1990 chevy 1500 brake problems.

[BUCKYXJ]

Alright I have replaced everything related to the brakes and the rear still aint working. I can put a vise grip on the rear rubber line that goes to the t-fitting and the brakes work fine up front (perfect pedal pressure) but if I take it off then the pedal is very very low I have replaced pads, rear wheel cylinders (the drivers side didn't work the first time so maybe I got a bad one but problem is still the same.
I can push the rear wheel cylinder in on the drivers side like there is no pressure there, and the passanger side dont move at all when I push on it. HELP!!!

any thoughts? ideas?

[2000CAYukon]

I have a 90 K1500 and I am pretty sure the rears are the same. First off, you really need to adjust the rear brakes to get a good pedel. They are a pain to do because there is not an adjusting hole in the backing plate. You need to take the drum off, adjust a couple of clicks, test the drag. You should feel the drum drag or at least start to drag. If the drum is easy to turn, the brakes need adjusting.

Did you bleed the rear brakes? Are you getting fluid at both wheels? There is a rubber hose that goes from the rear to the frame. That could be bad causing the pedal to drop (it expands).

If you are not getting good pressure to the rears, the you need to look at the master and regulator.

//2000CAYukon

[BUCKYXJ]

Originally Posted by 2000CAYukon

I have a 90 K1500 and I am pretty sure the rears are the same. First off, you really need to adjust the rear brakes to get a good pedel. They are a pain to do because there is not an adjusting hole in the backing plate. You need to take the drum off, adjust a couple of clicks, test the drag. You should feel the drum drag or at least start to drag. If the drum is easy to turn, the brakes need adjusting.

Did you bleed the rear brakes? Are you getting fluid at both wheels? There is a rubber hose that goes from the rear to the frame. That could be bad causing the pedal to drop (it expands).

If you are not getting good pressure to the rears, the you need to look at the master and regulator.

//2000CAYukon

rear are adjusted maybe a little to tight just to make sure that wasnt the problem. and yes it sucked adjusting them.
rears are bled get good flow to both rear wheel cylinders.
the rubber hose if the one if I clamp off with vise grips I have perfect pedal pressure

[2000CAYukon]

Originally Posted by BUCKYXJ

rear are adjusted maybe a little to tight just to make sure that wasnt the problem. and yes it sucked adjusting them.
rears are bled get good flow to both rear wheel cylinders.
the rubber hose if the one if I clamp off with vise grips I have perfect pedal pressure

If you remove the vise grips, do the brakes grab on both sides? Jack up the rear and try to rotate the tires while someone is pressing the pedal.

Also make sure the rubber hose is not expanding while someone presses the pedal.

Since you get a good pedal when vise grips are applied, the problem has to be from the rubber hose back towards the rear brakes.

//2000CAYukon