Power master Troubles (Reman Unit)

wiseman

Active Member
Joined
Jul 4, 2011
I just purchased and installed a fresh, newly remanufactured power master unit from cardone. I followed all instructions supplied with the unit along with the instructions (bleeding procedure) in this forum to the tee. The install went well, and the unit performed flawlessly yesterday. I took it on a 10mile trip and back, with no problems.

But, today my brake light is back on, the brake pedal feels hard sometimes but can be pushed all the way to the floor using constant pressure, and the motor "constantly" runs. I was stopping it after 20secs, but when the car is running, it constantly runs. Also, when I pump the brakes, brake fluid constantly leaks out of the rear of the bowl. so I will not be driving my GN, again. I didn't want to convert to hydroboost, but this is getting to be a big pain. I waited for 4wks for my present unit to come in, and I am frustrated now. I have checked for leaks, none found including rear cylinders.

Is it common for newly rebuilt units to be faulty. From the power master trouble shooting section, I believe that it may be leaking internally (from a new rebuild unit)? Any thoughts? Thanks....
 
Switch to vacuum and be done forever. Hydroboost is a close 2nd. Drop the PM unless you only race. It's not safe on a street car. That's why it was so short lived.
 
I just purchased and installed a fresh, newly remanufactured power master unit from cardone. I followed all instructions supplied with the unit along with the instructions (bleeding procedure) in this forum to the tee. The install went well, and the unit performed flawlessly yesterday. I took it on a 10mile trip and back, with no problems.

But, today my brake light is back on, the brake pedal feels hard sometimes but can be pushed all the way to the floor using constant pressure, and the motor "constantly" runs. I was stopping it after 20secs, but when the car is running, it constantly runs. Also, when I pump the brakes, brake fluid constantly leaks out of the rear of the bowl. so I will not be driving my GN, again. I didn't want to convert to hydroboost, but this is getting to be a big pain. I waited for 4wks for my present unit to come in, and I am frustrated now. I have checked for leaks, none found including rear cylinders.

Is it common for newly rebuilt units to be faulty. From the power master trouble shooting section, I believe that it may be leaking internally (from a new rebuild unit)? Any thoughts? Thanks....


http://www.turbobuick.com/forums/threads/cardone-rebuilt-power-master-issues.373632/

And you can add one of mine to the statistic. I'll be calling Dennis on monday.
 
I have the same problem, motor runs continous after test drive Temp at PM motor 130 F. I replaced the motor with the one I removed and everything is perfect now. Cycle time 4-5sec at any Temp. 10 pump cycle 14 seconds. The pump that came with the rebuild had 8sec cycle at 80F and 25 sec at 10 pump down, when the temp goes up the pump time got longer until it ran continous and the tank level stayed high.

Took the car to the 1/8 mile drags and 150 mile drive with my old pump last night everything worked perfect. The PROBLEM I talked with Cardone and the WILL NOT take the pump back and check it only the entire unit. I gave the tech the test proceedures and temps to add to there testing of the rebuilt units but I dont have any confidence that they really care.

I have decided to keep my unit and see if I can learn to rebuild the pumps myself.

P.S. If anyone knows of a rebuld procedure for the pump please contact me, I am also looking for a new seal kit for the cylinder I removed it had a slow bypass problem.

Thanks, hope this info helps others,
Steve
 
By "cycle" you mean recharge time? How long for a "cycle" - ie; once pumped up and left alone, any leakdown to where the motor restarts?
 
Yes, recharge time. Recharge 4-5seconds after 2-3 presses on the brake pedal. Full discharge 10 presses 14-16 seconds. No leakdown in 24 hours period.
 
And add one more just bought a REBUILT unit and the P.O.S is leaking at the motor ..600.00 ,,,,,,,,,,,, two days wasted install, crapy product= priceless
I was going to try not to vent but fyi in the ad they do say sometimes they rebuild the motors?????
 
