So I bleed my brakes and there is good pressure at the pedal until I turn on the engine. Then the pedal goes to floor with little resistance. I detach the Master cylinder from the Power booster and the pedal feels the same as when it's hooked up. Is my booster bad or do I need to bleed more? There are no leaks in any lines since M/C replacement. Also my idle changes when I hit the brakes. It didn't do that before. Thanks for any help

do you have a hairline cracked line somewhere? That happened to me. push out all the air...as soon as you have motor vacuum bam blows out some fluid. check under that leaky bastard for some new sludge :D

If that's not it take all the money parts off the truck then just set the truck a flame and run! collect inssurance and start over :D

Is the vacuum booster leaking?
Are you sure you got all the air out of the system?
If you have drum brakes, are they adjusted correctly?

i like Sillyneck's idea. None of my lines are leaking. The problem is that I removed the power booster thinking that was bad, but now I don't think that is the problem because normally when the booster isn't working (engine off) the pedal becomes very firm. I dunno

How does it drive, or stop i should say...?

The thing with the pedal "feeling" normal w/o the assist, well thats a given / normal... but it will not stop you... (W/O the assist that is)... one other last thing you could do, is take off the master cylendar from the booster, their will be a push rod, on the end of the rod is an adjuster screw/nut, play with it... I had a similar problem in my ranger, i did this and my pedal pressure was pack to normal...

try it

Originally posted by Stonyford
i like Sillyneck's idea. None of my lines are leaking. The problem is that I removed the power booster thinking that was bad, but now I don't think that is the problem because normally when the booster isn't working (engine off) the pedal becomes very firm. I dunno

i believe the cause or the idle change is a vaccume leak in the booster... because when you press all the way down it changes the vaccume pressure level in the engine, and drops the RPM. Mine does...

I doubt it has any cause to your pedal slop problem, because it would have the opposite effect, if it was toooo leaky it would not assist you at all, and the pedal would be ferm as if the booster was not working or connected.

Gracias
:beer: