Sorry if this post should be somewhere else or I just didn’t see a related post but I have a 2005 Cooper S R53 that I just got and I am trying to replace the brake fluid. I started bleeding on the rear passenger and nothing came out. I pulled the caliper and nothing from the rubber line. I pulled the hardline from the coupling just behind the engine bay, nothing. I then went all the way to the ABS module and disconnected the line and guess what, nothing. All three of the other calipers bled just fine, no issues.

Anyone have any idea what I may be having to correct? Is it an air pocket? Bad ABS module?

 

Anyone have any input?

 

How did you bleed the brakes? Vacuum bleed, pressure bleed, gravity bleed, 2-man bleed?

What you describe is very unusual.

I have not looked that closely at my R53, but usually there are 2 lines from the brake master cylinder into the the ABS hydraulic pump unit and then 4 lines coming out of that for each wheel.

If what you are saying is correct, if you have a helper step on the brake pedal (entire brake system intact), you would not be able to rotate any wheel by hand except the passenger rear wheel. If that happens, then it would seem that yes, a valve in the ABS hydraulic unit would seem to be stuck and blocking brake fluid to that wheel.

I know some scan tools are able to perform an "ABS bleed" during which the valves in the hydraulic unit are activated in order to perform a complete brake system bleed - like when that hydraulic unit is replaced or disconnected, for example.

If a valve in the hydraulic unit were stuck, it seems there would be a fault code stored in it. Do you have any warning lights on?

 

Thank you for the reply ghostwrench. I used the two man bleed approach. What you're saying is correct, all three wheels(rear left, front right and front left) all lock up and the wheels do not spin. I was watching the caliper shift slightly under pressure. However the rear passenger has no movement under pressure and the entire brake line from the ABS module to the caliper is empty of fluid.
I currently have a Motive brake bleeder on the way so I was going to try that next. I wanted to try to get as much info with this before I broke down and bought the ABS actuator scan tool. I have a fairly expensive scan tool already that doesn't do the ABS test. I have no codes from the ABS system though.
I'm guessing the same thing you mentioned, a stuck valve for that line in the module. It's just a weird situation I've never seen before.

 

So does the wheel in question spin when you apply brake pressure? If not, and it won't spin without pressure either it sounds like the caliper is frozen...

 

If you get inpa. You can bleed you abs pump.

 

The wheel does spin when pressure is applied. The reason is the entire brake line from abs module to the caliper is completely empty of fluid. There is no visible signs of leaking and the entire line looks solid with no corrosion. That's what leads me to believe the problem is in the module. The caliper itself moves freely as I had to use the BMW rear brake tool to press it to change the pads and rotors. I just wanted some other opinions/experince to confirm or deny. I will be ordering an ABS scan tool this weekend and will report any further findings when i get it done.