HI,THIS HASN'T HAPPENED BEFORE.I JUST CHANGED THE REAR PADS AND BRAKE CYLINDERS AND I CANNOT BLEED THE REAR BRAKES AS I GET NO FLOW THRU THE REAR LINES.A BRAKE SAFETY FEATURE I GUESS,WOULD THE PROPORTIONING VALVE BE THE PROBLEM AND IF IT IS HOW WOULD I RESET IT.THANKS

I had a bit of a dose with the rear cylinders. I had to pull off the resevoir top and open the bleed valve and pump and fill for a bit. Sometimes it is just a big air pocket, and you have to be patient.

COME ON SOMEONE MUST KNOW WHAT DIRECTION TO GO.TRIED AGAIN TODAY TO BLEED THE REAR BRAKES TODAY,CANNOT GET ANY FLUID TO RUN THRU THE REAR LINES.IS THIS BECAUSE THE PROPORTIONING VALVE HAS CLOSED THE REAR OUTPUT.HELP, MY WIFE NEEDS THE TRUCK.

get a second person. take lid off the res. start on passenger side wheel cyl. loosen the bleeder and have the second person push the pedal down slow and hold while you tighten the bleeder. repeat until no more air comes out. to keep it cleen you can use clear piece of 1/8 or 3/16 rubber hose and a soda bottle.Get a metal clothes hanger and wrap around bottle and put a hook on it. do not let the res. go empty.

It's fairly easy to determing if a closed-off proportioning valve is causing a condition where no fluid is coming out a rear bleeder valve when attempting to bleed the rear brakes.

Check the amount of pedal that you have when pressing the pedal down before starting to bleed the rears. Then open a rear bleeder valve. If the amount of pedal travel stays the saame, then either: (1)the proportioning valve has slammed to one end, preventing fluid from going to the rear brakes, or (2) the bleeder valve hole is badly clogged and not opening up.

On the other hand, if the pedal goes down further when the rear bleeder valve is open, then it's not a stuck proportioning valve.

If the pedal goes down a lot (like to the floor) with a rear bleeder valve open, and you're not pissing brake fluid out anywhere, then that indicates that you have a lot of air in the rear brake system, and you have to be patient to get it all out. If you have a rear drum brake system, after trying to bleed the rears for a while, take the drums off and be sure you're not pumping fluid through a leaking wheel cylinder.

I have a 89 Cherokee and over time a lot of crud gets into the brake fluid. If you're still having problems bleeding them, I would suggest clearing out all the brake lines with compressed air. I had a valve malfunction because of the crud but once all lines were blown out and reconnected, bleeding went without a problem.

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THANKS FOR THE INPUT, I DO BELIEVE THAT THE PROPORTIONING VALVE HAS TRIPPED,WOULD YOU KNOW HOW TO RESET IT?

REAR HOSE FROM HARD LINE TO TEE AT AXLE COLLAPSED OR GOT PLUGGED UP .EASIER FIX THAN I THOUGHT .THANKS

I'll bet that was a nice surprise! Usually, mine go the other way -- I think it's going to be a 15-minutes, $25 job, and it winds up being a 3-day $400 job! <img src="/forums/images/graemlins/lol.gif" alt="" />