There has to be a proper relationship between the pedal mechanism, push rod, the master cylinder, and the booster.

There is a certain spot where the master cylinder piston has to relax after braking. If the piston is in the proper location, a bleed hole in the master cylinder is exposed allowing fluid to return from the system to the master cylinder reservoir.

Have you looked at the FAQ?

Have you done any work on these parts?

Do all the brakes drag?



I no longer have my 700 manual - In my 544 manual on the master cylinder, there is an illustration showing a mechanic inserting i slender rod (such as a paper clip) down the bleed hole at the bottom of the reservoir into a depression in the piston. This can be sensed as there is not much distance between the reservoir and the piston, more when the depression is in the proper place.

If this depression is not lined up properly with the bleed hole, the brake system cannot bleed off pressure and the heat and brake usage can build up pressure to drag the brakes.

When a mechanic installed a new booster in my "54 Chevy he did not set things right and my brakes (modern discs) got hot and dragged so much that the Chevy small block V-8 could not move the car!

He had to acquire a special tool to measure the proper set-up to get my brakes to work properly.

Ask how much a dealer would charge to set this straight