vacuum issue

[oldbill]

Help guys, must be an expert somewhere!
Brakes sieze if vac pipe is connect to servo.
This happens after about half a mile.

Brakes work (although heavy) when vac pipe removed from sevo.

Pads changed, new sliders, springs etc. Checked and rechecked, lubricated etc, etc.
Thought it was a knackered servo.
Servo changed, made no difference.

Is there a vac valve or breather valve that could be blocked.

Stumped & loosing the will.

Any realistic suggestions appreciated.

[blackie_2k5]

post some photos of the vac pipe youre running

and what do you mean by the brakes seize after half a mile

[oldbill]

The vac pipe I am taking about is the one that is connected to the servo.

The brakes sieze after about half a mile and about a dozen presses of the pedal.
Basically they do not appear to release and get very hot with the obvious stench of hot ferodo.

If I let them cool, take off the vac hose to the servo and repeat the journey they are fine.

[blackie_2k5]

ok..strange one..

it sounds like youre master cylinder might be fucked...did you replace that with the servo?

[oldbill]

Hydraulics ok without vaccum on servo. Servo only changed.