Indulge me if you would, for a moment.

Before I preformed a full hydraulic flush, bleed, an fill with a power bleeder; I had thought about bleeding the clutch slave in the same manner (as the"one man brake bleed") I used to (brake) bleed my classic VWs:

1._After replacing the reservoir with a new one
2._After completely flushing/bleeding the brakes until the fluid ran crystal clear and refilling the reservoir
3._Pre-compressing the clutch slave before installation
4._Run a hose from the clutch slave bleeder valve into a container of fresh hydraulic/DOT4
5._Install the clutch slave and crack open the bleeder valve with the hose still attached and the end still submerged in DOT4
6._Slowly pump and release the clutch pedal several times until the components are completely absent of air.

Just a simple mock up to further illustrate my thought...

Your thoughts?
I am always open to enlightenment.
Thanks!

Edit: Yes I am aware that the slave is tilted downward in the mock up

Not sure that would work. Seems like without closing the bleed nipple each time before releasing the pedal, the suction would just pull the liquid and entrapped air bubbles right back up the line. Apologies in advance if I'm missing something; wouldn't be the first time.

(Edit: there is the often used 'trick' of elevating the front end of the car overnight with the clutch pedal pinned to the floor (like with a board placed between it and the front seat). That's to help get the rest or most of the remaining air bubbles out after you've tried but failed to bleed it out the old fashioned way. It does work - kind of, though not perfectly in my experience. The remaining air worked itself out after a few hours of subsequent driving.)

That said, there was another recent thread about using a hand pumped oil can to send the DOT4 backwards into the cylinder and up the line to the master. Naturally I can't find the NAM thread but here's the cited video, one of many on the subject, for a variety of cars it turns out, which can be found by searching on "reverse bleed:" I have not tried this so I do not know if it actually works on our cars.

I had to reverse bleed my e34iT slave, nothing else worked on it. Not even the over night thing.

what I do not like is those pressure bleeders that attach to the master res, much better option if you have shop air is the vacuum bleed where you pull fluid thru from caliper. it also has a reservoir that keeps the master topped off so you can literally pull totally new fluid at speed in one shot which will indeed get air out. Worked on the e46 and f31 which are notorious for getting air trapped in the ABS module with pressure bleeders or hand bleeding. Didn’t even have to activate it in inpa.


if you are using a pressure bleeder, or that’s all you have, do it instead from the bleed nipple up, just make sure you have turkey basted the res to make room for new fluid, and or have someone there to turkey baste it as it fills.

Thanks for this. When I changed the slave cylinder on this R53 the overnight thing *partially* worked; had about 60% pedal the night before, 75% the next morning. Enough to get on the road but still had issues going into gear and had to double pump the clutch most of the time. Not good. In the next several hours of open road driving - some of it involving hills - the air somehow worked itself out of the system and all shifting went back to normal. I really don't want to repeat that process in the future, so it's good to hear the reverse bleed method does work on at least one other BMW product.

And I don't even want to think about what kind of nightmare ensues trying to get air out of an ABS unit, which is why I haven't "flushed" my braking system to date although I know it should in theory be done every X number of miles.

If you have inpa, or similar, it’s no biggie.
Or if you have shop air for $20 buck buy a vacuum bleeder on eBay. That’s what I did for my f31 when I swapped out to bigger calipers and rotors all around.

if you were local I’d gladly help!