It started last week when I heard a slight buzzing or an electrical short sound under the hood , but near the firewall. Kinda sounds like the buzzing of the ignition when the key is left in. I checked with the hood open and noticed every time I step on the brake I hear the noise as I apply the brake and it's coming from the area of the powermaster brake unit. Haven't honed in on it yet. If I keep my foot on the brake the buzzing does not keep going....just when I first apply the brake.......any ideas?......stilll working out the bugs a bit on this thing, but after sitting 8 years I expect it
Electrical buzzing from power brake unit?
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its turbo time
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Mine does the same when it gets cold out. If you top off your brake fluid it will go away.
Hi Glenn-
I hope you are back on the road again!
I had the same noise even with the fluid topped off. And while the brakes worked fine, I knew nothing about PowerMasters.
The previous owner told me it was a solenoid going bad and could cause total failure, so I decided to change to vacuum...on his recommendation.
Now, I don't know if he knew what he was talking about, so I will wait for more responses too.
Did topping the unit off stop the noise?
Steve
I hope you are back on the road again!
I had the same noise even with the fluid topped off. And while the brakes worked fine, I knew nothing about PowerMasters.
The previous owner told me it was a solenoid going bad and could cause total failure, so I decided to change to vacuum...on his recommendation.
Now, I don't know if he knew what he was talking about, so I will wait for more responses too.
Did topping the unit off stop the noise?
Steve
caseyviator
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- Oct 21, 2001
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new powermaster
have fun u will need a pm soon sucks
have fun u will need a pm soon sucks
TurboMonte 2
Car Nut
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This is typical of an accumulator ball going bad (losing pressure). Check with kirbansperformance.com for replacement (around $145?)--about the same it costs to convert to vacuum brakes!!!
You're going to be in for a fun-ride when your PowerDisaster brakes fail to Brake!
You're going to be in for a fun-ride when your PowerDisaster brakes fail to Brake!
83ttypecooled
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- Sep 14, 2003
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funny buzz
Hi,
It's typical that the infamous powermaster would give you trouble. It can't be helped;these systems are hopeless.I personally have a hydroboost setup on my G body, which I consider to be pretty superior ,but vacuum is OK too. My TTA seems to stop fine, even with the 1LE brakes it's got. Go to Vac.;it's cheaper.
Hi,
It's typical that the infamous powermaster would give you trouble. It can't be helped;these systems are hopeless.I personally have a hydroboost setup on my G body, which I consider to be pretty superior ,but vacuum is OK too. My TTA seems to stop fine, even with the 1LE brakes it's got. Go to Vac.;it's cheaper.
87we410877
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Yup mine did the same thing. But, now when you hit the brake the motor doesnt stop until the pedal hits the floor!!!!! Luckily i have an extra power master cylinder laying around. Will have to change it soon. Also, line lock doesnt work 
Yup mine did the same thing. But, now when you hit the brake the motor doesnt stop until the pedal hits the floor!!!!! Luckily i have an extra power master cylinder laying around. Will have to change it soon. Also, line lock doesnt work
If your pedal goes to the floor it has a leak at the master cylinder internally or one of the wheel cylinders or brake lines. The wheel cylinder or lines would be obvious. These would all be seperate from the powermaster including the internal leak. I replaced mine the other day beacuse of an internal leak. It actually started leaking out the back of the unit into the car! Only a few drops but the pedal was getting lower and lower and i could smell brake fluid in the car. The powermaster is easy to work on and its worth working on if you have accumulated enough spare parts like new sensors, accumulators, and pressure switches when they werre cheap. Remember switches were $25 and accumulators were $40? That was long ago, lol! New motors can still be purcahsed cheap and it is advisable to do so if you are going to keep the PM in your car. If the fluid stays clean the unit will last a lot longer.
87we410877
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Ok. I changed the PM today with one i had laying around. That one must be bad also. I didnt bleed the brakes yet but the pedal still goes to the floor and the motor runs like crazy. If i pump it up i will get a pedal for a second then the pressure drops of, motor runs and pedal is on the floor.
TurboMonte 2
Car Nut
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Don't Know How You Can Reasonably Test W/o Properly Bleeding Brake System First??
87we410877
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I dont know how the bleeding is going to work since the pedal is going all the way to the floor. No pressure is building in the system. I'll try it next weekend. I need a break or im going to put a screwdriver through the door.
If the pedal goes to the floor then it doesnt always mean theres no pressure. Probably air, which is very compressable. You will have pressure, but no hydraulic action. This is why you cant have any air in the brake system. Always bleed if you installed a new unit. No need to ad in a new potential problem. These problems you are having are not related to the powermaster part of the master cylinder. If the PM doesnt work and the brakes are properly bled and there is no leaks in the system, you will have a hard pedal. The pedal WILL NOT go to the floor though. If it goes to the floor it could be air in the system, external leak(s) (very obvious), or most likely an internal seal leak if you bleed the brakes and the pedal still goes to the floor. Its possible both units have bad seals internally. Theres a couple o-rings in them that often $hit the bed when they get old or are contaminated with dirty fluid.
87we410877
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I will try bleeding this week or weekend. Thanks alot.
