level is fine. kind of dark, but fine.

 

ken...man, ijust don't have that kind of time. i seriously thought about a conventional brake setup, considering i have my other 90 to strip parts from. however, i've been working like a mexiblackanese slave lately. i don't even have time to jack off any more.

 

also, there are a million other problems with this thing. servece engine son light came on today. car died once on me on my way home from work, can't figure out why. then, didn't want to restart until the 5th or 6th try. AND, when i filled the gtas tank earlier, about a half gallon came pouring back out of the freakin car. have yet to crawl under and se where it's coming from.

[peeeot]

That's rough... I hate it when the problems pile up.

 

If you're sure you don't have any brake system leaks and the level is good, then either your accumulator, pump/motor, motor relay, or pressure switch has probably failed.

 

The link that Crazy K provided lists combinations of symptoms associated with different parts. Have you tried depressurizing the system and noting the pump run time to repressurize? If it's really short (like mine is), like 10 seconds or less, signs point to the accumulator being shot.

 

 

[stockgp]

no i haven't. today is the first day i've had off in a while. i might give it a look later