serious break help needed

[silverado13]

Alright so recently my rear differential completely collapsed inside my rearend and after a few weeks I finally found another 3.73 rearend but it was out of a 99 escalade. Same rearend just has bigger rear drums and a rear sway bar. This last weekend I swapped out the rear end and when I got everything together I noticed that I have hardly any breaks at all and the pedal has to go down about 75% before engaging any brakes what so ever. It's really mooshie. Also my parking brake like is stuck on in my dash. I bled the brakes and got most of the air out the lines. I read that it was most likely the master cylinder but from what I read. If I unbolt it from the brake booster then I should see fluid leak but its Sa dry as can be. Anyone ever have this problem or has any imput?

 

[96-1500]

I bled the brakes and got most of the air out the lines.

You need to do better than most of the air...you want to see clear fluid shooting out of the bleeder screws, no air at all. Go over all 4 several times and if you get any blurts (if that's a word, I don't think it is) of air, you need to keep going.
Did your master cylinder get really low at any time in the process?

Sounds really obvious, but I had quite a time getting all of the air out of the system on my truck. I think there was air up in the ABS module and possibly the master cylinder as well.

 

[DGA1]

Did you back out the shoes till they were barely dragging against the drums?

What do you mean unbolting the MC from the brake booster? The brake booster should not have any liquid in it. If you unbolt the rear brake line, from the MC and when you step on the brake pedal liquid will come out of it. If you see liquid coming out of the rear line at the brake cylinder keep pumping till you get a nice stream of bubble free fluid.

 

[silverado13]

At one point when I put it back together it did suck air from it going completely empty. And what I mean is they describes that when the master cylinder fails. It's the seals that fail so it was claiming that the seal betwen the brake.booster and master cylinder would have went bad and you'd see fluid there

 

[silverado13]

My main concern is what's keeping the emergency break light on. Some sites say that's a sign of a defective part

 

[Horns]

Pull on the park brake release cable and wiggle the peddle up. That may turn the light off.

-Sent from my twin turbo Desire using diesel fuel.-

 

[towman]

brake light is on because you have air in your brakes, bleed them again , same light works for brake failure and parking, if air in line the light will light

 

[96-1500]

Some people claim you need to bleed your master cylinder if it gets full of air. Mostly I thought that was just when installing a new one, but I guess if it runs dry it could be a problem. Perhaps somebody more knowledgeable could elaborate on that one.

I still think you've got air in the lines man.

 

[Swims350]

ok first up from what I've seen park brake and brake pressure light are 2 different ones correct?

if so like I'm thinking, having air in the system has NOTHING to do with a PAK BRAKE LIGHT, but the actual BRAKE light was on then yes THAT is why, air in the lines. or pressure problem between the front and rear.


So now,,,, did you bleed from the PS rear, then ds rear, then do ps front and ds front? Do them all regardless it's not going to hurt, it will just flush the system.

Some say oh no the front and rear are seperate no need to bleed the fronts if only the rear had problems, but not me I do them all anytime.

Old dirty fluid can ruin things in the system and cause rust to work faster on destroying things.


Now you could have a number of things wrong, could be a bad whel cylinder, could be the rear shoes are not adjusted out tight enough or close enough to the drums, that happened on mine. The shoes could be worn too much as well. If it was me, change both wheel cylinders, about $10 a piece, inspect the rear hard lines closely, if any rust change both, the parts store sells straight lines, flared with the correct ends(at least for my 88 anyways they we corect) then the one problem mine had which I had no clue of was the rear flex line, it let fluid out and I could blow thru it, but after changing EVERYTHING, MC, prop. valve, wheel cylinders, hard lines etc. I still had crap brakes, mine was the hose and one side not adjusted out enough.

Also the ear dump valve on the earlier RWAL trucks is a problem, it can be bypassed, the complete ABS ones I'm not sure about, then of course you come down to a MC, and prop. valve which very rarely goes out, but could need reset or held open.

IMO if your rear brakes were fine and didn't blow, the prop. valve should be fine, I think the newer 4WAL doesn't even have prop. valves.


So check the shoe thickness,

adjust them out

then if nothing else,

change both wheel cylinders or rebuild the ones you have,

inspect and maybe change hard lines(doubtful it's any problem but it'd help reduce risk or bursting later)

then change rear flex line, about $17 or so.

If NONE of that fixes it, I'd get a MC and try it.

 

[97PROSHOZ71]

Try changing the brake lines, I had this same problem on my truck and replaced the whole brake line system. Fixed it.