Powermaster problems

[billygeg]

Hey Guys
My brakes give me trouble usually for the first few minutes when I take it out every few months..I usually get a hard brake pedal then it goes to normal with no issues..I took the car out the other day and the pedal never got soft...I have heard threw many threads all about the accumulator..When I bought the car the guy gave me one new in box so I replaced it..Same thing, Hard pedal..Now I am hearing about the pressure switch..I read up alittle bit on how to test it and it says there should be continuity between all terminals on the three pressure switch terminals..Not so..there are three terminlas on the unit..Lets call them A, B, and C..I get no continuity from A to B but I get a half second of continuity from B to C..I was also told that I could jump it out..So I turned the car on and jumped out the connector for the pressure switch..Like a dumb ass I forgot to put the pressure switch back in..Anyway, I do know that the pump is working because I got a small geyser shooting up from the hole the pressure switch is mounted to! DUH!..So I think (you guys tell me) that the electrical and the motor seem to work..Can I assume that the pressure switch is bad because I do not have continuity between the terminals on the pressure switch as stated in the directions on how to test it? Im just checking to make sure I understood the directions on checking it properly... If the switch is the problem does anyone knopw where I can buy one..I went to advance auto and they cant even get it..

 

[Gene Van Horn]

Get ahold of kirbans or maybe richard clarkes, either may have one for sale.

 

[billygeg]

Get ahold of kirbans or maybe richard clarkes, either may have one for sale.

Was kinda hoping to get one by tomorrow so I can get out this weekend! No one in any autoparts store would have one? Also, Do you think thats definitely the issue? I was at advance auto today, They had a picture and a price of $160 but couldnt get it..Id hate to spend $160 on something I dont need...

 

[BEATAV8]

Kirban, Highway Stars, etc. Switches are easy to get.
Pick up one of the powermaster diagnostic booklets too. I think Kirban sells those.

When I know my car will be parked for more than a day, I depressurize the powermaster by keying off and pumping the pedal gently several times until the accumulator charge is spent. Then the next time I key up, I listen for the powermaster to run and pressurize and stop. Then I start the engine. In this manner, the powermaster is "parked" with no pressure stored in it. I think this helps the seals and the pressure switch last much longer than leaving the unit parked with full pressure build in it. Doing this for storage and changing the fluid once per season has kept my powermasters in my 2 cars working great for more than 15 years now.

 

[BEATAV8]

http://www.gnttype.org/techarea/brakes/PwrMstr.html

http://www.turbobuick.com/threads/powermaster-brakes-diagnostic-information.362564/

 

[billygeg]

Kirban, Highway Stars, etc. Switches are easy to get.
Pick up one of the powermaster diagnostic booklets too. I think Kirban sells those.

When I know my car will be parked for more than a day, I depressurize the powermaster by keying off and pumping the pedal gently several times until the accumulator charge is spent. Then the next time I key up, I listen for the powermaster to run and pressurize and stop. Then I start the engine. In this manner, the powermaster is "parked" with no pressure stored in it. I think this helps the seals and the pressure switch last much longer than leaving the unit parked with full pressure build in it. Doing this for storage and changing the fluid once per season has kept my powermasters in my 2 cars working great for more than 15 years now.

Thanks thats great info to know! Once I get this thing figured out I will make sure I do that because this car isnt a daily driver..It gets out maybe a dozen times in the summer and sits for most of the winter in my garage...

 

[billygeg]

Is it possible that although my powermaster motor is running that it could be weak? Like I said it did shoot out some fluid from the pressure sensor port but it only went up about 2 inches and I never really heard this pump run..Never heard a buzz or hum from it when I started the car ever..Then Again, I never listened for it.. But even when I powered it up by jumping out the pressure sensor..I heard the relay click but no motor noise..It did shot out fluid as soon as I jumped out the terminals for the sensor so it must have been running no?

 

[BEATAV8]

it might run but it might be weak, or the check valve might be leaking.

put the switch back in and re-connect it. turn the key on (engine off) and watch / listen. The pump should run and build pressure for around 15-20 seconds, and then the switch should click once and the shut the motor off.

after that it should just sit there like that doing nothing at all until you press the brake pedal 2 or maybe 3 times. Then it should run again for a few seconds, click, and stop.

if it runs continuously, runs repeatedly with no pedal use, or never runs at all. something is wrong.....

 

[billygeg]

it might run but it might be weak, or the check valve might be leaking.

put the switch back in and re-connect it. turn the key on (engine off) and watch / listen. The pump should run and build pressure for around 15-20 seconds, and then the switch should click once and the shut the motor off.

after that it should just sit there like that doing nothing at all until you press the brake pedal 2 or maybe 3 times. Then it should run again for a few seconds, click, and stop.

if it runs continuously, runs repeatedly with no pedal use, or never runs at all. something is wrong.....

Ok sounds good I will try it now..I was wondering if anyone knows what the hole in the pressure sensor is for? There is a like 1?8" hole with a black plug..See pic

 

[billygeg]

it might run but it might be weak, or the check valve might be leaking.

put the switch back in and re-connect it. turn the key on (engine off) and watch / listen. The pump should run and build pressure for around 15-20 seconds, and then the switch should click once and the shut the motor off.

after that it should just sit there like that doing nothing at all until you press the brake pedal 2 or maybe 3 times. Then it should run again for a few seconds, click, and stop.

if it runs continuously, runs repeatedly with no pedal use, or never runs at all. something is wrong.....

Ok, I just put the pressure sensor back in, turned the key on and I heard the pump for the 1st time..It ran for about 10 seconds, I heard a click and it stopped..I depressurized the unit by pumping the brake 20 times while the car was off and turned the key on again, Pump ran again for about 7-8 seconds and stopped..I got in the car and the brakes feel normal even after pressing them about 10 times, they didnt get hard.. Is it possible the connections on the pressure sensor were dirty? Because I really did nothing but clean the terminals..It seems ok right now but the real test will be tomorrow when I take it for spin....

 

[BEATAV8]

Check it again in the same manner after driving it and warming it up for 20 minutes or so. Sometimes after warming up the unit will misbehave.

 

[billygeg]

Check it again in the same manner after driving it and warming it up for 20 minutes or so. Sometimes after warming up the unit will misbehave.

Ok will drive it around a bit tomorrow..Thanks for the help!

 

[wb_7354]

When my pressure switch went bad the brake light came on. I believe I bought a new one from rock auto. Problem fixed.


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