REAR BRAKE PUZZLE

I have a RR Corniche 1977.
The offside rear caliper started binding causing the brake disc to
overheat and cook up the rubber seals.Ive replaced pistons 4 and
rubbers but there is still pressure in the lower pistons when I use the
car.which is causing overheating again.
When the car is jacked up,if I apply the brakes without the engine
running the brakes come on and release normally,but if I apply the
brakes with the engine running the bottom pistons of the 4 bind on
,inother words there is pressure remaining in that circuit.If you then
undo the bleed screw the pressure is released.Can anyone help with some
suggestions
Roger

A severe blockage in the brake pipe perhaps. The servo pressure could be
enough to push past the blockage but the slave piston return springs are not
as powerful so the pressure is not easily released. Just a thought.


"supergun" <supergun DeleteThis @wanadoo.fr> wrote in message
news:1142510408.090490.159540@e56g2000cwe.googlegroups.com...
>I have a RR Corniche 1977.
> The offside rear caliper started binding causing the brake disc to
> overheat and cook up the rubber seals.Ive replaced pistons 4 and
> rubbers but there is still pressure in the lower pistons when I use the
> car.which is causing overheating again.
> When the car is jacked up,if I apply the brakes without the engine
> running the brakes come on and release normally,but if I apply the
> brakes with the engine running the bottom pistons of the 4 bind on
> ,inother words there is pressure remaining in that circuit.If you then
> undo the bleed screw the pressure is released.Can anyone help with some
> suggestions
> Roger
>