Brake system question.

Okay i have a 96 and while braking i only have half pedal. I bled em a while ago without much luck... What could be happing? MC failing?

So, #1, you make sure there are no signs of leakage. That means no use of brake fluid from the reservoir. And no wetness on the inside of the rear wheels, brake lines, etc. If there is leakage, fix that first. #2, start vehicle and pump up brakes about 5-10 times and hole down pedal hard. If it goes down steadily, your master cylinder is shot - replace. Only two things can make the pedal go down. External leaks or internal master cylinder leaks. If it holds, and you still need to pump the brakes to make them work, either your rear brakes are way out of adjustment or you have air in the lines.

Adjusting rear brakes: They are supposed to be self adjusting, but that shit freezes up quite a bit, and even after I fixed mine, it seemed like the original self adjusting cable was made too long to adjust properly. The best is to take all this stuff apart (pull the drums off and lube it all up including dia-assembling the adjuster star wheel). But, thru the slots, you can tighten up the free play in the rear brakes which could be taking up more fluid than the stroke of the master cyl can displace. If you never did it before, you probably need to pop off the rear drums and look at everthing.

Bleeding brakes: The best way is the GRAVITY method. The only problem is it takes a lot of beer and you don't want to drive right after. (CAUTION: YOU MUST BE 21 TO BLEED YOUR BRAKES THIS WAY!) I use it whenever I replace brake cylinders or calipers, but mostly it's just to change the brake fluid, which I do whenever I change shoes or pads. Ideally you change brake fluid at least every other year. If you worked on old cars and saw rusty pistons, you'd know why, but people also say that old brake fluid boils and won't stop you right.

1.) Get the car in a position where you can open up the bleeders. I always like to break them loose with a 6 point socket being careful not to break them off. If you can, spray them with breakaway or similar a day before.)
2) Starting with the bleeder futhest away from the master (pass. rear), open it about 1 turn. You can put a little hose and cup on it if you want to keep the old fluid from running all over. Make SURE to keep the master cylinder topped off with fluid and DON'T let it get down to where air gets back into the master cyl. Let it flow this way until the fluid comes out of the bleeder clean. This will take at least 2 cups or so of brake fluid. Using gravity alone, you can drink 2 beers while topping off the master cylinder for the first corner. (CAUTION: Do not store brake fluid in beer cans or put beer into master cyinder. Drinking a little brake fluid however will probably not kill you. Beer in your brake lines might.) Snug up bleeder good when you're done.
3.) Proceed to drivers rear and repeat. It won't take as long because the long brake line has already been purged of the old fluid. So you have to drink your beer faster.
4.) Pass front. Drink even faster.
5.) Drivers front. Etc.

Patience can be substituted for beers, but that's no fun.

This prevents the rubber pieces from going any further than they are used to and self destructing.

Hey thanks man. I adjusted them about a week ago but couldn't bleed them as i don't have any brake fluid right now. Ill have to bleed them tomorrow as i got a small jug. Again thanks for the long post.

winterbeater said:

So, #1, you make sure there are no signs of leakage. That means no use of brake fluid from the reservoir. And no wetness on the inside of the rear wheels, brake lines, etc. If there is leakage, fix that first. #2, start vehicle and pump up brakes about 5-10 times and hole down pedal hard. If it goes down steadily, your master cylinder is shot - replace. Only two things can make the pedal go down. External leaks or internal master cylinder leaks. If it holds, and you still need to pump the brakes to make them work, either your rear brakes are way out of adjustment or you have air in the lines.

Adjusting rear brakes: They are supposed to be self adjusting, but that shit freezes up quite a bit, and even after I fixed mine, it seemed like the original self adjusting cable was made too long to adjust properly. The best is to take all this stuff apart (pull the drums off and lube it all up including dia-assembling the adjuster star wheel). But, thru the slots, you can tighten up the free play in the rear brakes which could be taking up more fluid than the stroke of the master cyl can displace. If you never did it before, you probably need to pop off the rear drums and look at everthing.

Bleeding brakes: The best way is the GRAVITY method. The only problem is it takes a lot of beer and you don't want to drive right after. (CAUTION: YOU MUST BE 21 TO BLEED YOUR BRAKES THIS WAY!) I use it whenever I replace brake cylinders or calipers, but mostly it's just to change the brake fluid, which I do whenever I change shoes or pads. Ideally you change brake fluid at least every other year. If you worked on old cars and saw rusty pistons, you'd know why, but people also say that old brake fluid boils and won't stop you right.

1.) Get the car in a position where you can open up the bleeders. I always like to break them loose with a 6 point socket being careful not to break them off. If you can, spray them with breakaway or similar a day before.)
2) Starting with the bleeder futhest away from the master (pass. rear), open it about 1 turn. You can put a little hose and cup on it if you want to keep the old fluid from running all over. Make SURE to keep the master cylinder topped off with fluid and DON'T let it get down to where air gets back into the master cyl. Let it flow this way until the fluid comes out of the bleeder clean. This will take at least 2 cups or so of brake fluid. Using gravity alone, you can drink 2 beers while topping off the master cylinder for the first corner. (CAUTION: Do not store brake fluid in beer cans or put beer into master cyinder. Drinking a little brake fluid however will probably not kill you. Beer in your brake lines might.) Snug up bleeder good when you're done.
3.) Proceed to drivers rear and repeat. It won't take as long because the long brake line has already been purged of the old fluid. So you have to drink your beer faster.
4.) Pass front. Drink even faster.
5.) Drivers front. Etc.

Patience can be substituted for beers, but that's no fun.

This prevents the rubber pieces from going any further than they are used to and self destructing.

Click to expand...

:roflmao::roflmao:

That's the Best Write Up EVER!!!!!!!!!!!!!!!


I've been doing it wrong ALL these years.. I use a vacuum bleeder and no beer..


E

So a couple days ago I replaced the rotors, pads and calipers. I know that the MC and Vac pump is in good shape based on the test outlined above. Last night I used the gravity bleed method and did enjoy my time drinking beer but here is the problem.

It still feels like air is in the lines, it kinds sounds like it when the brake is pushed. With the truck off I can pump the brakes a few times and it will build pressure and stay in that position no matter how hard its pushed it doesnt come close to the floor. When I turn the truck on it goes straight to the floor. Very slowly i drove it on my driveway and it stops but the pedal literly has to be all the way down.

I am wondering if I maybe didnt tighten the bult connecting the caliper and brake lines tight enough? (or)

I dont think this would make a difference but is there suppossed to be a left and right caliper?

Any other ideas would be very heplful I am kinda stumped... Thanks

2001JeepXJNS said:

I dont think this would make a difference but is there suppossed to be a left and right caliper?

Any other ideas would be very heplful I am kinda stumped... Thanks

Click to expand...

Yes. If you have the caliper on the wrong wheels, then they are upside down.

The bleeder screw is supposed to be on the TOP of the caliper. If it's on the bottom, the air will never get to the bleeder to escape the brake line.

Really, it's been done more than once on this forum...and I'm talking about me.:roflmao:

Thanks for the help, that was exactly what the problem was!