Anyone cut open an accumulator ball? What's inside?

Blazer406

Mechanical Engineer
Joined
May 2, 2002
In my quest to approach a way to "re-charge" an accumulator ball..... I was wondering exactly what was inside one? I have a bad one.... but it is my only bad one.... and if I cut it open..... I won't be able to attempt to recharge it. I was thinking about drilling a small hole through the bolt head on the accumulator ball and threading it to accept a fitting that could be used to charge the inside with nitrogen. This will work fine.. if there is a diaphram inside..... but if it is a closed bladder..... filled with nitrogen... it likely isn't going to work.

I have convinced myself after some thought... that it is probably a bladder that got put in there....but I am not sure..... If it were a diaphram.... my idea might have some merit.......

Any thoughts?
 
You might want to consider doing a search on this subject, it has been discussed quite a few times, or e-mail gfstbuick in Sacramento, who was also working on a way to repair/recharge/rework these. If this could be done economically, Kirban would be doing it instead of having new ones made in Germany to resale everywhere. HTH
 
The accumulator is just a round sphere with a rubber diaphragm inside. The diaphragm has a metal piece (similar to a solid metal washer) in the center of it. A gas is on the side of the diaphragm opposite the end that threads onto the powermaster. Brake fluid is on the other side of the accumulator. Richard Clark (GN and GNX collector and expert, friend of Kirban) had a cut open accumulator at the GS Nationals a couple of years ago when he gave a lecture on how the powermaster works. Richard said the only thing that goes wrong with the accululator is the glue that holds the diaphragm to the accululator goes bad - the gas leaks and the accumulator gas precharge is lost. He said the glue goes bad by old brake fluid becoming corrosive (moisture and air getting into it). He said to change the brake fluid in the resevior in the power master once a year - use a turkey baster to suck out the old fluid and refill with new fresh brake fluild will make the accululator last much, much longer. He also said the metal piece on the diaphragm is used to test the acculuator. He had a board with a large nail through it with the point filed off. He then placed a scale on the floor, the board with nail on it, and then inserted an accumulator on to the nail. By pressing down on the accumulator you can test the pounds of gas pressure the accululator has - I don't remember the correct/minimum pressure. The accumulator is really simple but no way to replair once the glue goes bad on the diaphragm. Richard Clark is one of the experts on the powermaster.

Craig
 
Well..... that is kinda interesting...... I wonder if it is possible for an accumulator to loose some of the pressure.....? Mine was marked 33 Bar..... which is 478.6 psi. My accumulator.....(the one I just replaced)... I don't think was completely bad...... I had brakes....but for like 1/4 second when you first hit the pedal.....the brake light came on..... and if you hit the brakes like a panic stop..... for 1/2 second or so the pedal was extra firm....then the brakes kicked in.....

This is my first turbo regal to mess with...... so I am not sure of common symptoms.... or if it is even possible for one to loose part of the pressure.......

In any case..... It wouldn't be to hard to drill a small hole through the nut on the back side......and install a nitrogen charging fitting..... with a little schrader valve......then charge it with 470 psi.....

If my accumulator was totally bad.... i.e the bad glue you were referring to was the problem........ What I want to do isn't going to work at all......

It was just an idea I had........
 
Well, if you drill it and brake fluid comes out, then it won't work, but if the nitrogen just leaked through the bladder, then it might work. Just a thought.
 
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