Brake issue
 

I have only been having this issue since about october and been trying a few things every now and then to get to go away.

Intermittently i have a very high and hard brake pedal. May not sound like a problem but. . . my pads are also relatively low and should not be that high or hard. I also every now and then will have the ASR, and ABS light come on forget exactly which lights all stability control related lights.
Does not matter if it is on the highway or street driving, nor hot or cold.

Also while the car is on the lift the front tires would harldy budge.

What i tried to do so far.

-I regreased the caliper pins, and the bracket itself.
-Pressed the caliper piston back to make sure it was not frozen. (did this a few times to make sure it wasn't that)
-I bought some stainless steel brake lines since i was afraid maybe some of the teflon lining in the brake hose was creating a flap and not alowing the fluid to retract holding pressure.

I have been thinking a possbile intermittenltly faulty abs block holding pressure on the front brakes or a failing master cylinder.

I have only seen a booster go bad once due to oil ruining the diaphram by traveling up the vacuum line on a BMW

Anybody ever have or see anything like this.

I had this happen to me. It was the brake booster. pedal was super hard and like I had manual brakes. no intermittent signs, just happened over night.

wheels being stuck would make me think more in a abs system problem though.

New fluid never hurts

I second the booster. Maybe replace the check valve on the front, see if that changes anything, sometimes they may get lodged, or contaminated, and prevent the engine from giving it vacuum.

Thinking out loud:

If the car's up on the lift (and I assume not running, therefore no manifold vacuum) then why would the booster be the main culprit; stopping the wheels from turning? Am I missing something?

I am thinking more of the ABS block acting like a poor man's line lock.

I was thinking the same thing, Bill. I would look at maybe the master being the issue. Could be the pushrod hanging up and maybe even causing a bad vacuum seal? I'd pop it out, look it over, and try reinstalling and retesting.

edit: Actually, get the brakes locked up on the lift, then disconnect the master and see if they remain locked up. You could also pump the pedal till its rock hard with the motor off, then start it with your foot on the pedal and see if it drops. That would rule out a bad booster.

it does drop when the motor starts, forgot to mention the car has had about 3-4 flushes over the past two years due to changing all calipers

but thanks for the other places to test, should be a few good places to look.

il update this once it stops snowing and i can get it in my shop next week.

brake booster or vacuum leak

booster might be my first check

I would hope this has been solved as it was over a year ago!

if its the booster i got one laying around im pretty shure. ill bring it to mikes.

You're a numbnut ^

It was the master. Yeah its been fixed.

As far as the and the faults were purely electrical undervoltage faults but have not coming on as frequently since.

Old threads again....yaaaaa

this is what happens when i only read the first post and then respond.