Power master brake unit or Accumulator

[SilverBulletGN]

My Brake light is on and the brake pedal is hard. I'm wondering does anyone know how to test if it's the Power master unit thats gone bad or the Accumulator. I would greatly appreciate the info as there is a big differance in price $529.00 PM or $ 179.00 Accumilator. This is an 87GN.

Thanks

 

[TurboBuRick]

Have you checked the fuse?

 

[SilverBulletGN]

Yes I did. All O.K.

 

[turbonut85]

Turn the IGN on and do not start the car, Have the hood open and listen for the pump motor to run...if your pedal is hard the pump should start. If the pump does not run or the fuse blows again...you need a new pump motor or brake switch --or a new PM unit. if the pump motor runs and shuts off in 7-15 seconds...and then starts itself within a couple minutes, it's the acc ball. I'm not an expert on these, but I just rebuilt mine and went through some of the same issues. Look up Zeus on the board...he is the expert. HTH ---Keith

 

[SilverBulletGN]

Thanks Turbonut85 for the info. It was the fuse like Turboburick had mentioned I did check the fuses I must have missed it the first time. The brakes work now however everytime I step on the brake I can hear the pump run for about 3 seconds. I read that 3-6 seconds is O.K. but my concern is it seams loud. While driving I can hear it everytime I step on the brake.

 

[SilverBulletGN]

Well the fuse keeps blowing. I guess I have to start looking for parts or the whole powermaster unit.

 

[GNRick]

The pump should only run every 3-4 times you step on the brake. I don't know about Kirban, but Autozone uses the same source-Cardone-and gives a lifetime warranty. I'm on my third one with them and will be bringing it in again soon as my pump runs on every 1-2 times I press the pedal. Probably bad accumulator.

 

[bnice]

Is there a kit someone sells to rebuild the powermaster? I think mine is about to go and I'd like to fix it myself if possible.

 

[GNRick]

I just checked with Kirban and he also offers a lifetime warranty. I did some checking and found the powermaster for 86 electra wagon at Autozone is $360, compared to over $600 for the GN version. Only visible difference seems to be the shape of the reservoir, and Kirban sells the reservoirs. I emailed Kirban to see if he knows if there is any other difference. If anybody wants one, maybe they should email Cardone and ask them if the Electra version would work on our cars. Can't beat the price since it includes all rebuilt parts (and maybe a new accumulator) with a warranty.

 

[ksmmspt]

No Brakes either

Turn the IGN on and do not start the car, Have the hood open and listen for the pump motor to run...if your pedal is hard the pump should start. If the pump does not run or the fuse blows again...you need a new pump motor or brake switch --or a new PM unit. if the pump motor runs and shuts off in 7-15 seconds...and then starts itself within a couple minutes, it's the acc ball. I'm not an expert on these, but I just rebuilt mine and went through some of the same issues. Look up Zeus on the board...he is the expert. HTH ---Keith

Keith,
Thanks for the info you listed. Don't mean to hijack the thread, but I just drove my 87 tonight and the pedal went hard with no light at all. I will check the fuse tomorrow as I did not hear the unit engage when I turned the key to the on position. Do you know how difficult it is to remove and replace the entire unit? Thanks for the help.

 

[turbonut85]

Keith,
Thanks for the info you listed. Don't mean to hijack the thread, but I just drove my 87 tonight and the pedal went hard with no light at all. I will check the fuse tomorrow as I did not hear the unit engage when I turned the key to the on position. Do you know how difficult it is to remove and replace the entire unit? Thanks for the help.

You are on the right track. See if the pump starts when you turn the key ON. If it doesn't, check the fuse. Fuse is blown...replace with the proper size...30amp I think. Do this with the IGN OFF. Then turn IGN ON and listen for the pump to run. If the fuse goes again the pump motor is shot. If the fuse is good, and the pump still does not run...the switch on the top of the unit might be the culprit. Do these checks before you commit to pulling the whole unit as it might not be neccessary. If the pump runs, but does not shut off in 20 seconds, (make SURE it does NOT run any longer than 20 sec!!! TIME IT!!) Then I would look at getting a new ACC ball. Again, the Acc ball replacement DOES NOT require removal of the whole unit either. If you have further ?'s PM me and I will give you my phone # so you can give me a shout...I suck at typing!! ---Keith

 

[ksmmspt]

You are on the right track. See if the pump starts when you turn the key ON. If it doesn't, check the fuse. Fuse is blown...replace with the proper size...30amp I think. Do this with the IGN OFF. Then turn IGN ON and listen for the pump to run. If the fuse goes again the pump motor is shot. If the fuse is good, and the pump still does not run...the switch on the top of the unit might be the culprit. Do these checks before you commit to pulling the whole unit as it might not be neccessary. If the pump runs, but does not shut off in 20 seconds, (make SURE it does NOT run any longer than 20 sec!!! TIME IT!!) Then I would look at getting a new ACC ball. Again, the Acc ball replacement DOES NOT require removal of the whole unit either. If you have further ?'s PM me and I will give you my phone # so you can give me a shout...I suck at typing!! ---Keith

OK, Keith.

My fuse is good. Upon reinstalling the fuse with the ign off, I hear the system energize briefly. When I turn the ign on, nothing happens. I pulled the fuse again and it is still intact...reinstall and turn the key with nothing happening with the pump motor. By your earlier post it looks like the switch on the top may be the problem. What do you think? Thanks again.