Something to try, something to look for:

Let the unit cool down to ambient temp. Pump the brakes to discharge the accumulator to complete discharge
Key on and let the PM motor run. Watch the level come down as the pump runs and fills the accumulator. It should shut off when its finished.

Watch the unit and see if it holds pressure or if it leaks back into the reservoir. If it's leaking you can actually watch the reservoir level rise while it leaks. A really good powermaster will hold pressure and never leak, even if it sits for a week.

If it's leaking, You can identify the leak path by placing a finger over one of the holes in the bottom of the pump side reservoir and feeling for the back flow.

If the flow is coming from the suction side (hose) of the pump, then it's just a leaky check valve.

If the flow is coming from the return port, then the master cylinder is leaking internally. Send the unit back.

If the check valve is leaking, (pump the brakes to discharge the accumulator) you can remove the accumulator and remove the high pressure hose from the master cylinder and pull the check valve out and inspect it and clean it. Use a small easy-out extractor to pull the check valve body out of the master cylinder, and then a magnet to pull the check poppit out itself. If the check valve rubber seat seal is deformed you will see it. Lol either way if it needs anything more than a cleaning, send it back I guess. It's cardone's problem. A deformed check seat seal would need to replaced.

if the check valve components look good, you can clean it with compressed air and put it back in. Check in the reservoir for any indication of any debris at all. Even the tiniest little specs will cause problems. If you see anything, clean it out and try to get it as clean as possible. Fill with fresh fluid and run the unit through a cycle to see if it will stop leaking.
 
Something to try, something to look for:

Let the unit cool down to ambient temp. Pump the brakes to discharge the accumulator to complete discharge
Key on and let the PM motor run. Watch the level come down as the pump runs and fills the accumulator. It should shut off when its finished.

Watch the unit and see if it holds pressure or if it leaks back into the reservoir. If it's leaking you can actually watch the reservoir level rise while it leaks. A really good powermaster will hold pressure and never leak, even if it sits for a week.

If it's leaking, You can identify the leak path by placing a finger over one of the holes in the bottom of the pump side reservoir and feeling for the back flow.

If the flow is coming from the suction side (hose) of the pump, then it's just a leaky check valve.

If the flow is coming from the return port, then the master cylinder is leaking internally. Send the unit back.

If the check valve is leaking, (pump the brakes to discharge the accumulator) you can remove the accumulator and remove the high pressure hose from the master cylinder and pull the check valve out and inspect it and clean it. Use a small easy-out extractor to pull the check valve body out of the master cylinder, and then a magnet to pull the check poppit out itself. If the check valve rubber seat seal is deformed you will see it. Lol either way if it needs anything more than a cleaning, send it back I guess. It's cardone's problem. A deformed check seat seal would need to replaced.

if the check valve components look good, you can clean it with compressed air and put it back in. Check in the reservoir for any indication of any debris at all. Even the tiniest little specs will cause problems. If you see anything, clean it out and try to get it as clean as possible. Fill with fresh fluid and run the unit through a cycle
 
Thanks for your reply that was quick I will do the testes I hope to have some positive results,,,,,,,, I'm really bummed because I've been working on this thing out in a hundred-degree heat trying to get it ready for Jimmy's Car Show next week
 
Switch to vacuum and be done forever. Hydroboost is a close 2nd. Drop the PM unless you only race. It's not safe on a street car. That's why it was so short lived.
I played with my powermaster many times after almost crashing numerous times. After all that's been said about the unit on this site I did the conversion and never looked back. Brakes work fine and ALL the time!
 
By "cycle" you mean recharge time? How long for a "cycle" - ie; once pumped up and left alone, any leakdown to where the motor restarts?
Listen to these guys. Dump the power disaster before it kills you or someone else. The noveltie is not worth it. Vacuum is cheap easy tested tried and extremely reliable. Hydroboost is also reliable but a bit more expensive than vacuum set up. I wish I had all the money back I wasted on pm's. I too had several close calls before realizing the pm was a time bomb that had to go.
 