Hi Glenn-
If you decide to convert to vacuum, here is the page reference on gnttype:
Brake System
I did not find the conversion difficult...just the usual unplug, then replug, bleed the system and they play. BTW, my PM went at 80K miles.
You will have to go to a wrecking yard to get the proper brake pedal unless you buy new. Also, you gotta have a little patience working with the pedal pivot bolt, under the dash...helps if you have skinny fingers and/or a longer-than-normal crescent wrench.
Listen, you got through the stalling problem, you will get through this too. It is just that the PM system is more complex than a vacuum system...so more can go wrong.
I know how you feel. Last month, I had three things (MAF, CPS, IAC) go bad at the same time. Today, the ECM just set an O2 sensor code [after an '06 Bentley Continental GT (4.6 sec., 552 HP, 198 MPH car) blew my doors off]. Yes, officer, visibility was 3/4 mile and no traffic. Hey, it's good to overreach one's grasp once in a while! Now I don't know if I like the new Aston Martins or Bentleys more.
Anyway, waking from my dream, our Buicks are old cars and fixing this breakdown stuff is to be expected before we get them stable.
Steve
If you decide to convert to vacuum, here is the page reference on gnttype:
Brake System
I did not find the conversion difficult...just the usual unplug, then replug, bleed the system and they play. BTW, my PM went at 80K miles.
You will have to go to a wrecking yard to get the proper brake pedal unless you buy new. Also, you gotta have a little patience working with the pedal pivot bolt, under the dash...helps if you have skinny fingers and/or a longer-than-normal crescent wrench.
Listen, you got through the stalling problem, you will get through this too. It is just that the PM system is more complex than a vacuum system...so more can go wrong.
I know how you feel. Last month, I had three things (MAF, CPS, IAC) go bad at the same time. Today, the ECM just set an O2 sensor code [after an '06 Bentley Continental GT (4.6 sec., 552 HP, 198 MPH car) blew my doors off]. Yes, officer, visibility was 3/4 mile and no traffic. Hey, it's good to overreach one's grasp once in a while! Now I don't know if I like the new Aston Martins or Bentleys more.
Anyway, waking from my dream, our Buicks are old cars and fixing this breakdown stuff is to be expected before we get them stable.
Steve
Hi Glenn-
I would say your choice.
My decision to go to vacuum was helped by a motorhome guru (20 years' experience) who asked me how many more things I would want to repair on the PM. It is electric and mechanical after all.
I just felt more comfortable knowing I can work on the vacuum system and, if it breaks down, I can get parts anywhere.
I got the proper pedal at the boneyard, the booster and master at Auto Zone.
I take vacuum from a plastic "T" off the top of the PCV valve (3/8" line).
The toughest part of my conversion was trying to get someone to push the pedal so I could bleed the brakes.
Steve
I would say your choice.
My decision to go to vacuum was helped by a motorhome guru (20 years' experience) who asked me how many more things I would want to repair on the PM. It is electric and mechanical after all.
I just felt more comfortable knowing I can work on the vacuum system and, if it breaks down, I can get parts anywhere.
I got the proper pedal at the boneyard, the booster and master at Auto Zone.
I take vacuum from a plastic "T" off the top of the PCV valve (3/8" line).
The toughest part of my conversion was trying to get someone to push the pedal so I could bleed the brakes.
Steve
Glenn,
Without actually putting my ear to it, you could have a bad motor or accumulator. Visit the Brakes page on GNTType.org and run the diagnostics procedure. If you still can't figure it out, I will be glad to help in any way I can. I have the full manual. Powermasters can be tricky, but they are actually quite simple.
Bison is correct, the Powermaster likes clean fluid. It also doesn't like to sit, it likes to be used. It has to be maintained well to work well. I rebuilt mine almost 6 years ago, keep good fluid in it and it has worked flawlessly ever since. Those who like the vaccum conversion can have them. I believe the powermaster to be superior to vaccum. No other brake system that I have seen can deliver upwards of 600psi in less than a fraction of a second. Vaccum has to build pressure from nothing when you hit the pedal.
PM me if you feel the need to discuss this directly. We can talk on the phone.
Without actually putting my ear to it, you could have a bad motor or accumulator. Visit the Brakes page on GNTType.org and run the diagnostics procedure. If you still can't figure it out, I will be glad to help in any way I can. I have the full manual. Powermasters can be tricky, but they are actually quite simple.
Bison is correct, the Powermaster likes clean fluid. It also doesn't like to sit, it likes to be used. It has to be maintained well to work well. I rebuilt mine almost 6 years ago, keep good fluid in it and it has worked flawlessly ever since. Those who like the vaccum conversion can have them. I believe the powermaster to be superior to vaccum. No other brake system that I have seen can deliver upwards of 600psi in less than a fraction of a second. Vaccum has to build pressure from nothing when you hit the pedal.
PM me if you feel the need to discuss this directly. We can talk on the phone.
Tom Tom Turbo
Turbo Goes Woo Woo
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I'm on my 3rd powermaster in 70K miles.....I can now change them out like NASCAR teams do pitstops!
These cars really test your mechanical abilities and patience
These cars really test your mechanical abilities and patience
