Bleeding Brakes

Q: Bleeding Brakes

I cannot get these breaks to blIeed on my 69. The car has factory power disc breaks. I had a problem with the power booster it had an air leak. The breaks worked fine you just had to push hard. I replace the booster and master cylinder with one I purchased from NPD. I bleed the breaks into canister with fluid in it I pumped several times on each wheel I also cracked the lines on the master cylinder but still the pedal goes to the floor any ideas

A: Did you “bench bleed” the master cylinder first?

A: If there are no leaks anywhere in the system, and you’re sure there is no air, the only other possibility is that the master cylinder is not right. You can test it by putting plugs in the holes for the brake lines (I thinks bleeders will fit) and pressing on the pedal. If it goes to the floor, the fluid is getting around the seals in the cylinder.

A: There is a button on the secondary delay valve under a rubber boot, it has to be held down during he whole process of bleeding. C-clamp, a wedge of wood, a door stopper something like that will work. It’s the valve that has a single in and out and is barrel shaped, not the distribution block.

A: Thanks a lot guys. I checked the master cylinder and even though it was new it was the problem. Put the old one back on wow I know how to bleed breaks again.

A: The shaft that protudes from the secondary metering valve (under the rubber cap)is often worn and corroded. Removing it, cleanin it up, or just messing with it will often cause the shaft to suck air when attempting to bleed the brakes. This valve is no longer available.

On my recent rebuild I had to replace the valve with the later edition “combination valve” for the disk front, drum rear. It can be purchased from Classic Performance.com or Year One for around $60. You will have to fabricate a bracket for it. Master Power Brake may be able to supply the valve with the bracket but they are spendy.

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