1979-1993 & 94 Conv [Subscribe to Daily Digest] |
Jeyi -- although this is frustrating, definitely not a reason to junk your car. I just went thru some ABS problems with an ABS system on my 90 SPG, and ended up replacing the entire system under the hood, but not the ECU. It was a "main valve" fault. Mine was malfunctioning to the point that I had no brakes whenever it was hot / above about 80 degrees outside.
See that you replaced the accumulator -- that's your first good move, its a common fault.
You do not need to hook up the computer to the diagnostic tool to read the fault codes. Since you have a 90+ model, you can read faults by a jumper wire -- basically go to townsendimports site --> then to "technical documents" --> ABS Brake troubleshooting in the site and you'll see a way to figure out how to read the fault codes. Print this out and take to your mechanic if needed. This might help.
In the meantime, so if I'm reading correctly, you always have the yellow antilock light on, but sometimes the red brake fluid light, right? My gut says that if your warning lights are operating normally, you probably have a "good" ECU (under the rear seat cushion on passenger side of car FYI). Just curious, was your car ever flooded / lots of water on floor -- this could easily kill that ECU by the way.
So, moving on, There are a # of things that could be wrong with your system:
1) System or pump relay
2) Electrical problems / harness problems / corroded connections or the like
3) the "new" accumulator could be bad if it wont pressurize. I tried 2 from salvage yards on my car, both were absolutely bad. woops !
4) could have a bad pressure switch or corroded pressure switch connection. the pressure thing is the switch that turns the pump on when the system pressure falls below a threshold, then off when its back up to a certain threshold.
5) Might have a bad ground at the master cylinder assembly right under the reservoir. This is pretty common and causes lots of flaky stuff
6) Could have a bad internal / flaky/leaky valve within the master cylinder assembly (what's underneath the fluid reservoir with the pump attached to it)
7) Bad ECU under rear seat
Couple things to answer that might help us troubleshoot:
1) How is your brake boost? Is the pedal rock hard / ie difficult to press? Or are your brakes operating normally.
2) IN the AM before you've started the car and its sat overnight. Look at the brake fluid reservoir. Is it "Full" ie up to the top? Then go start car... turn everything off. Do you hear a whirring pump noise... get out (set park brake!) and look underhood, is the level of fluid slowly decreasing ? If so, this means your pump is working (at least somewhat) and the accumulator is pressurizing.
Reply w/ answers and we'll help you out. I literally LAST MONTH took out the entire abs system and replaced it so I'm waaay too familiar. I also took apart every bit of the master cylinder/valve/pump/reservoir/pressure switch assembly trying to understand how it worked.
posted by 75.151.5...
, Tue, 6 Jan 2009 18:40:11
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