Board logo

Hydraulic Handbrake
Alan G - 26/9/14 at 02:46 AM

Any advice on the best method to bleed a hydraulic handbrake?


Alan G - 26/9/14 at 03:01 AM

I have a bias pedal box feeding the good stuff to a pair of wilwoods up front and xr3i calipers on the rear.

After bleeding the full system using the trusty pedal pump method... I think there is still air in the rear system.

Does the handbrake need to be pulled as well as pushing on the pedal?


Alan G - 26/9/14 at 03:01 AM

Double post

[Edited on 26/9/14 by Alan G]


Ben_Copeland - 26/9/14 at 04:49 AM

Is it actually hydraulic or just cable operated calipers?

Check where the bleed nipples are on the rear. If they are facing down you'll have to take the calipers off.


Alan G - 26/9/14 at 04:57 AM

They are hydraulic... (car is not used on the road) and the bleed nipples are at the top. I do have a pedal feel and ehhh handle feel after I bled them however, it seems like I almost have to prime the handbrake by pushing on the pedal before pulling the 'wand'...

By doing this I get a much more 'solid' feel in the handle. I presume it should be the same solid when bled correctly?


adithorp - 26/9/14 at 06:48 AM

Have you got the handbrake operating on the same calipers? I thought it was normal to have a hydraulic h/brake operate a separate pair of spot. calipers (not too familiar with hydraulic h/brakes).

If it's on the same circuit and the master cylinder pistons are fully back (slight play in push rods as there should be) then doesn't that let the pressure escape into the reservoirs? That would explain why it feels different with the foot brake pressed.


Neb - 26/9/14 at 08:16 AM

The handbrake needs to be off (down) when bleeding. When open it is simply a object in the route of the fluid which is open. So you bleed as normal.

Sounds like you do have air lock there somewhere though, are the reservoirs lower than the handbrake? Making the handbrake the uppermost part of the system? If this is the case you may have to pump the handbrake when you open the rear nipples try evacuate the air in it.

I run hydraulic handbrakes in my cars for autotesting/autosolos. They are brilliant, when discussing the "bar" on TG Mr. Clarkson said something about women & orgasms i believe?

They can be easily plumbed into existing systems with a bit of thought but to satisfy the MOT man in theory you need a pair of cables too. Bike brake cables do the job and i drill small holes for the cables to pass through the backs of the pads which make them look like they are tightening but of course the hydraulic pressure is moving them.
Not recommended to leave a car sitting on a hill using a hydraulic handbrake though as we found out with a MK1 Escort in Wales when we cam back from the curry house and found it embedded in a brick wall (HB cylinders seals blew).
I remove the clevis pin and revert back to the standard cable set up for day to day work (106 rallye).


rj - 26/9/14 at 12:10 PM

always important to remember that air will rise to the highest point in the system, with no guarantee that normal bleeding will push the air to the bleed nipple, spent ages trying to bleed a brake system with a pressure switch mounted facing up, eventually unscrewed the switch to watch air bubble from the joint and then fluid.