Brake Problem


Apr 23, 2009
So periodically the brake light would flicker on and off. I thought nothing of it because I just did all of the brakes. Well, the other day I was in the car in stop and go traffic. I was stopped with my foot on the brake when the brake light came on and before I knew it the car started going forward. I did my best to avoid the car in front of me and ended up hitting a parked car on my right side. Low impact but caused a fair amount of damage to the parked car and messed up my front end (marker light, headlight, bumper filler etc). I had the car towed to my mechanic. He thought it was a rotted brake line because he could see fluid on the line under the driver side but when he got the car on the lift he saw that the brake lines were in mint condition and not rusted at all. He thinks that some thing happened with the powermaster unit that caused the fluid to come out of the top of the reservoir. The brake fluid is pretty dirty also. Does anyone have any idea what could have happened. What I should replace? Where I can get parts???? I have also heard of the vacuum brake conversion. Is this a good idea? Any advice would be appreciated.
To me, it sounds like your accumulator went bad....that big, black round ball on the left side of the powermaster.......just a thought...but this happened to me also, and by replacing that big, black round ball, my braking problems were over.

Bruce '87 Grand National
Replace the accumulater and change brake fluid often and keep the PM. I like the brakeing better over the vacuum set up
I replaced the accumulator when I bought the car 2 years ago. Can you replace individual parts on the powermaster system or do I need to buy the entire rebuilt unit?
accumulators aren't known for longevity unless you change the fluid annually (or more often). Check in the brakes section for the powermaster diagnostic procedure. It will help to figure out what part may have failed on your system. If it is the accumulator (it sounds like it but I'm no expert), when you replace it, be sure to replace ALL the fluid. Replace it every year after that, too. I think there's some guys that change it as often as they change their engine oil!!
It could be the master cylinder and they dont sell rebuild kits. The only one i no that sell a complete PM is Kirbans. These are rebuilt by A-1 Cardone
It could also be the grey sensor/switch on the back of the master cyl. When the switch is bad the brake light comes on and you loose your power brakes. Mine is going bad b/c I loose my power brakes occassionally but when I lightly tap on that switch the power brakes come back on.

I had the same problem except I was doing 40mph when I guy threw a u turn in front of me:eek: . Get rid of it and go vacuum or hydroboost. The power master is to unpredictable.Why take the chance of hitting something else or have it go out at the track when your doing 100+mph. If I remember correctly this one went out at 135mph. Thats a Gnx:(


  • BPG-Nats-2007_084.JPG
    15.6 KB · Views: 79