Anyone have this problem?

[LBNJWE4]

Since I brought the car out of storage I have had a soft brake pedal and the brake light comes on in park. The car stops ok, but the light still comes on occasionally while stopping hard. My powermaster and accumulator work as they should. I bled the brakes today after gravity bleeding, the left rear had no fluid come out. I pumped and bled and the fluid came out as normal. Then I started it up and it was still the same only I noticed every time I stepped on the brake and the light came on, the dome light and clock dimmed. I noticed while driving the clock would dim in and out but never took notice if it was timed with my braking. Has anyone else experienced this?

 

[413turbo]

i've had that problem. bleeding my brakes until all the fluid had been replaced fixed it. i don't know if it had water in it or what, bleeding seemed to be a temp. fix. after 2 or 3 bleedings where all the fluid was new, i haven't had any problems. my car had been in storage for 10 years. so after a few stops the seals on the rear cylinders leaked, bad. haven't had any problems from the front. the brake unit is strange to me , how it works and all. but that's what i did, and it's worked so far, just replacing fliud.

 

[LBNJWE4]

thanks for the input, my car sat for exactly 10 years too! I will definitely give that a try.

 

[413turbo]

now understand, i don't know anything about brakes, except for how to change pads. but that seemed to work for me. and with the shoes off, i was playing with one of the cylinders and that's when the seal broke. the seal on the other one had exploded under boost for takeoff, 2 days eariler.

 

[83ttypecooled]

Hi,
If you are doing a rear brake job, as it sounds like you need to, use the larger, S10 truck,wheel cylinders.I think the big ones come on manual brake systems, so be sure to tell the parts guys that.
As far as your hydraulic issues are concerned,it is good you got the last of the old fluid out,because there is no more neglected stuff in our cars than brake fluid. Over time, like all else,it deteriorates. Regarding your brake warning light,the proportioning valve is stuck.It is on the frame, below the master cylinder.I am basically broke, so I disconnected the switch and I live with the slight bias towards the front brakes that this caused.Replace the unit, if you can.

 

[LBNJWE4]

thanks, will do that

 

[bmackinnon]

Hi,
If you are doing a rear brake job, as it sounds like you need to, use the larger, S10 truck,wheel cylinders.I think the big ones come on manual brake systems, so be sure to tell the parts guys that.
As far as your hydraulic issues are concerned,it is good you got the last of the old fluid out,because there is no more neglected stuff in our cars than brake fluid. Over time, like all else,it deteriorates. Regarding your brake warning light,the proportioning valve is stuck.It is on the frame, below the master cylinder.I am basically broke, so I disconnected the switch and I live with the slight bias towards the front brakes that this caused.Replace the unit, if you can.

Unless you race the car and need to powerbrake it alot, I wouldn't use the S-10 cylinders. It will effect the f/r brake bias, which GM put ALOT of engineering into for obvious safety/legal reasons. For a 99% street car, totally unnecessary, and in fact, unadvisable in my opinion.

If the prop. valve were stuck, the brake light would stay on all the time, especially under braking, and you would definitely notice a major problem in the braking performance. I'd bet the farm yours isn't.

Light's dimming when you hit the brakes is the PM motor energizing/running. It shouldn't run EVERY time you press the brakes. Not a very good sign, depending on 'how much' they are dimming. PM is possibly on the way out, requiring excessive current to run, causing the dimming situation. Suggest you visit Turbo Regal Web Site, and in their technical articles section, review the brake diagnosis charts/procedures, perform the tests that are outlined there to determine if a near future PM failure is likely.

Remember that if you do get the sudden 'hard pedal' unexpectedly, the brakes WILL still stop you, but will require a quick reaction with a 2 strong feet/legs.

My O2..... your mileage may vary...

 

[LBNJWE4]

My brake fluid is very foamy and yellow now, must have water in it. Would that cause the PM to run every time?

 

[zeus87gn]

FYI, that brake light is flashing because there is a problem with the brakes.
That what it is there for. DONT DRIVE YOUR CAR until you get it fixed or you will run into something stationary.....like a mustang or some other Ford.

What you are describing is the typical dying accumulator syndrome.
But, if your fluid is only frothy on one side, it could just be saturated with air.
Let the fluid sit a bit and see if it clears up.
If it does, cycle the accumulator a few more times until you don't see any more frothyness on pump down. Then time your system and you can determine how healty it is. Procedures are on GNTtype.org for timing, see link in my sig for cycling the accumulator.

Z

 

[bmackinnon]

FYI, that brake light is flashing because there is a problem with the brakes.
That what it is there for. DONT DRIVE YOUR CAR until you get it fixed or you will run into something stationary.....like a mustang or some other Ford.

What you are describing is the typical dying accumulator syndrome.
But, if your fluid is only frothy on one side, it could just be saturated with air.
Let the fluid sit a bit and see if it clears up.
If it does, cycle the accumulator a few more times until you don't see any more frothyness on pump down. Then time your system and you can determine how healty it is. Procedures are on GNTtype.org for timing, see link in my sig for cycling the accumulator.

Z

+1 !!!!!!!!!