Handbrake

[tractor]

having just converted to disc brakes the handbrake wont work

with the callipers off if I pull the handbrake the cable pulls the cam to the stop on on the callipers but the piston does not move

does anybody know is the handbrake hydraulic or is it worked by a cam in the calliper if it is hydraulic then there must be air in it although the foot brake seems to work ok!!!!!!!!!!!!!!!!

[jaimo]

Did you wind the piston out to pads Chris

[tractor]

just took them apart and yes it is hydraulic and not on a cam so must be air in there the bleed nipple is at the bottom so have to see if I can back fill it under pressure

[Big Jim]

just took them apart and yes it is hydraulic and not on a cam so must be air in there the bleed nipple is at the bottom so have to see if I can back fill it under pressure

We are talking Sierra rear calipers here aren't we? if so, the caliper must be mounted wrong, the nipple should be on top.

 

Edited July 9, 2016 by Big Jim

[knights_templar]

if Sierra callipers, handbrake is mechanical, and on the Zero fitted up side down

[Guest 2b cruising]

Take the calipers off and put something solid to stop the pads closing in.

Turn it upside down to get the nipple on top and bleed them in that possition.

Then just put them back on.

Either vacuum or pressure bleeding can leave blind spots with air in if the outlet is lower than other parts.

[tractor]

now that's a good idea ken

virtual gold star awarded

Edited July 10, 2016 by tractor

[ozz]

Use an eezibleed air cannot get in or stay.

Edited July 10, 2016 by ozz

[tractor]

not got one ozz

but I do have a pumped weed killer tank which I will convert

[richyb66]

Eazibleed is good but it won't get trapped air out if the nipple isn't at the highest point.

 

Air rises in a fluid, there's no defying physics.

[Guest 2b cruising]

As said earlier.

Trapped air does not always get out if parts are higher than the nipple.

[Guest 2b cruising]

now that's a good idea ken

virtual gold star awarded

The rear swinging thingy's wil do fine instead of stars.

[ozz]

Eazibleed is good but it won't get trapped air out if the nipple isn't at the highest point.

 

Air rises in a fluid, there's no defying physics.

Trouble is i built the car and there is plenty of pipe work higher than the bleed nipple so eezibleed is the only way to purge the system that is commercially available that I found.

[ozz]

Air in a fluid under pressure is compressed heated and dissolves eezibleed does all of these things to any trapped air and then when the nipple is opened micro bubbles form and are expelled with the clean fluid being pushed through under pressure... Physics

[knights_templar]

forgive me if I haven't grasped something, but is it your handbrake not working, or/and your rear brakes in general?

 

Bleeding the rears on the Zero is a bit of a pain, and often needs bleeding, running and re bleeding, but bleed all you want and it will have no effect on the handbrake.