Power Master ???

[87WE4BOOSTED]

Hey guys,

How can I tell if the accumulator bowl is bad or if its the pump thats bad without buying one or the other first. When i turn the key to the run position i here the pump running and doesn't stop. Getting ready to buy the accumulator ball but want to make sure.

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[standupjskiguy]

The accumulator ball is pre-charged to a lot of pressure. If yours is bad it has lost it's pressure and it will consume all the brake
fluid in the reservoir and then the pump will suck air, gurgle and keep running. If it is not consuming the brake fluid, the pumps internals are not pumping fluid and the motor is just running.
Also as the accumulator goes bad, one step on the brake pedal causes the pump to run. With a good ball,
it takes a couple pumps before the pump runs.
Hope this helps

 

[TurboDave]

Certainly sounds like you've got an accumulator issue.

 

[87WE4BOOSTED]

Thanks for the reply! It does not appear it's consuming the brake fluid as the res is still full. So it sounds like the pump is bad?

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[GNONYX]

This PowerMaster Tool J-35126 is what use to test the Accumulator bowl, and also checks the motor, Pressure switch and all is working with the spec. that I also attached for anyone to read.
You check on EBay, and sometimes the price is around $30-$50.00 to as high of over $100.00

 

[87WE4BOOSTED]

^^Good advice. Getting ready to perform the trouble shooting tips from the .org site. I need this tool. Thanks for sharing!

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[standupjskiguy]

I should point out that there are two reservoirs, one for the brakes the other for the boost.
The one on the passenger side should go down as the fluid is pumped into the accumulator.

 

[BEATAV8]

the motor never stops running when keyed on? if that's the case, sounds like there's an internal leak that's preventing pressure build up.

 

[GNONYX]

the motor never stops running when keyed on? if that's the case, sounds like there's an internal leak that's preventing pressure build up.

I just to make a correction on your first part of statement claiming the motor never stops running when the keyed on, and the following statement is written from the manual itself:
To find out at what pressure the pump is shutting off, turn on the ignition, but should not pump any longer than 20 seconds at a time.
The pump should shut off when the pressure reading is in the range of 635 to 735 psi. If the pressure exceeds this range, the pressure switch is probably at fault. If the pressure is low and the pump continually tends to cycle longer than 20 seconds to reach operating pressure, the pump may be bad or there may be a bad check valve or a leak in the system.

 

[Dennis Kirban]

Figured I would chirp in. Be careful buying a used brake accumulator bowl make sure the source can verify it is good.

Cardone has moved their rebuilding facility of the powermasters back to Philadelphia mainly because we are their main buyer. They are finding now with cores we send them more bad motors than usual which slows down the rebuilding process. On the plus side the person that is rebuilding them did them for them over a dozen years ago so he has plenty of experience.

Usually again from a personal stand point the brake bowl fails gradually example your brake lite may flicker on when you first start the car....eventually that flicker becomes more frequent and stopping becomes a major chore.

GM had two versions of the brake bowl the all solid black one which you seldom see today due to age and the later one with the yellow silk screen writing and the nut on the exterior part of the bowl. The Cardone bowl being a replacement not designed for a restoration project is slightly bigger and virtually has had zero defects since it came on the market maybe 4-5 years ago now. We were the test bed for them. Somewhere someone owns one of my WE4s that has one of the very first Cardone brake bowls on it. The only change we suggested they make was the nut to tighten it was to thin and required an open wrench that I had to grind down the sides to fit it between the bowl and the body of the powermaster unit.

denniskirban@yahoo.com

 

[BEATAV8]

the new accumulators are great

 

[GNONYX]

Figured I would chirp in. Be careful buying a used brake accumulator bowl make sure the source can verify it is good.

GM had two versions of the brake bowl the all solid black one which you seldom see today due to age and the later one with the yellow silk screen writing and the nut on the exterior part of the bowl.

denniskirban@yahoo.com

Hi Dennis,

Is it possible to rebuilt the original bowl if one wants to do a restoration?

 

[standupjskiguy]

87we4 will probably need both a new pump and accumulator.
What happened to me, I once bought a used PM unit.
I put it on the car not knowing the check valve was in backwards so no pumped fluid could enter the accumulator.
The excess pressure broke the splines inside the pump. I had to replace my pump. Motor was good pump was bad.
It ran but made no pressure anymore.
So if the motor runs but does not make pressure, the pump itself might be bad. Not knowing the history of the car,
who knows how the pump got damaged.

 

[standupjskiguy]

"Is it possible to rebuilt the original bowl if one wants to do a restoration?"

I would guess it would not be practical because they have a bladder which probably degrades over time.
That would need to be replaced and the bowl re-welded and then charged with nitrogen.
They are charged I think, with liquid nitrogen and when it turns back to gas creates about 7-800 psi.
It kind of like the gas struts used on out hoods. Over time the nitrogen leaks out and they lose pressure.

 

[TommyV8]

The first Powermaster problem I had (present when I bought the car) manifested itself in the form of the brake warning light coming on each and every time I stepped on the brake pedal, but only for a second. The brakes were a little slow to respond, but they would finally grab after maybe a half second and the light would go off. Emergency braking just wouldn't happen; the pedal would be hard at first, then the pump would kick on and the car would finally stop just as my b-hole was in peak pucker form. I figured out that the accumulator bowl wasn't holding pressure, so I got a new one and all was well. Briefly. Shortly after that I was driving and the emergency brake light came on and stayed on, but the car was still braking normally. For about three or so stops. Then the pedal became hard and the pump wouldn't come on at all. I got it stopped and popped the hood to find some light smoke and a burning smell coming from the Powerdisaster. Apparently the pump had burned up (as all electric motors do eventually), probably due to being overtaxed by the bad accumulator ball. I then ditched the Powerbastard altogether for a vacuum setup. It sounds like your symptoms match my initial symptoms, so I hope this helps.

 

[TommyV8]

BTW the accumulator bowls usually degrade due to dirty/rusty brake fluid attacking the glue on the seals on the inside of the bowls. The previous owner probably didn't know how to maintain the car properly and never changed the brake fluid, which you need to do once a year with the Powermaster.

 

[aminga]

One of the most important points of the powermaster is keeping the fluid clean

 

[Phoff]

Hi Dennis,

Is it possible to rebuilt the original bowl if one wants to do a restoration?

They can't be rebuilt.

Pete