MR HYDROSEED

Okay great, Finally! Thank you for shedding some light. Correct, my truck does not have a rear height sensing valve, the proportioning valve that I was refering to was just below the master. I've stomped the heck out of the pedal several times just out of frustration from pumping and bleeding so many times, is that the only way to reset this thing? I've had so many problems with my brakes that that must be the problem. Is it the first manifold with a one wire sensor or the second one that has the harness? and what are both for? Thanks, thanks, thanks!

gmctd

The brake saftey switch\valve has the single wire, connected to the Brake warning indicator in the inst cluster - has a rubber cover over front end - pull the cover, see if the brass rod is protruding out = front brake leak

The lower valve with the multi-wire connector is the rear wheel antilock and saftey valve - rod out = rear brake leak - if either rod is out, valve is restricting flow to that axle set - if rod is in, centered, no saftey valving action is taking place

Master cylinder full, cover off, opening either\both wheel cylinder bleed should soon result in steady trickle of brake fluid - if not happening, could be the ABS solenoid block is plugged - crack the line-out to the rear brakes (trace the rear brake pipe along the driver's-side frame rail up to the block), see if fluid trickles out there - note: fluid will not drain when m\c cover is installed - if good trickle, may need to blow out the rear brake pipes with shop air - open both rear brake bleeds, let 'er rip.........

MR HYDROSEED

But, I just checked both valves. The front (top) valve, the brass pin was flush with the valve. The lower valve on the other hand, ah? There wasn't a pin? I took a center punch and it went into the hole at least 1.5", so now what? Thanks for the help regardless!

gmctd

Ok, that's correct - doin' this from memory, gettin' my GM and Dodge brakes mixed up - only way you can tell that saftey valve is tripped is with the ABS codes and brake indicator -

your ABS lite goes off after the engine starts?

the brake lite turns on with the emergency brake?

If rear braking is weak or non-existant, and you get no fluid when bleeding the rear cylinders, then the rear pipes are plugged or the safety valve is tripped or the RWAL block is faulty - that's the bottom one with the solenoids - won't give the brake warning if the rear is plugged up, requires a leak to trip the switch.

With engine running, everything normal, loosen the rear brake pipe at the RWAL block, step on the brakes - the ABS brake warning lite should come on, indicating a leak - if not, the RWAL block is defective - providing, of course, that you verified your brake warning indicators, as previously suggested

catnfool

just got back to this- SORRY!!! I ASSumed you meant the height sensing prop. valve... I hope you get your problem sorted out; garbage brakes are NO FUN! bruce