poor brake feel

[gear_grinder]

hi

my brakes feel like they have air in them (soft and lots of pedal travel), however its only under vaccume when the engine is running. When not running the pedal feels firm and more normal (other then no vac assist). I'm keep thinking that i need to have the ABS unit bled out but idk. Ideas?

thanks!

 

[my pos mounty]

I would start with a good old fashioned brake fluid change first.
Bleed the brakes enough to get all the old stuff out and new stuff in. Then check out the pedal feel.

 

[gear_grinder]

i've done that already within the past year, i had a couple bits of hardline go on me.

 

[my pos mounty]

i've done that already within the past year, i had a couple bits of hardline go on me.

Then I suspect theres a problem with either the master cylinder (my first choice) or the Vac booster.

 

[gear_grinder]

how could you test it the master and the vac booster?

 

[2000LXS]

Get a vac bleeder $20 bucks at harbor freight my breaks have never been so good. Now a 1 man job.

 

[Gus Gorilla]

I've got a free test for you.
Turn off the engine and pump the pedal 20 times. This relieves any stored vacuum. Now firmly press and hold the pedal. If the pedal is high and hard (please refrain from "that's what she said" comments) then there is no air in the system, no leaks, and no internal bypassing. You would basically be dealing with "normal" at that point. If the pedal is spongy then there is air. If the pedal is firm but slowly sinks then you have bypassing in either the master cylinder or the ABS valves or possibly a leak you haven't found yet.
Go forth and pump yo brakes.

 

[gear_grinder]

K, i've done this b4 (to check for air) and its fine and takes less far less then 20 pumps. the pedal doesnt skink or feel spongie, very firm and solid (engine not runnning).