Brake stiffness

[D-roq]

Hopefully its not too serious, but every once in awhile when i'm driving the brake pedal goes stiff then depresses with force. Could this be a vaccuum leak? If so should i check the booster first or a hose?

Thanks in advance for any advice.

 

[Gerdo]

I would bet that it is the brake check Valle. I have a thread somewhere. I'll try to find it later.

 

[D-roq]

I would bet that it is the brake check Valle. I have a thread somewhere. I'll try to find it later.

Ok so I found the thread and I'm almost positive it's the check valve as well, but the stealership did a vacuum test on the booster and said no air was getting in. Of course they wanted to sell me a brand new booster at $956.21 plus another $250 for labor.

Dgoll75 and I have come to the conclusion that if the booster were totally gone I would get no assist at all, I still get brakes once the vacuum in the booster returns to normal. I pulled the check valve last night and tried to do some mouth to mouth on it and found that it was like trying to suck a milkshake through a straw. I bought a dorman after-market (which doesn't fit fyi) and did the same test, wow what a difference. I had no problem getting air through.

I guess my question is am I right in thinking it is only the check valve?
Should the valve give a little resistence in letting the air through or not?