I'm repainting my car as we speak, but I was pulling the car in and out of the garage the other day when my brake pedel went completely hard, still had brake but no power assist through the powermaster. So I did some checks and had power, fuse was fine, so I went further and checked power to the wires and ground. For some reason when I unplug the pressure switch and the pump connector all checks come back okay, but as soon as I plug i the pressure connector, my ground for my pump comes alive to power. So I cut the ground wire and regrounded it and now the pump is working again, but now everytime or every second time I press the brake I can hear the motor coming on ... I can't remember if it did this before, or is this normal? It was just a quick solution, anyone have any suggestions to what happened here?
Powermaster Question
- Thread starter BuickED
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A hard pedal is the classic symptom of a dead (or dying) acc ball. The wiring on the P/M is weird. I don't have my schematic with me today, but you should not need to change any wiring to make it work. Especially if it was working fine before the hard pedal.
I would say swap the wire back and run your diagnostics. Time tha acc ball and I'll be you find it's on it's way out.
Brake System
I would say swap the wire back and run your diagnostics. Time tha acc ball and I'll be you find it's on it's way out.
Brake System
No time?!
Does the motor "click" like it's trying to come on but really doesn't do anything but make a click sound? If so, your acc is blown. The pump is dead-heading.
If the motor does nothing at all, the I would agree.
Then it would be an electrical problem.
Does the motor "click" like it's trying to come on but really doesn't do anything but make a click sound? If so, your acc is blown. The pump is dead-heading.
If the motor does nothing at all, the I would agree.
Then it would be an electrical problem.
Oh, DUH!
Forgive me, I get caught up in so many mechanical failures.
I'm not used to the electrical ones.
By the schematic, the pressure switch and the motor itself ground at the same location. Pin C goes to ground from the switch, pin A goes to ground from the motor. Depending on what was hooked up and where you tested at, it may be Ok. If you tested the ground wires without them connected to ground, then you would see 12v there. Do things appear to be functoning with it wired the way you have it?
Maybe in the process of painting the car the original ground got compromised?
You motor running every other time you press the pedal is an indication of the pressure falling off a little quickly. This can be considered "normal" depending on how old the P/M is. Once you have the motor running to satisfaction, you can time it and find out more.
Forgive me, I get caught up in so many mechanical failures.
I'm not used to the electrical ones.
By the schematic, the pressure switch and the motor itself ground at the same location. Pin C goes to ground from the switch, pin A goes to ground from the motor. Depending on what was hooked up and where you tested at, it may be Ok. If you tested the ground wires without them connected to ground, then you would see 12v there. Do things appear to be functoning with it wired the way you have it?
Maybe in the process of painting the car the original ground got compromised?
You motor running every other time you press the pedal is an indication of the pressure falling off a little quickly. This can be considered "normal" depending on how old the P/M is. Once you have the motor running to satisfaction, you can time it and find out more.
Great, thanks .... It seems to be working fine the way I hooked it up, it just seems strange, the power master is still original, car has 160,000km on it. There is another electrical problem with it but I'm yet to trace that down yet.
I will time the action and see how it is, I just don't want to go to vacuum brakes just yet, I enjoy the power system
I will time the action and see how it is, I just don't want to go to vacuum brakes just yet, I enjoy the power system
Power Master Wiring
I know that on my '86 I had to add another ground as the one in the connector stopped working. And of course it was the connector on the PM motor not the harness and I found out after I ordered a new motor. It works well now with the second ground.
I know that on my '86 I had to add another ground as the one in the connector stopped working. And of course it was the connector on the PM motor not the harness and I found out after I ordered a new motor. It works well now with the second ground.
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