Powermaster Problem

[BASS]

Ok, its been a while since I've been on here, but I seem to have a problem with the Powermaster, and not sure if this is a simple fix or a rebuild is required. I would like to keep the Powermaster system and not convert to vacuum setup.

The Good:

• I replaced the accumulator ball 2 years ago (unit from Highway Stars). Can't remember what the issue was 2 years ago on why I replaced it, but I believe it was because the pump motor was running too long for each cycle.
• I replaced the pressure switch today (new AC Delco unit)
• No brake lights come on, and the brake pedal feel is normal at all times of operations.
• No outer leaks visible with the unit.
• Brake fluid levels are correct on both sides of the reservoir.
• I did the key turned on (accessories on) diagnosis and sat in the car for over 40 minutes and the motor/pump did not kick on, which I believe is the test to make sure the check valve (underneath the accumulator ball) is OK and working correctly. I believe if its a bad check valve, the motor/pump would randomly kick on while the key is in accessory mode.

The Bad:

• On exactly EVERY third time that I press the brake pedal (whether I'm driving, idling, car off w/key turned on), the motor/pump would kick on for 5-7 seconds. I don't ever recall noticing this issue in the past. Is this supposed to be normal??
• There were a few times this month that the motor/pump kicked on after pressing on the brake pedal and it STAYED running for over 45 seconds straight, I got scared that I would burn out the motor/pump so I had to shut the car off. If this happened while I was driving with the windows down, I might not notice it and then I would really be in trouble if the motor/pump burns out.
• Powermaster is 100% original (with the exception of the 2-yr old accumulator ball and new pressure switch). Car was sitting for an extended period of time, and I should've de-pressurized (i.e. pumped down) the unit before I let the car sit for so long.

Is it safe to assume its the accumulator that's bad (maybe the diaphram/bladder went bad)? If you don't believe its the accumulator that's the issue, does this mean the unit needs a rebuild (i.e. internal problem)??

 

[Turbo6inKY]

Corrosion is a bitch.

The Powermaster was innovative, but not durable. That yours still mostly works is impressive.

The fix is getting rid of it. A Wilwood manual master can provide enough caliper pressure to lock up all four and will never fail if you keep the fluid fresh.

 

[BEATAV8]

Seal kits are available from richard clarks garage. Rebuilding the master cylinder is not a big deal even if you've never done it before.
If you have one of those newer & larger hydac accumulator balls on it, I have yet to see one of those go bad.

fresh fluid every year and de-pressurize when it's parked for a while, it will last a long long time.

 

[Warhorse465]

Powermaster diagnostic chart:

Google-Ergebnis für http://www.gnttype.org/techarea/images/diagchart.gif

Old fluid is the enemy of the diaphragm in the accumulator. Cheap insurance to change it once a year and depressurize before winter storage.

 

[Mr.Spool]

Ive got the og one still in one of my cars.
Did a switch and maybe 2 accumulator balls throughout its lifetime.
But.....
I take car of things like flush the fluid out and make sure it stays clean
I also run synthetic fluid in the power master as well.
I have found it to be all in all a very reliable system if maintained