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Re: Brake Master Cylinder

PostPosted: Sat Mar 17, 2018 9:14 am
by Wevster
Hi All

A bit of an update on braking system so far, new m/c fitted, new front discs + pads (greenstuff) + shims/pins. New front bearings. Caliper pistons/seals and braided pipes all round done. Still running old discs and pads on rear.
Regarding the Girling mk11b servo, its definitely working but has never felt smooth in operation, too much travel on the pedal and then sharp braking. At speed in a controlled situation, if pedal pumped hard the car anchors up pretty quick and can be controlled without locking, but otherwise in general use always felt a bit sketchy. I've also noticed slight brake judder coming up through the steering wheel, not massive but worse than before, I put it down to the bearings, however they've been replaced!
So 2 days ago after bleeding the system for the umpteenth time with and without the engine running,
the brakes locked up. I released pressure via front caliper nipple and tried again, and again brakes locked on. So I'm back to where I started but with all new stuff. I've since disconnected the servo and running without, no lockups but obviously I have a harder pedal with requires more effort. So as suspected the servo's at fault. It's possible that' the seals are incorrect as Hawksfield has already suggested. Not sure whether to change for a lockheed unit. (fed up with Girling).
There's still slight brake judder, the servo appeared to accentuate it, this will require more investigation.
All suspension bushes/ball joints/trackrod ends/springs/dampers/anti rollbar rubbers are new and checked for tightness.
Haven't checked steering rack yet, any advice?
I've got a small leak coming from the radiator, so that will have to come out, giving me more access to to the rack, I have changed the rack mounting bushes and gaiters about a year ago,so they should be good, unless there is wear in the rack itself.
Any advice on the above appreciated.

Cheers

Kev

Re: Brake Master Cylinder

PostPosted: Sat Mar 17, 2018 2:38 pm
by Donels
Have you checked for run-out on the discs both front and rear?

Re: Brake Master Cylinder

PostPosted: Sat Mar 17, 2018 4:59 pm
by Wevster
No I haven?t, I do not have a dial gauge. Can it be done without, or is it time to buy one?

Cheers

Kev.

Re: Brake Master Cylinder

PostPosted: Sat Mar 17, 2018 5:33 pm
by Donels
I don't know of a way to check without one but Machine mart do a stand alone DTI for under ?20. You could probably lightly clamp it to the calipers etc without using a magnetic clamp.