How do I know when my hydrobooster is going bad?

[dremu]

I know, gets tattoos, piercings, hangs out with the wrong people.

Every now and again, maybe one time in twenty, the pedal goes waaaaay down for me to get a good stop. Next pedal pump is fine.

I am reasonably sure the brakes are very well bled -- pressure bleeder, lots of experience -- and I am pretty sure the power steering system is also bled well.

Would that behaviour be a reason to suspect the hydrobooster is on its way out? (It's used, a pull from the donor truck ... most of the rest of the system i,.e. box, pump, calipers, hoses, are new/rebuilt.)

-- A

 

[mudbog42]

Does it sound like a loud vacuum leak when your pedal goes to the floor and is it really hard to stop. Thats what mine did when it went out, just replaced it recently actually

 

[dremu]

Does it sound like a loud vacuum leak when your pedal goes to the floor and is it really hard to stop. Thats what mine did when it went out, just replaced it recently actually

A *hydrobooster* did that?

-- A

 

[JpEater]

Get it up to speed going down a hill and shut it off while coasting. Pump a couple of short strokes to releive the pressure and then try to stop. If the pedal is still spongy then you just eliminated the booster and know that there is a problem somewhere else.

 

[mudbog42]

A *hydrobooster* did that?

-- A

Sure did
Also you can check by pumping it with the truck off and it should build pressure to where you can't press it down anymore, hold it, then start the truck and it should fall to the floor or near it anyways. If it doesn't build pressure when the trucks off then its probably your booster.