View Full Version : Is this normal?

05-31-2014, 08:53 AM
Abs pump went out on my 90 sc.....replaced with a good used one and reinstalled master cylinder, after filling with fluid and turning the ignition on, my pump runs constantly......is this normal until I bleed the brake lines?

05-31-2014, 09:23 AM
Any lights lit while it runs?

05-31-2014, 10:26 AM
Yes. Antilock and brake light

05-31-2014, 10:42 AM
I think normally when the pump runs all the time the issue is a stuck relay and/or bad pressure switch.

But in your case, the unit was removed/reinstalled, so it could just be a wiring issue.

Did you confirm the connection to the motor wasn't done backwards somehow? Is the pressure switch connection reliable? I'd check those and the relay.

Also, seen this? http://www.albeedigital.com/supercoupe/articles/abs-system.html

05-31-2014, 11:40 AM
Yes check all wires connectors are just the way they came off seems to be getting no pressure to the accumulator ball when I take the accumulator ball off no bubbles coming out still trying to figure something out

05-31-2014, 12:24 PM
See this thread about a missing washer and priming:


05-31-2014, 12:51 PM
I am really out of ideas I have removed the assembly twice now and checked everything thoroughly and still no pressure being built pump is working wonderful just no pressure being built

05-31-2014, 01:03 PM
What steps have you taken, exactly, in an attempt to prime the pump?

05-31-2014, 01:13 PM
I turn the pump on and cracked open the accumulator ball… I eventually took the ball all be way off and nothing is coming out where the ball threads in no air no fluid I cracked the hard line coming from the master cylinder down to the pump nothing coming out those either checked to make sure that my Coupler was still in and it is located perfectly

05-31-2014, 01:28 PM
Did you try pushing the brake pedal while the pump is running with the accumulator installed?

How old is the accumulator?

05-31-2014, 01:42 PM
I sure did....I have tried swapping accumulators with a known working one...nada...acts like its not getting fluid

05-31-2014, 01:53 PM
Not sure what else to suggest, sorry.

Maybe if you try hot wiring the pump motor to make it spin in both directions to see if that does anything different...

05-31-2014, 01:59 PM
I pulled it all back out of the car....gonna clean everything and try again.....very frustrated.....thanks so much for all your help.....I think the key is that the motor is running, but not pumping fluid

05-31-2014, 05:54 PM
I got it......took it all back apart...cleaned entire unit out, then I filled the pump up with fluid as best possible. Installed back in car and turned it on and bam it primed as went to full pressure! Bleed the brakes and all is well. No lights on and pump is building pressure perfectly! Thanks for all ur help

05-31-2014, 07:25 PM
Tough process to prime it, I guess, but whatever works. Thanks for the update and best of luck w/your SC.