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Discussion Starter #1 (Edited)
The other day on my way to work the ABS light went on and the pedal went stiff and braking became quite difficult. Came home, read through a bunch of threads regarding what the problem could be and checked the ABS fuse in the engine bay, and it was was fine.

The sensors shouldn't be suspect

Replaced the trunk-mounted ABS computer with a working spare, connected the battery back up and the ABS worked again (perhaps even better than ever before).

Drove to work today and the same thing happened: light on, stiff pedal, difficult braking. The pump is not running when I turn the key, but was running last night after replacing the CPU and reconnecting the battery.

Does anyone have any idea what the issue may be? I thought the pump had gone bad, but since it ran after replacing the computer (which I found quite odd to start with...) I no longer think that to be the case...
 

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Hi Matt,
I experienced the dead pedal a few times with that car and it was always in the summer. I decided that the pump quit when it was too hot. My solution was that rough looking heat shield that came with the car. Are you using it?
 

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Discussion Starter #3 (Edited)
Hi Matt,
I experienced the dead pedal a few times with that car and it was always in the summer. I decided that the pump quit when it was too hot. My solution was that rough looking heat shield that came with the car. Are you using it?
Yes I am. I never take it out, even during the winter months. What baffles me though is that I drove the car around, it warmed up, ABS still worked fine, let it cool down, drove it later and it worked again but then stopped halfway to work, again.

What else confused me is that the pump was not even running until I swapped out the ECU, but ran fine after that, despite the car being cold...
 

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Matt,
Could be the pump on its way out or loose/corroded connection.

The pump won't always run when you turn the key on. Only if the pressure has been depleted from the accumulator.

Quick and dirty test: with the ignition off pump the brake to the floor 25 times. (this will fully deplete the accumulator.) Then turn the key to the on position. The pump should then run long enough to determine if it's functioning. If it doesn't turn on after that there is a problem.
 

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Discussion Starter #5
Matt,
Could be the pump on its way out or loose/corroded connection.

The pump won't always run when you turn the key on. Only if the pressure has been depleted from the accumulator.

Quick and dirty test: with the ignition off pump the brake to the floor 25 times. (this will fully deplete the accumulator.) Then turn the key to the on position. The pump should then run long enough to determine if it's functioning. If it doesn't turn on after that there is a problem.
Oh yeah, that's what I did. And I stopped on the side of the road and pumped the brakes and didn't hear the pump when the light when on this morning and when it happened the first time. There's a two pronged connector on the actual pump itself: is one of the prongs supposed to be powered?
 

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might be the brushes is worn out.
BTW I just ordered a new one for my gold and found a good price at white racing products.
the GM one. if you need to get a new one.
 

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BTW I would check with a meter at the motor if you get voltage when you turn the key.
if you get the voltage at the 2 thick wires feeding the pump and it does not run the pump is bad. but it might also be a bad fuse or relay. if there is no voltage at the motor
 

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Discussion Starter #8
Well, I played with some wires and fooled around with some things again and the culprit is the connector to power the pump. The wires going in must have been loose in the connector, so when I unplugged and replugged in the wires yesterday that temporarily fixed the problem. I just tightened the wires in the connector a bit and tried to reroute the connector so it is more slacked and it seems to have fixed it. In 45 minutes of driving just now though there were no issues, so I think I can call this one solved, or at least "figured out". Thanks for the help!
 

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-Solved?.

But i just want to add something i experianced lately. My pump was suddenly not running anymore, also had some problems in the past..
i turned the key to ignition, and put a multimeter on the leads, only getting 9v :eek:.. did some more measurements, and the culprit was the earth wire.. not knowing where it gets its earth from, i just cut the wire, and directly wired it to earth at the battery.
pump worked again. with strong 12v
 
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