94 S-10 Brakes Problem

[hanovt]

I just finished replacing the brakes all around, and a brake line going to the rear. There's disk brakes in the front and drum in the back.

I bled all the brakes but now the pedal doesn't get very hard no matter how many times i press the pedal and it seems like only the rear brakes are worked. I plan on trying to rebled the line, maybe there's still a lot of air, but I was thinking that it could be a master cylinder problem.

Also, the rear brakes are dragging like crazy, the truck won't even move when you arn't pressing the brake pedal. You can hear it grinding and when you get the brakes going, they start to smoke. I have the adjuster screws all the way down. Do you think it could just be the new shoes?

Thanks guys!

[old_master]

Originally Posted by hanovt

I just finished replacing the brakes all around, and a brake line going to the rear. There's disk brakes in the front and drum in the back.

I bled all the brakes but now the pedal doesn't get very hard no matter how many times i press the pedal and it seems like only the rear brakes are worked. I plan on trying to rebled the line, maybe there's still a lot of air, but I was thinking that it could be a master cylinder problem.

Also, the rear brakes are dragging like crazy, the truck won't even move when you arn't pressing the brake pedal. You can hear it grinding and when you get the brakes going, they start to smoke. I have the adjuster screws all the way down. Do you think it could just be the new shoes?

Thanks guys!

Does the red brake warning light on the dash work? If it does, is it illuminated when the engine is running? If so, the centering valve needs to be reset and the brakes bled. Try gravity bleeding first. Fill the master cylinder, open one rear bleeder and let it drip until there are no air bubles emerging from the bleeder screw. Close the bleeder and do the same thing with the other side. Do not let the master cylinder run out of fluid. Post your results back.

[hanovt]

The red brake light turns on when you fully compress the brake when it's running.

I will definitly do that tomorrow. Do I have to do something to reset that valve? Or will gravity bleeding fix it?

[old_master]

When all of the air is out, a quick jab on the brake pedal should re-center the valve and turn the light off.

[old_master]

As far as the rear brakes dragging: You will most likely find that a parking brake cable is not fully released. The cable has probably rusted to the housing and needs replacement.

[hanovt]

I tried the ggravity bleeding, it didn't change anything. I also inspected the parking brake cable and it seems to move freely.

When I go in reverese and stop it repeadedly it gets really tight and there is no grinding sound. But when i go forward there's a horrible grinding noise and the truck has trouble moving forward.

I'm thinking about replacing the master cylinder, but would that fix the grinding do you think?

[old_master]

After you are satisfied that only fluid runs out of the bleeders, with no air bubbles, tighten the bleeders and bleed the system normally. You may need to bleed the front brakes as well.

A little about self-adjusters: When the brakes are applied, the pistons in the wheel cylinders extend outward and move the tops of the shoes out to contact the drum. The bottoms of the shoes are kept in the proper position by the adjuster. IF THE SHOES ARE OUT OF ADJUSTMENT: When the brakes are applied moving forward, the shoes rotate slightly, (clockwise on the passenger side, and counterclockwise on the driverside). When the brakes are applied moving in reverse, the shoes rotate slightly in the opposite direction. When they rotate, the adjuster lever catches a tooth on the adjuster and tightens the adjuster. This is why/how the self-adjusting system cannot over adjust the shoes. When there is no rotational movement of the shoes in either direction, they are adjusted properly. Only the FIRST brake application in reverse can move the adjuster. After that, they need to be applied in forward to "reset" the shoes for the next attempt at adjustment. A quick "jab" on the pedal is all it takes, both in forward and reverse, to rotate the shoes and adjust them. If your brakes keep adjusting tighter and tighter, there’s a problem somewhere. The adjusters are not interchangeable side to side.

When new shoes are installed, the adjusters need to be adjusted. Something is keeping your shoes from fully retracting at the top. Did you replace all of the rear hardware, (springs and hold downs)? It should be replaced each time the shoes are replaced. There is a bar just below the wheel cylinders that fits in between the shoes. That bar moves the primary shoe outward when the parking brake is applied. Try temporarily removing the bar and see if that makes a difference with the dragging you're experiencing. If it does, the parking brake cable is slightly applied or out of adjustment.

The master cylinder will have no effect on the grinding noise.

[hanovt]

alright, sounds good. I replaced everything in the rear, all the springs and everything. I think that one of the pieces that catch the teeth, that is on the same piece as that which is the parking brake is bent outward and so it's not catching the teeth, that might be the problem. I'll try bending it in and if that doesn't work, i'll see if I can buy a new one.

I was thinking about the master cylinder because the brakes go to the ground and the front ones hardly have a pressure. (even though they get really tight when I reverse and jab)

My fluid is also very dirty. I figure for $30 I might as well replace the master cylinder and put in brand new fluid. I'm hopping that will allow the front brakes to start working better and for the pedal to not go to the floor.

Thanks again for you help, and I'll let you know.

[Chris Stewart]

I just put rear brakes on the little Cutlass and the shoe material was too thick and the drums wouldn't go back on even after I knocked the "outer edge" off the drum inside with my angle grinder. After sanding the shoe material with no real improvement, I ground about .030 off the caps on the fully turned in adjusters so the shoes could close a little more and they finally just did fit....good thing it wasn't Flat Rate...I'd starve to death.

[DelCoch]

Originally Posted by hanovt

. . . the rear brakes are dragging like crazy, the truck won't even move when you arn't pressing the brake pedal. You can hear it grinding and when you get the brakes going, they start to smoke. I have the adjuster screws all the way down. Do you think it could just be the new shoes?

I would have to say something is not right with the rear brakes components. Are the primary and secondary shoes on the proper side. Maybe the emergency brake needs to be adjusted to give it more slack. Compare the new shoes, adjusting star and other components against the old components and make sure they're all the same. I've seen new parts mislabeled and/or placed in the wrong packaging. Until you get the problem solved on the rear it won't do any good to replace the master cylinder. In fact, it may cause more porblems for you. The more things you tamper with, the harder it is to find the real problem.

[hanovt]

Well I found the problem; the parking brake cable was too tight, but i could not get it to give more slack. I turned down the nut on the main cable by the driver side door, but it would not give any slack in the drum, so I'm thinking that it is forzen up somewhere where it comes into the drum. So I disconnected it on one side and on the other I had to grind down the piece that goes across right under the cylinder. It still has some parking brake; enough static friction if you're on a hill.

But now the pedal still goes to the ground, and I can hear air come out of the master cylinder right under the resivoir where it feeds the front brakes. So I went and got a new cylinder and it was working; the brake pedal was getting harder w/ the truck running whenever we were bleeding. However we let it run dry by accident (I know, I'm an idiot). So we are having the same problem as before. I'm going to return this cylinder (advanced usually could care less) and stick it in. Hopefully this should be it.

Thanks guys.

[old_master]

The master cylinder MUST be bench bled before installing on the vehicle. Instructions come in the box with the master cylinder. Complete master cylinder bleeding can not be accomplished when the master cylinder is installed. After installing, do not allow it go empty while bleed each wheel.

Either the cable is rusted or the park brake pedal is not fully released. Grinding the equalizer bar may get you by for now, but when you find the real problem, and repair it, the park brake will not fully apply on the side that you ground down.

[hanovt]

Yea, I did bench bleed it before i put it in, it just got dry.

And I'm only fixing up this truck so my dad has something temporarly, so i'm not too worried about the parking brake long term...