Ron Peterson writes >
> I've determined that one of my front disc brake calipers on my '77 MGB
> is sticking occasionally, particularly in cold weather. When I brake,
> the car pulls to the right until I press further and the piston breaks
> free (often with a loud clunk) and grabs the disk. I know it's not the
> back brakes because when I apply the handbrake the car keeps going in a
> straight line.
IMHO, you know nothing of the sort. The mechanism for the parking brake
is mechanical, and does not rely on the hydraulic piston. So, if the
left rear brake was doing this, the parking brakes would still work normally.
That said, it may be the front brakes. If you feel a sharp pull in the
steering wheel when you stab the brakes, I would suspect the front brakes.
If the car pulls to the right, but you don't feel the wheel fight you, I
would suspect the rear brakes.
> So which caliper is it? With only one brake grabbing in
> the front, which side is it that makes the car go to the right? It
> seems to me that it would be the right brake that is working ok, but I'd
> like to hear from the voice of experience before I order a rebuilt caliper.
Presumably the problem is with the left-side brake, whether front or rear.
The best way to approach this is not with road testing, though. Get the
car up on jackstands. Have an accomplice sit in the driver seat and
follow your directions in operating the brake pedal whilst you go from
wheel to wheel and rotate each by hand to feel what is going on. If for
instance, you find a certain pedal pressure whereat three of the wheels
are braking and one is not, you are close to an answer. If increasing
pressure brings a CLUNK and the wheel locks, you know your original
hypothesis is correct, and which wheel is to blame. If you can get the
effect to repeat, you will be sure.
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