Quote:
Originally Posted by maxwedge
The combo valve should have a " button" on the end, maybe covered by a small rubber bellows, hold the valve out with maybe needle nose pliers ( moves about 1/8"), this opens the flow to the rear brakes.
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It does have a button, it is smooth, no grooves or any features. Many posts I've seen on several forums say it must be held "in" to permit bleeding of the rear brakes. Some others say to pull it outward to do the same. But all of them say that button will not re-center the valve, it will only "temporarily" allow bleeding (fluid flow) to the rear brakes. (Or fronts, depending on which side of system the valve sensed a leak/low pressure and blocked off).
I tried pushing it in, and pulling it out with Channel-Lock pliers. It does not move in either direction. I don't know if it is frozen, but the old fluid I drained from the Master Cyl and calipers/wheel cylinders did not look bad - it was yellow-ish, but not rusty or dark. (I replaced all of the same parts 14 years ago, and it has not had many "miles" put on it - car is used only for bracket/drag racing).
This afternoon I may try the method listed in my original post - Open front bleeders and stab the pedal. This would theoretically create less pressure in the front system than the rear, (the combo valve would sense the pressure difference, and interpret this as a "failure" in the front side), so it would move the shuttle valve to block that side, thereby opening the rear side to flow from the M.C.)
If I could get this to happen, I could gravity fill the rear side, bleed it, then re-bleed the fronts. When all corners are properly bled, supposedly one hard stomp on the brakes will recenter the valve...
Again, any comments will be welcomed.
