Combination Valve

[Joe Mc]

I recall reading in the FSM that when bleeding after new MC install (I'm pretty sure it was listed along with new MC install steps) that there's a little rubber cover (seen in several pictures above) that you're supposed to remove. Have someone depress the brake pedal and you should see a little pin extend from where the rubber cover was. I believe the instructions mentioned (WTE) slide special tool #XYZ into slot of pin then bleed brakes as normal. Anyway, I didn't have the special tool and lightly grabbed the pin with the front teeth of a pair of vice grips (placed electrical tape on the teeth to prevent scaring the pin) and bled the brakes. I did purchase a power bleeder and although a bit of a pain, I've found it extremely helpful. Especially when you're working alone and no one to help with the "down", "hold it", "up" "DON'T TOUCH IT" routine.

Not sure if this will help but, you never know?

 

[bcbender]

Just stumbled on this one today,..

Not saying its your problem, but I had the same issue with rear brakes locking up on my Chevelle when I converted from Drum to Disc on the front....( I replaced the M/C and old style brake hold off valve with the conversion). I then did a second M/C.. same issue,... New stainless lines, no change, New Prop Valve. no change... New rear wheel cylinders as I thought "maybe there is corrosion inside"... no change.. Finally decided to change the rear shoes as a last ditch effort as really that was all there was left (they were new when the disc conversion was done a few years back not old). Whalla problem solved... It seems somehow they had become contaminated with "something" and simply putting a new set of shoes on took care of it. They did not appear to be anything on them, and visually looked new but would grab like the dickens.

I fought this issue for quite awhile and did not drive it on wet days or on gravel as it was almost undriveable forget about a panic stop...

JM2C don't rule out the simple things.

 

[Topzide]

Sometimes with brake shoes, you need to break the "glaze" on the surface and then re-seat them to the drums. Usually end up doing this every other year on the trailer brakes. Sometimes sooner depending on how much I've used it. As @bcbender said,"don't rule out the simple things".