Jim,

While the original rears were 7/8", all of the replacements, for many years have been 3/4", as far as I know.
I do know, that all of the ones that we sol, were 3/4".

Butch

If you are working with new wheel cylinders did you put the right size in?

Wheel Cyl - 1??? front 7/8??? rear

If they are not new/rebuilt that would be a good place to start looking, could be a stuck cylinder.

Jim...

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