Powermaster Pump Troubleshooting

[iNfested]

Hey I've read all the stickies but would appreciate some input/feedback. My powermaster pump would not stop running as long as the key was in the ignition system or while the engine was running and it was accompanied with a solid brake warning light. Having replaced the accumulator the brake warning light no longer appears however the pump continues to run. I am assuming this is due to an internal leak however before I tear into it would be great to have some feedback on the subject.

Please neglect to mention suggestions of converting to hydroboost, manual, vacuum or parachute/fred flinstone thanks.

 

[daninmich]

I am having the same issue. I have that diagnostic service tool and the system is pressurizing to 540 and cycles off at 770. It just keeps cycling between 540 to 770.

When I turn off the ignition it bleeds off and doesn't suddenly drop to at 200psi to zero?

Is it the motor?
A leak?
Accumulator??

 

[gsgnnut]

I feel you pain gentlemen. Been there done that 3 plus times over 20 years. I finally got smart last year and dumped the power disaster for a vacuum set up. only wish I got smart 19 years ago before replacing the PM 3 separate times for stupid money. Vacuum conversion is simple, inexpensive, tried ,true and a no brainer.

 

[daninmich]

I know. Just hoping its that accumulator but this thread seems like my issue.

 

[gsgnnut]

today its the accumulator, tomorrow the pressure switch, next week the pump, and it just never ends. The real problem is the FACT that The PM braking system is NOTOROUS for sudden failure WITHOUT any warning. I survived 3 such sudden failures and except for the grace of god did not hurt myself or anyone else or wreck, although it was real close on all counts. after the 3rd sudden failure , the light bulb in the skull lit up saying its just not worth the risk to gamble with PM's. I've been driving 40 yrs and driven hundreds of cars of every kind and The GN is the only car that tried to kill me- and 3 times!!!!. Answer this question - how many times have you experienced sudden, totally unexpected brake failure in ANY non PM car? Exactly, Ive never had a vacuum brake failure and trust me I've driven some real P.O.S.! The fact that the GN sudden failed 3 times is either an omen for me to quit driving or the PM is terrible engineering. No surprise on my opinion. If you don't want to listen to me Give Cotton's performance a call and ask him his opinion on the subject. He will make my rant seem mild.

 

[TurboBuick86]

It's ur pump that's weak. Same thing happen to me. Took my master cylinder apart & rebuilt it, new accumulator too & same thing. Replaced pump motor & problem solved. Hope that helps.


Posted from the TurboBuick.Com mobile app

 

[standupjskiguy]

I experienced the motor continue to run, like you describe, a week ago. The motor was real hot too!
I replaced the brake fluid with dot 4. I've heard you should replace the fluid every year.
Moisture gets in and lowers the boiling point of the fluid. The fluid going through the pump gets hot
so I assume it may boil inside the pump and create gas so the pressure never gets high enough to shut off.
(My switch is only a year old.) Since the change of fluid, it seems fine now but I don't drive it all that much.
I'd try changing the fluid and go with dot 4.
If you loose pressure when the car just sits, that is caused by wear or porosity on the assist valve inside
the master cylinder. It's one of the first assemblys inside after you removed the circlip. If there is no porosity
from rust etc., you can spin the pieces and polish out the step or wear ring that causes the leak-down.
(It's not for the faint of heart)

 

[davelostmissing]

http://www.turbobuick.com/forums/threads/power-master-check-valve.390235/