Brakes question

[mudpup]

Alright I got f/r dana 44's from a waggy, for some reason I keep getting air in my rear brakes. So far the brakes on the rear are as they came except I replaced wheel cylinders on both sides. (the front brakes are working great this is only a problem in the rear) Any ideas of what keeps allowing air in the brake lines. All the brake fittings look good and show no signs of leaking, the resevoir also stays the same leveel. At this point I have bled the brakes several times, on 2 seperate occasions I had very tight brakes after bleeding(good thing), then after a couple days the brakes slowly decrease pressure and gets to a point where I have to pump the brakes.
Just looking for some ideas as to what is causing this?

[Scott Hill]

do you actually get air to come out when you bleed them??

I have the same problem with my 61 wagon but there is NO air in the line anywhere so I can figure that one out.

I would check the cylendar spring and make sure it is keeping tension and not backing off and what you are doing is refilling the cyl. from them being compressed.

neaxt would be look and make sure the new cyl. are good and dont have a bad inside seal.

[mrblaine]

I have not been ignoring you. Just running options through my head.

I was originally thinking bad master, but the symptoms of that would be consistent.

It sound to me as if you have a bad residual pressure valve in the combo block and the shoe springs are eventually overcoming it.

The residual valve is supposed to hold the shoes out near the drum so when the brakes are applied, they have less distance to move to contact the drum.

Not sure how to diagnose this, but it seems that you should be able to pump them back out with the brake pedal and they should hold for awhile.

[Scott Hill]

Blaine,

any idea what it could be with the same symtoms on non-power brakes that have no springs to pull them away from drum.


it is driving me nuts but all I have to due is pump 2 times when I first gety in and is good for the rest of the day. I never thought about the MC do you think it is worth a rebuild??

[mudpup]

yes, air does keep coming out when I bleed them. Its like I bleed the air out then a week later there is more air.

I'll do some more checking on the stuff blaine mentioned, but thats gonna have to wait till I figure out how I broke my lockrite.

[underDAWG]

Originally posted by Scott Hill
Blaine,

any idea what it could be with the same symtoms on non-power brakes that have no springs to pull them away from drum.


it is driving me nuts but all I have to due is pump 2 times when I first gety in and is good for the rest of the day. I never thought about the MC do you think it is worth a rebuild??

OK... I did my search

Scott, have you find out where is your brake problem. Your is similar to mine. If I drive my TJ everyday, my brake is OK, not great. If I leave it on the garage for a few days, it has no brake untill I pump a few rapid strokes. I bleed and bleed, it still the same.

Later,