850 Hydraulic clutch Issue

[Chuck W]

Well, here is a tasty tidbit.

Three failed attempts to bleed the clutch, getting some action but then losing it.

Finally I set it up to gravity bleed to try and get the air out. I noticed that the fluid level dropped very little, like 1.5-2 cm

A flash of inspiration. The clutch pickup tune extends well up into the reservoir so the brake master cylinder reservoir has to be full to overflowing to bleed the clutch. I was basically pushing fluid through until the tube sucked air, then destroying my bleed process.

Reverse bleeding should've solved that issue. (Unless this just was an after-the-fact epiphany).

[abscate]

Well, here is a tasty tidbit.

Three failed attempts to bleed the clutch, getting some action but then losing it.

Finally I set it up to gravity bleed to try and get the air out. I noticed that the fluid level dropped very little, like 1.5-2 cm

A flash of inspiration. The clutch pickup tune extends well up into the reservoir so the brake master cylinder reservoir has to be full to overflowing to bleed the clutch. I was basically pushing fluid through until the tube sucked air, then destroying my bleed process.

Reverse bleeding should've solved that issue. (Unless this just was an after-the-fact epiphany).

Indeed, Chuck, that’s the right way to do this. I was looking for a syringe or pump to do that while I gravity bled it, then noticed the reservoir stopped dropping consistently after 2 cm drop level. Epiphany indeed surfaced.

[scot850]

I am wary of reverse bleeding. A dealer did that on a 240 I had and first time I used the brakes on leaving the dealership there were none!! They had damaged the valve which was not designed to have reverse pressure on it. There is a reason you get all those suction bleeders and also the pressure bleeders. Not having fluid to get drawn into the system does make it a challenge! Good catch on that absacte!

Neil.