Re: HOLY S#$%&T BRAKE FAILURE!

Posted by HH56 On 2014/12/23 14:27:24

Believe you have power brakes so did the brake pedal suddenly become rock hard and you really have to stand on it before something happens or did the pedal just go straight to the floor and no brakes?

Going rock hard could indicate a complete loss of vacuum assist but you still should have a bit of pedal and brakes. Going to the floor is the typical symptom when the compensator valve suddenly fails to close. Having it work again right after a failure usually indicates some kind of debris floating in fluid down inside the ram portion of cylinder which moved and lodged under the valve and prevented complete closure.

If the fluid did get all the way to the engine, it would indicate the vacuum canister portion had quite a bit of fluid inside it. Pushing the pedal down could have met the fluid and the resistance could have stopped pedal movement and brake application. It could have also forced fluid up high enough in the canister to reach an opening on the piston where the vacuum could suck it past the piston and into the vacuum valving and on to engine. That much fluid inside would mean a badly failed seal and the fluid reservoir should have been in need of constant refilling -- or with the drive home, almost empty by now.