PowerMaster Motor Cycling

[Vegas Turbo T]

Had the hard pedal accompanied by the brake light coming on. Fit a new accumulator that I got from G Body Parts.com. Solved the hard pedal and brake light issue immediately. The motor runs about 10 seconds after I depressurize the system and then turn the key which I think is okay.

Now while driving, the PowerMaster motor cycles for about 4-5 seconds after each brake application. Don't remember that happening on any of the other turbo regals I have had. Maybe I just never paid attention until now. I'm wondering if it is an air issue and bleeding is needed. If anyone has had similar issues I'd certainly appreciate hearing about it.

 

[KC87]

Had the hard pedal accompanied by the brake light coming on. Fit a new accumulator that I got from G Body Parts.com. Solved the hard pedal and brake light issue immediately. The motor runs about 10 seconds after I depressurize the system and then turn the key which I think is okay.

Now while driving, the PowerMaster motor cycles for about 4-5 seconds after each brake application. Don't remember that happening on any of the other turbo regals I have had. Maybe I just never paid attention until now. I'm wondering if it is an air issue and bleeding is needed. If anyone has had similar issues I'd certainly appreciate hearing about it.

Did you do anything that would let air into the system? 10-15 seconds is very good to re-pressurize so you must have a pretty good pump. Could be the pressure switch or possibly internal leak. If the pump runs too long it will overheat and blow a fuse. Keep us posted.

 

[RareT]

Does the pump cycle every time you turn the ignition key to on?

Try this, turn key on but do not start the Engine. Let car sit there like this for about 10 minutes or so. Listen to see if motor occasionally runs without you touching brake pedal. if the motor cycles without touching the brake pedal, the check valve needs removed and cleaned.

You should be able to get three sometimes four brake applications before the motor runs again

 

[earlbrown]

When you originally had the hard pedal with the light on, could you feel the motor slowly pull the pedal down when you were pushing on it?


You should get way more than just one single pump out of a brand new accumulator (as long as it's working and fully charged)

 

[Darkstar72]

My PM was doing the same thing early spring last year, replaced the pressure switch and all was well again. I would start with a new pressure switch and remove the check valve for a cleaning while you're messing around under the hood.

 

[BEATAV8]

Pressure switch....

 

[xtremexnyc]

When was the last time the fluid was changed?
Changing the fluid can help also.

 

[turbo nasty]

Had the hard pedal accompanied by the brake light coming on. Fit a new accumulator that I got from G Body Parts.com. Solved the hard pedal and brake light issue immediately. The motor runs about 10 seconds after I depressurize the system and then turn the key which I think is okay.

Now while driving, the PowerMaster motor cycles for about 4-5 seconds after each brake application. Don't remember that happening on any of the other turbo regals I have had. Maybe I just never paid attention until now. I'm wondering if it is an air issue and bleeding is needed. If anyone has had similar issues I'd certainly appreciate hearing about it.

Quck check for check valve is to leav key off. Press brake pedal about 15 times/till gets hard then turn key on engine off and the pump will pull inboard reservoir down to about a 1/4ish in roughly ten seconds. Mark brake fluid in inboard reservoir level with a grease pencil, tape, etc and let it sit for a few hours (It shouldnt move at all even over night!) and see if level rises if so check valve isn't holding and thats contributing to the pump cycling. After that verification then address the possibilty of bad switch

 

[Vegas Turbo T]

Thanks for all the great feedback above.

I can say the check valve is good. I allowed the PowerMaster motor to cycle until it turned off - about 10 seconds from full depressurize and turned off the key. The boost side of the reservoir went down to about close to about a half inch from the bottom. I marked the level and it held for 24 hours.

To reiterate, the only thing I did was to fit a new accumulator. In order to get the new accumulator on I had to unscrew the inlet tube fitting to get it out of the way, maybe that introduced air into the system.

I did notice the fluid that came out of the old accumulator had black flakes in it that disintegrated when I touched them, really weird. Photo is attached. I did not see any of the black flakes in the reservoir. I'm going to change the fluid tomorrow. and see how that goes.