Blame painfully cheap Chinese crap FIRST.pdlrofdrms wrote:okay ready here is my rookie diagnosis:
Today I went purchased a new check valve intalled. And immediately it failed. I took a peek at it and there is oil in the vacuum line and now in the check valve allowing air flow both directions.
If a good check valve is installed in the wrong direction, it will give you no brake assist.pdlrofdrms wrote: Here is my theory. A few months ago I noticed when I depressed the brake pedal it made a wierd noise. But they work. I am thinking I must be crazy it must of always done that. I went back and forth and told myself you should check that out soon. I don't think its a normal noise.
I think what happened is the master cylinder was going bad, which in turn leaked into the brake booster, which then caused the booster to fail,
Boosters can fail because they feel like it.
pdlrofdrms wrote: I then install new check valve and no leak but no brakes either.
The pedal is hard to depress,
Is it possible to rebuild the brake booster?
And why is it called a servo on some sites?
A "servo" or "booster" (same deal) should only draw vacuum while you are moving the pedal p-e-d-a-l, then not draw any more vacuum if you hold the pedal stationary.
Start engine. Apply brakes with that p-e-d-a-l thingy. Shut off engine. Pedal should remain stationary. If it slowly pushes back up, it is leaking.
I rebuilt a brake booster once. Hair raising. Look in the Parts Known To Be Acceptable sticky in the Brakes Forum, and you should see a rebuilder listed.
If the master cylinder ius leaking brake fluid, yes, get a new one. The rubber o ring between the master cylinder and the servo/booster is a critical component for no vacuum leaks!
ColinYerDoin FINE