Picture 1: Right rear caliper outboard pad is not notably contacting and wiping the rotor "clean". Post wash water and general light rust building up and not getting cleared. It can be felt on top of the rotor surface with a finger. Picture 2: is the left rear and operating properly.

I first bled and it didn't solve the issue. This included bleeding the opposite side.

I then rebuilt the caliper and it's still happening. I again re-bled both sides for good measure.

It was mentioned in a FB forum I may have pad contamination, so today I swapped outboard pads side to side. Upon doing so, I noticed the right rear (problem side) slid right out; whereas, the left rear had to be forcefully removed. The right rear (problem side) inner had to be forcefully removed as well, so it tells me the inner is working just fine. The outboard side piston is extended from the rebuild fully pushed in position and touching the pad back but it seems there's a lack of pressure to force it against the rotor. I haven't drive it yet as it's not at my residence so I haven't tested the contamination theory; however, being the problem side pad was loose compared to the other 2 I pulled, I don't have confidence that's the problem.

The only thing I haven't done is to unplug the Electronic Brake Actuator; however, I've never done that when doing brake fluid bleeds in the past and never had an issue. Never seen anyone doing it on forums etc. in the past 10 years of ownership neither.

Pads and rotors have less than 10k miles on them.
Brake fluid is less than a year old, Castrol SFR.
Brakes lines to the caliper are braided stainless steel and not binding etc., OE right height.
Car has 103k miles on it, no leaks in the system and it's used as a street car only.

 

Caliper wound up being fine. Issue was Speed Bleeders are 2 threads shorter than OE for the rears! Swapped out for the OE bleed screws and outboard pad began contacting again. Speed Bleeder on the right in the pic.

 

Speed bleeders are not the answer to reliable brakes!

 

Can you please school the forum as to why? I'm very interested in your info.

Thanks for the insight!

 

Glad you got it figured out.
So, the speed bleeder was contantly in bleed mode?
Wasn't there brake fluid everywhere?

 

Speed bleeders have been around for decades, but haven't been universally adopted and used by racing teams. Why? For being such a clever idea, the one-way inner mechanism still can leak and so can the thread tooling for the speed bleeders themselves. Too many points of failure in such a small, but critical component makes it too risky to use. I'd rather use the OEM bleeders myself.