No brake fluid at the caliper?
 

Hi guys, have a bit of an issue, there is no brake fluid coming to passenger rear caliper? All other calipers are fine but that? Any ideas? Pedal is right to the floor. W plate. :angry2:

What were you doing to discover this? Maintenance of some description, or no braking force from that corner?

Had both calipers off as handbrake mechanism was seized. Rebuilt, put all back together and bled the system, pedal was a little spongy but passed MOT. Came home and decided to bleed it again, some fluid came out and then just nothing, pedal went to the floor. First thought was caliper blocked, but nothing is coming out of copper line that goes into the flexi.

Does the front right bleed ok and have plenty of force?

All other calipers I can bleed with pressure bleeder, but pedal is right on the floor, very very light. There is some force (very little) at the very end of the pedal.

Just double checked and FR caliper ain't bleeding either.

Puzzling. Diagonally opposed calipers not working are a sign of a bad master cylinder. That can often happen when bleeding with the pedal on cars that haven't had regular fluid changes as the moisture absorbed in the brake fluid corrodes the inside of the master cylinder. Its fine while the brakes are operating normally, but when the pedal is pushed past its normal position when bleeding, the corrosion trashes the seals and you lose one or both circuits.

What's odd is that you're getting no fluid with a pressure bleeder either. Are you using at least 2 bar on it? You need that to get through the ABS pump.

Been using about 10 psi, scared to pop the container? :Confused:

Like i said, pedal is very soft, but i can still stop the car when pushing it right in the floor? Surely if master is gone there would be no brakes at all? :Confused:

That is the exact symptoms of when I had a master cylinder fail due to the scenario I described. One circuit (ie one half of the master cylinder) failed so I had no brakes on FR and RL (or vice versa) and then once the pedal had almost reached the end of its travel, it braked on the other two wheels.

The brake fluid reservoir will take 2 bar if its not cracked or damaged. It'll expand quite alarmingly, but I haven't had a D2 one pop yet! You'll not push fluid through the ABS pump at 10psi.

Diagonally opposed cylinders linked are part of the standard design of braking systems to ensure total failure is extremely unlikely. And have been for decades.

So the symptoms are to be expected from almost any braking system going wrong, the challenge is to work out exactly what the cause is.