Bleeding ABS - tiny bubbles that won't go away.

[Q451990]

I'm just wrapping up my brake job on Q2. Includes new pads, flex lines (Technafit SS), master cylinder, Stillen drilled rotors. Anyway, I installed new Speedbleeders in the calipers and ABS actuator. For some reason the front bleeder on the ABS won't come through completely bubble free. I still get some very small bubbles in there. None on the rear bleeder.

I haven't had the car running during the bleeding process, and the brake lines were open for 2-3 weeks during my leisurly re-install - so is it possible I got some air in the ABS unit that won't come out until it goes through a self-test or two? All of the calipers bleed fine, as well as the rear bleeder on the ABS. I've checked and re-checked for leaks. BTW - I've put about a gallon of fluid through the system.

Any suggestions?

Thanks!

Heath

[Q451990]

bump

[911/Q45]

I'll put in another pitch for the Griot's Garage vacuum bleeder. Maybe if you use it to pull fluid instead of pushing it, you'll clear the air. Is the pedal soft?

[Q451990]

Pedal seems really solid, but I haven't started the car yet - so no vacuum assist. Hopefully it's something that will bleed out with a couple of self-tests. Would it be safe to jump out the connection at the relay to run the actuator while having someone press the brake pedal? That would have the actuator functioning while it's being fed with fluid from the master cylinder... Just a thought.

Thanks!

Heath

[sijoko]

Have you bled the lines according to the sequence in the manual?

If you have, perhaps you are just pulling in some air from around the area where the hose and bleeder valve are joined.

When I bled the brakes, I say very small bubbles. They were introduced by the fact that the bleeder valve was loosened.

[reggiegsd]

As a rule, the brake pedal always feels hard with the engine off. Start the engine and then blead the brakes.

My experience is, once you get air into the Q brakes, you have to blead the crap out of them to get all of the air out.

Repeat after me, Push, Hold, Release.

[DAEDALUS]

I've had a bit of trouble with aftermarket bleeder valves allowing small amounts of air in from the threads after I loosened them up for bleeding. Did you make sure the threads were dry the entire time? If they're wet at all, air's probably getting in. I used some teflon tape and it seems to have worked.