Brake Pedal does not move!! Help!!

G

GN138

New Member
Joined
Jun 28, 2002
So, just a month or so ago I bled my Powermaster and the thing has been working great ever since.

Yesterday I'm going to work. The first 2 time sI stopped everything was cool. As I was getting ready to stop at the third light the brake pedal did not move and it took me a good 1/8th mile to stop from about 45-50mph. I had to stand on the pedal with both feet and pray that I wouldn't hit anyone.

The red "Brake" light is on.

Any ideas?
 
The Same thing happened to me, only I was going down hill and it took about 1/2 mile to stop!! The dealer replaced the pressure switch on top of the powermaster which "fixed" the Problem. The next day I converted to the vacuum system. The fact that the Powermaster could do this without warning meant I would never trust it again. That was 15+ years ago, and I haven't had a problem since. Just my opinion based on My Experiences.:cool:
 
My bet is that your accumulator is dying.
Red light in the dash is typically either parking brake or low pressure in the acc ball.
Run a diagnostic check: Brake System
 
Thanks! I replaced the acc ball about 30-50k ago so it may be time....

Thanks again, I will check your link too....
 
That being said, you may not be keeping good fluid in your PowerMaster. You have to change it every year or so. Kind of like your oil...it won't last forever. I have had the same acc for better than 50k and 6 years now. Still works just fine.

Before just throwing a new acc on it, check the diagnostics to confirm it. They are a little expensive these days.
 
I just completely bled the system and filled all new fluid over a month ago. Brakes have been AWESOME and strong, until they went out.
 
UPDATE:

So, the car sat at work from Monday morning (when the brakes went out) til late Thursday night when the roads were clear to drive it home. The brake pedal did not move at all on the trip home. The brake light stayed on and the brakes took a long time to stop the car. Drove it for about 10-15 minutes to get it home.

It sat all Friday and Sat cause it snowed. I went to look at it yesterday and the brakes worked perfect. i drove it around for about 5 minutes, stopping a lot and they worked fine.

I did the accumulator test and the motor ran for 5 seconds, which is a PASS.

I also did the powermaster test and it passed.

Any ideas?
 
Your acc pumped up in 5 seconds?!! Excellent!!

Ok, You may want to start looking for loose/bad wiring.

I will look up and find out how to test the switch.
 
Here's a weird addition to this issue:

My cam sensor is dead. It will let the car start but I have to unplug it to keep the car running. While cam sensor is unplugged do you think that could arc or cause some issues?
 
Got me. But anything is possible.
I would think the cam sensor would have to stay plugged in to keep the motor running. Timing of the injectors and all that.
:confused:
 
I have a new cam sensor (thanks to SoCal GN) but i just have to put it in and it snows on all of my available weekends.
 
Hydroboost Vs Vacuum Vs Powermaster

The Problem With The Powermasters Is Not Just The Accumulator, But The Hyd Pump. The Vanes Are Phenolic, And They Wear Out Pumping Brake Fluid Under High Pressure. Also, When The Seal Wears Out Between The Pump And The 12v Motor, Th Eelec Motor Fill Up With Brake Fluid, And Shorts It Out. That's When The Red Light Comes On And Stays On. The Accumulator Only Accumulates, Or "stores" The Pressure Built Up By The 12v Pump. The Car Will Stop (barely) On Just The 12v Pump Alone. When The Pump Shorts Out, It Keeps Popping The Fuse Or Circuit Breaker, And The Pedal Stays Hard. We Recommend The Hydroboost System, Which Runs Off Of The Power Steering Pump, Thus Requiring No 12v Pump, Nor Any Vacuum. Buick Decided Not To Use The Vacuum Power Brake On Their Super Car For Good Reason. Supercharging A Vacuum Booster Doesn't Work! They Need Vacuum! The Car Makers For Years Ground Their Camshafts Around The Need For The Vacuum Booster To Work, Regardless Of Performance. The Hydroboost Eliminates All Of Those Problems. Guys On This Forum Have Stated That They Can Pull 22lbs Of Boost With Their Foot On The Brake Pedal, And The Car Holds The Line. The H/b Is Reliable And Usually Lasts For 200,000 Miles. Even Then, They Still Work, But Can Leak When They Are Worn Or Have Had The P/s Fluid Run Hot. Other Than That They Will Outlast The Car. Check Out "powerbrakesonline.com" For Some Photos.
 
Went to drive it today since it drove fine all weekend and the pedal does not move, the PM motor does not run and the BRAKE light stays on.

I am in a pinch, need to fix the car to sell it and I bought the whole PM setup. We'll see if the accumulator is the issue tomorrow when I get the parts.
 
Light is on, low pressure in the P/M, motor isn't running to pump it up.

There isn't anything worng with your Acc ball or the cylinder portion of your P/M. You've proven that by testing it by the diagnostic procedure. At the worst, the problem is in the E/H motor...that pumps up the acc ball. I'll still bet on the wiring being a problem...as in a loose contact or broken wire somewhere. If the problem is indeed in the motor, you can just replace the motor. If you replace the entire P/M and the problem is in the wiring, you have wasted your time. See what i'm getting at?

If you don't know how to check the wiring, find someone who does. It may save you some time and money.
 
I'm pretty sure replacing the accumulator fixed it. I'm still not 100% because I need more time to drive it and we're supposed to get hammered with snow today, so the GN sat.

But, when I pulled off the old accumulator it felt like it rattled inside when I shook it.

Old accumulator, brake system pressurized, key off: depressed brakes 1 time and the pedal goes stiff.

New accumulator, brake system pressurized, key off: can depress brake pedal 5-10 times before the pedal goes stiff.

I'll update once I get more driving time and can confirm this isn't still an intermittent issue.
 
Glad to hear the Acc ball helped. Sounds like it is working right.

Even still, a fresh accumulator won't work if the motor can't pump it up.

Yes, definetely try again and make sure the motor is reliable. If it was just clicking on the old acc, it was probably deadheadding. The old acc diaphram was completely blown...that's what causes it.

Let me know....
 
Yeah, it's running perfectly now. The motors runs when it's supposed to, no brake light. All is well!

Thanks for all the help!!
 
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