Brake problem driving me crazy!, UPDATE PG2!!!!!!!!!!!! Options

[Justin]

Ok, I recently decided to replace my master cylinder in my car because A. There was a lack of pedal pressure and B. I could not get any fluid to bleed out of the front right or left rear brakes. After I replaced the master cylinder with a reman I am still having the same problem. I made sure to reinstall all gaskets and O-rings, and to properly bleed the master cylinder before install. I have gone as far as removing the proportioning valve to make sure it still worked properly and it did and had no clogs. So as it sits right now I have good pressure to the front left and right rear brakes but no pressure to the right front or left rear brakes.

The master cylinder is providing pressure to the proportioning valve as proved by removing the line at the prop valve. I also sprayed all of the lines with windex and tried to find a leak but have not been able to find one. also checked the lines for any kinks but found nothing. Any ideas?

This post has been edited by Justin: May 6, 2007 - 12:58 AM

[Justin]

Dude, don't just throw parts at it.
Check the wheel cylinders.
It will be obvious if they are bad.
A slight bit of dampness IS ok.
If they are soaked, they are leaking.

How far out did you adjust them?
Ideally they should be adjusted out until you JUST hear the drum rub the shoes, then back off a notch or two.

Did you check/adjust the booster push rod to master cyl clearance?
There should be less than .5mm clearance.

The wheel cylinders are not even damp at all. I also adjusted them exactly the way you described. I havent checked the clearance between the booster push rod to the master cylinder yet. How would you go about doing that? It seems that as soon as you push the pedal down the brakes do start to hit the rotor so I dont know if that would be it. I looked up the part numbers for the GT calipers and ST calipers and they are different. And I think I may have gotten GT calipers when I replaced mine instead of ST calipers. Maybe the GT caliper takes more fluid to move the cylinders in them? I have had this problem after I changed the calipers but just assumed something else was wrong.

[toyotacrazy]

Dude, don't just throw parts at it.
Check the wheel cylinders.
It will be obvious if they are bad.
A slight bit of dampness IS ok.
If they are soaked, they are leaking.

How far out did you adjust them?
Ideally they should be adjusted out until you JUST hear the drum rub the shoes, then back off a notch or two.

Did you check/adjust the booster push rod to master cyl clearance?
There should be less than .5mm clearance.

The wheel cylinders are not even damp at all. I also adjusted them exactly the way you described. I havent checked the clearance between the booster push rod to the master cylinder yet. How would you go about doing that? It seems that as soon as you push the pedal down the brakes do start to hit the rotor so I dont know if that would be it. I looked up the part numbers for the GT calipers and ST calipers and they are different. And I think I may have gotten GT calipers when I replaced mine instead of ST calipers. Maybe the GT caliper takes more fluid to move the cylinders in them? I have had this problem after I changed the calipers but just assumed something else was wrong.

Are the caliper slides moving freely when you had it apart? Are both calipers holding when depressing the petel?

[Justin]

Are the caliper slides moving freely when you had it apart? Are both calipers holding when depressing the petel?

Yeah they are.