need help with abs brake pump

i have 89 sc with that high doller abs brake pump, i put one off of a parts car the same year, that have, that worked ok befor i changed it, and the problem that i am having is when you step on the brake the brake light and abs light both light up for a second and and the pump motor will run, and the brake padle will be hard at frist and then get soft. Does this mean that the accumulator is bad or need to be blead?

How many times can you press the brake pedal w/o the pump cycling? You should have a few presses before the pump runs, if not, the accumulator could be going bad(losing its charge). I'm assuming the SC's have a pressure switch for the abs as well, that could also be another cause of your problem. What is the older brake system in the SC's called anyways? I have a GM car made around the same time w/ a high $/problematic ABS system in it(Powermaster III..haven't had any problems out of mine yet though).

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only need to push down once for pump to come on, dont know pump typ

Maybe a problem with the pressure switch or the ABS relay. I guess try swapping out the ABS relay first to see if that corrects the problem.

The pressure switch is on the valve body and is used to tell the pump when it needs to pump due to pressure dropping below a set point. If it's sticking, it may be hesitating to tell the pump to ...pump.

Check the relay first.

RedSCSpeedster said:

when you step on the brake the brake light and abs light both light up for a second and and the pump motor will run, and the brake padle will be hard at frist and then get soft. Does this mean that the accumulator is bad?

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Yes. The OEM ABS accumulators have a service life of about 10 years, then they start doing what you described. We don't know about the service life of aftermarket accumulators; might live anywhere from 2-10 years. As an extra precaution, you should replace the pump motor relay. Even though your problem doesn't sound like the relay, they can break also.

Need accumulators

Where can I get a new one?

Alot of us have picked them at www.priorreman.com

110.00 shipped I beleive. At least that is what I paid two years ago.

Jeff B.