QuestionQUESTION: I have a 1965 Chevrolet impala that i replaced the master cylinder today.for some OD reason i can not get the front brakes to bleed any fluid out.is there anything i might of messed.also how would i know if the break booster is bad.
thanks,
orlando
ANSWER: Did you bench bleed the master cylinder before you installed it? If not, you need to do it now. You can do it without taking it back out of the car - just follow the instructions that came with it.
If you already did that, and still the fronts won't bleed, and the backs do bleed, you either have a lot of air in the front lines or there is something blocking the fluid - probably bad front brake hoses.
You can't tell about the booster until after you get a good pedal by bleeding the brakes. Then, the way to tell is to start the engine and step on the brake pedal. If you hear hissing when you step on it, or if the engine speeds up when you step on the brakes, the booster is leaking vacuum. Also, of course, if it is good it makes the brakes much easier to stop with - much less foot pressure required for the same stop.
Dick
---------- FOLLOW-UP ----------
QUESTION: hey dick,thanks for the answer.i went ahead and put a new booster that came with a master and i started to get fluid out of my front.but now as i drove the car home from work it smoked real bad from the front.is it possible that i bleed it wrong,or now my pads could be sticking from the new booster doing its job?also i was told if i wanted it bleed right i could just loosing all the valves and let it sit for a few hours and it will bleed correctly on its own.whats your advice
thanks
orlando
AnswerIf the front wheels are getting so hot that they smoke, the linings must be dragging on the drums. This might be because the brakes are adjusted too tight (did you adjust them?) or because the master cylinder is applying the brakes even when you are not pressing on the pedal. It has nothing to do with bleeding the brakes.
If you haven't caused this by adjusting the brakes too tight, the problem must be that the master cylinder isn't releasing the pressure. What causes this is an incorrect adjustment of the push rod that goes from the brake pedal into the master cylinder. There should be about 1/2 inch of free motion of the pedal before the brakes start to apply. If this is set wrong, the pressure relief valve in the master cylinder will be blocked and pressure will build up in the brake lines from heat as soon as you start to drive. Since you have changed the booster, you might have to re-adjust the push rod so you have some free play in the pedal before the brakes apply. If you can't adjust this problem out of it, you may have been given the wrong booster or the wrong master cylinder for the car. If your car has been changed to disc brakes when it didn't have them to begin with, this could be the problem. I think you will probably have to take it to a professional brake shop to get it straightened out.
I can't help you any further with this, without looking at the car myself, and knowing all the history. With brakes, you're not going to have a safe car unless you get it to a pro and have him figure out what's wrong.
Sorry I can't be more help.
Dick
