Brake problems--maybe

[Rick Yeager]

This is an odd problem and unfortunately, I cannot be accurate in describing it. The poor car has about 70 stormy miles on it. One of the problems that I have not been able to resolve is that intermittently the car will not roll freely and resistance against the engine goes up dramatically. It will get so tight that the car will not go downhill without the clutch engaged. We think it is the brakes and are not sure that it is front or back or both. Although I guess it could be the differential. One of the things that makes it so difficult is that the problem may come and go seemingly spontaneously. It began after the car had been sitting for a long time while I was attempting my first-time body work. When we tried to push it out of the garage the brakes started becoming very tight and the car would hardly move. We stopped to rest with the back of the car pointed down hill and suddenly the car started rolling down hill freely. When the car is on the road, it generally starts out fine then gradually gets tighter and tighter and then may gradually free up. Also the intensity of the tightness may very. Stopping and backing up may make it better sometimes but not always. The brake pedaly may become very hard and hardly move at all with pressure. Also the car bucks and jerks dramatically anytime I try to back it up under power but seems to roll freely when pushed by hand. At first we thought the bucking was because the clutch had sat unused for so long but now I wonder if it is not part of the brake problem. This jerking does not seem to occur with the forward gears even when the brakes are fairly tight. Part of the problem for me to identify it or even to describe it to you is that it is frequent but not constant.

The master cylinders are the twin system with the balance bar from Shell Valley that have been out for years. The front brakes are the older Mustang II conversion ECI system which uses the 11’ Granada rotors and the GM calipers and the rear brakes are a drum system that came with the 9’ axle housing from a 1974 Mercury Montego MX. The front calipers and the rear slave cylinders have been replaced with new rebuilt units by a competent mechanic. (Obviously not me ). This did not change the problem. The emergency brake cables have been loosened to the point that they are not functional. I do not have residual pressure valves on either system. It does not have a hydraulic brake lock sysem.

I am to the point that I am thinking of asking a friend to follow me in his truck. When it occurs just pull over to the side of the road and jack it up to see if I can find something. Would any of you all have any ideas about the cause or what practical diagnostic steps I might take?

I thank you in advance for any thoughts.

Rick