By "cycle" you mean recharge time? How long for a "cycle" - ie; once pumped up and left alone, any leakdown to where the motor restarts?
Listen to these guys. Dump the power disaster before it kills you or someone else. The noveltie is not worth it. Vacuum is cheap easy tested tried and extremely reliable. Hydroboost is also reliable but a bit more expensive than vacuum set up. I wish I had all the money back I wasted on pm's. I too had several close calls before realizing the pm was a time bomb that had to go.
 
By "cycle" you mean recharge time? How long for a "cycle" - ie; once pumped up and left alone, any leakdown to where the motor restarts?
Listen to these guys. Dump the power disaster before it kills you or someone else. The noveltie is not worth it. Vacuum is cheap easy tested tried and extremely reliable. Hydroboost is also reliable but a bit more expensive than vacuum set up. I wish I had all the money back I wasted on pm's. I too had several close calls before realizing the pm was a time bomb that had to go.
 
Thanks for your reply that was quick I will do the testes I hope to have some positive results,,,,,,,, I'm really bummed because I've been working on this thing out in a hundred-degree heat trying to get it ready for Jimmy's Car Show next week
I'll be at Jimmy's next week. Hopefully you get sorted out by then.
The old powermaster has a horrible rep, but I've learned over the years that it does work well and reliably if you pay some attention to it. Change the fluid out regularly, at least once per year. And when the car is going to sit parked in the garage for a few days or more, go ahead the de-pressurize the powermaster by gently pumping the brakes with the key off. That way it's not sitting there doing nothing with 750psi of pressure built up in it for days or weeks on end.

But I'm definitely not going to tell anyone that vacuum brakes don't work well or that it's a bad idea......
 
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Thanks for your reply that was quick I will do the testes I hope to have some positive results,,,,,,,, I'm really bummed because I've been working on this thing out in a hundred-degree heat trying to get it ready for Jimmy's Car Show next week
I'll be at Jimmy's next week. Hopefully you get sorted out by then.
The old powermaster has a horrible rep, but I've learned over the years that it does work well and reliably if you pay some attention to it. Change the fluid out regularly, at least once per year. And when the car is going to sit parked in the garage for a few days or more, go ahead the de-pressurize the powermaster by pumping the brakes with the key off. That way it's not sitting there doing nothing with 750psi of pressure built up in it for days or weeks on end.

But I'm definitely not going to tell anyone that vacuum brakes don't work well or that it's a bad idea to convert to vac....
 
I just purchased and installed a fresh, newly remanufactured power master unit from cardone. I followed all instructions supplied with the unit along with the instructions (bleeding procedure) in this forum to the tee. The install went well, and the unit performed flawlessly yesterday. I took it on a 10mile trip and back, with no problems.

But, today my brake light is back on, the brake pedal feels hard sometimes but can be pushed all the way to the floor using constant pressure, and the motor "constantly" runs. I was stopping it after 20secs, but when the car is running, it constantly runs. Also, when I pump the brakes, brake fluid constantly leaks out of the rear of the bowl. so I will not be driving my GN, again. I didn't want to convert to hydroboost, but this is getting to be a big pain. I waited for 4wks for my present unit to come in, and I am frustrated now. I have checked for leaks, none found including rear cylinders.

Is it common for newly rebuilt units to be faulty. From the power master trouble shooting section, I believe that it may be leaking internally (from a new rebuild unit)? Any thoughts? Thanks....
You bought a Powermaster from a company that can't rebuild a paper clip.
 
If the electric motor is running constant mostly likely the seals in the pump are faulty that will cause the motor to run constant. It will work for a while once hot the result will be everything you described i.e. Brake light, hard pedal or pedal going to the floor. Exactly what I experienced with mine so do away with it before you waste more $. I switched to vacuum and no problems works just the same.
 
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