ABS issue

neverfastenough

Registered User
Ive had almost every problem possible with this ABS on my sc, except the pump. Ive had to put a new accumulator ball on, pressure switch, pump motor relay etc. Tonight, something new happened, I hit the brakes, everything felt fine, but the abs and brake light came on and stayed. I drove to a gas station, pump wouldnt quit running(key on). I figured I blew a line and it was pumping onto the ground, but no leaks. The pedal felt fine also. I drove 30min home, pump running the whole way. The pedal was normal most of the time, sometimes I had basically no brakes and got a buzz feeling in the pedal like the ball lost all of its prime. I doubt this is a pressure switch prob, and know its not the relay. Is it possible for a perfectly fine accumulator to just up and 100% fail. Its a reman about 2 years old. It normally pumps and you can hear the motor bog down a bit once the pressure is up and it kicks off. It just ran like it had normal load on it, and pitch increased a bit if I hit the pedal. To me it just seems like it wont hold pressure. I dont even know where to start tomorrow really, I guess I can put my spare accumulator on it.
Your thoughts?

Corey
 
I would try the spare accumulator and see if it changes anything.....

I've had pressure switches go bad and cause the pump motor to run all the time.....

I ran my 89 like that for over a year with no braking problems....

However, the pump motor eventually gave out and gave me the hard brake pedal.....:(
 
I've had pressure switches go bad and cause the pump motor to run all the time.....

I ran my 89 like that for over a year with no braking problems....

However, the pump motor eventually gave out and gave me the hard brake pedal.....:(

Ditto on this..... Same thing has happened to me before.
 
OK ill try the ball first. I cant drive the car like this, the brakes work or dont really, sometimes it has some pressure other times its empty.
 
It's the brown ABS pump relay on the passenger side firewall. This just happened to a friends and I've seen it at least a dozen times. Take a big screwdriver or steel rod and poke it really hard. The contacts in the relay are stuck together and that'll knock them open. Replace the relay.
 
It is either the brown ABS Pump motor Relay or the pressure switch. Changing the relay is the cheapest route to try first and the most likely. The accumulator is NOT part of the problem. as even if the internal diaphragm ruptured, eventually the system would reach the pressure needed to shut off the pump. It might not stay there long but it WOULD happen.
 
The "buzzing" you mentioned could very well be an indicator that the internal pressure relief valve is lifting inside the ABS Unit. Again this is an indicator that the relay isn't opening to ~~~~ the motor off OR that the pressure switch contacts are welded shut.

Have you resolved this issue yet?
 
The issue resolved itself, I went out the next morning it pumped until it had pressure and it kicked off. Continued to work fine up until #6 piston made its way to my oil pan. AFAIK its still ok.

Corey
 
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