Had no time so I had the rears changed and the parking brake adjusted by the shop. Everything fine for at least a week and a half.

THEN...after sitting overnight it now feels as though there is almost no pedal on the first application of the brakes in reverse when pulling out of the driveway in the morning. WTF?

There IS pedal, just very low. Then after the first application (essentially a "pump") the pedal comes up to normal and STAYS that way. Even if I press and hold - hard - there is no drop in pedal height, full pedal, full braking, everything cool. Sounds like a bubble to me, but????

 

Vacuum booster?

 

Thanks Bob, but would that likely be a one time only per day problem? Just when I start it up in the morning? <img src="confused.gif" border="0">

 

Here's the method for testing the vacum booster from the guys at Pelican:

"with the engine stoped depress the pedel several time travel distance should not change

depress brake pedel and start engine pedel should move down a little

deprese the pedel and shut off the engine hold the pedel for 30 sec there should be no movement

start the engine run for about 1 min then depres the brake pedel several times travel should decrease with each aplication"

 

Okay, Adrial. Going out in it right now and I'll try it. But that last part doesn't seem to make sense. Why should I get decreasing pedal with the engine running after several depressions? Or is that if I DO have a problem? not if I don't?

 

Thats the behavior I noticed in my car...if I pump the pedal with the engine running travel gets shorter...actually...it was like that pretty bad before I replaced the MC/bled it...it doesn't do it as much now...I'll have to check that out.

I'm pretty sure it still does that though..

BTW that method was by a guy that posts to pelican, not pelican itself.

I'd like to see some other opinions on the subject...specifically reducing brake travel as you pump the pedal when the engine is running. There is an adjustment that can be made to the brake pedal regarding the vacum booster...procedure is in the factory manuals...maybe this needs to be adjusted??

 

Good stuff Adrial.

Dan: when your rear pads were replaced did they:

1 - bleed the system... especially the rear lines?
Remember, you have to push back the calipers to remove/replace pads. Since all the gunk in brake lines travels down hill to the calipers, and since brake fluid is hydrophilic (likes water and pulls it from the atmosphere), all the s%^&t in your brake lines collects in the calipers. When you push the calipers back, you shove that s#@t back up the lines and stir it all up. Water, brakeline grains, air. It all gets pushed around and up. That's one reason to bleed the lines after new pads. Pulls the s*#t out.

2 - replace the fluid in the entire system? The best you can expect from brake fluid in california is 2 years.... with or without tracking the car. Heat, dewpoint, salty air at the beach, daily temperature and barametric pressure changes... it all beats up on the brake fluid. Maybe a change out to the Super Blue might help. Those power bleeders work great, too. One man show!

My 2 cents - good luck. <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

 

Sounds like air in the system. You really have to bleed all our corners in the right order, even if you only replace a single caliper.