Sweptline.ORG

This truck has been sitting for a while and three of the wheel cylinders were froze up. I replaced all the wheel cylinders and a section of line on the rear axle because it froze up at the flare nut. The fronts bled fine but I'm not getting any fluid to the rear. MC is full. (Dual MC). There is a prop valve or whatever its called mounted on the left frame rail. Are these known for clogging up? Or is there a special procedure for it like on some other cars? Any help you can give is greatly appreciated. Thanks.

71 D100 short bed, 383, 727, PS, PB, AC

Loosen the rear brake line at the master and see if you have pressure, with somebody pushing on the pedal but not too hard and don't let pedal go to floor. Then work you way down from there if it does.

The short rubber section of line from frame to rear axle is very likely plugged due to rubber deterioration and swelling closed internally. Rubber flex lines at front wheels are prone to this also.

Moving down the line is going to be the next step, except I might just start at the rear flex line. Ill be working on it again on Wednesday and Thursday. I replaced the front flex lines but not the rear... it looked ok externally but I know that isn't always the case. Ill let you know what we figure out. Just wanted to make sure there wasn't some common thing that was wrong that I may have been missing.

The flex line was the problem. But then I had issues with the axle brake line "T" or "Y" as some call it. There is no listing on any of the sweptline parts suppliers for this piece. So I found one for a similar year car with the same rear axle and it worked. The brake system is now done. Im now dealing with oil leaks and wiring. Thanks for the insight.

Go ahead and replace all rubber lines. Check that you are getting fluid from the front line on the master cylinder, that one should run the rear breaks, I would check them both for pressure, bleed the right rear first, then the left rear, then the right front, then left front, DO NOT PUMP THE PEDAL PREASURE UP, THIS ONLY INTRODUCES AIR BUBBLES INTO THE FLUID IN THE LINES. have someone push the pedal down, then loosen the bleeder, then close it and tell them to let it up, my commands are up and down when I tell them to. Be patient, of course, before starting this procedure, the brakes must be adjusted so you don't blow out a cup. KEEP AN EYE ON THE FLUID LEVEL IN THE MASTER CYLINDER. Always bleed the fartherest from the master cylinder first then closer and so on.