Bleeding a hydraulic throw out bearing?

[JustenGT8]

This Kent of a thing is giving me grief big time.

Spec twin plate clutch with a hydraulic throw out bearing (not due of brand). It shimmed up to fitting clearance perfectly. Both lines run nicely and the bleed line is nearly the perfect vertical orientation.

It's pumping fluid through the bleed line and can't seem to get any more air out.

But, not pressure at all? Even if the master cyl was too small ( and apparently not) it should still eventually pump up to get some pressure, but nada, nothing, zip

All I can think is that there is still a monster airlock in the throw out cylinder? Any special tricks to these things?

The car is a bit nose up but the bleed point should still be the highest point off the throw out.

It's an engine out job to access the hydraulic throw out so there will be tears if I need to do that again

[dnegative]

Crack it at the master, failing that, give it a pressure/vac bleed?

[JustenGT8]

Yeah cheers. Consensus is crack at the master cyl and/ or inject back up the bleed.

I'll try again in the morning....rellies here tonight.

[Javal]

I have had some troublesome Gen3/4 T56 slaves (concentric hydraulic slave) where you could bleed them as long as you like but still get no action. In the cases i've come across the problem has been that the throwout bearing is not actually contacting the pressure plate yet. Keep pumping the pedal with a sealed system, keep pumping and then pump some more. Little by little it should get the idea and crawl its way out to touch the pressure plate. Then you can bleed as normal. Royal pain in the penis when that happens.

[JustenGT8]

Nah that's not it in this case but thanks for the advice. Clearance spec is spot on but I can see the thing isn't moving at all, so still has air in the system.

[Tweak]

My advice is use a combo of holding a vac and pumping it at the same time.
Crack it were it connects to the slave and bleed it to the point and eliminate the master

[lexsmaz]

Years ago sometimes on the old Alfa's we had trouble bleeding the brakes etc & sometimes it worked if we kick bled them, as in leave the bleeder nipple open & stamp the clutch pedal as hard & as fast to the floor as you can & get someone to lock up the bleeder nipple before you come off the floor & then repeat the process ... Fingers crossed it might work for you too ..

Another option is to crack open the slave bleeder nipple & just let it gravity bleed, don't touch anything just keep the fluid up in the master cylinder reservoir ..

Also I would get the car as level as you can just in case the bleeder nipple orifice outlet inside the throw out bearing is maybe a bit more towards the back of the unit ??

[litldv8]

does the master have a remote reservoir?

[JustenGT8]

So I got the thing holding one pressure via reverse bleeding ( damn messy job that is ). It only has about 8mm throw though which isn't enough to fully disengage the clutch....I'm fearing the master cyl isn't large enough...curses

[JustenGT8]

As feared, seems MC is not big enough...At least i now know reverse bleeding of the new MC will get it sorted more quickly

[ra_28]

what size is your M/C?

[JustenGT8]

Current MC is 5/8 and i need a 3/4 at least. I picked up a FZJ80 Lanscruiser one and the thing is massive in comparison to the GTfour MC. I can get it to fit but it's going to take some work. I'm taking both into a good local brake shop to see if i can work out a more elegant solution.

[ra_28]

For my RA28 I upgraded to a NL Pajero 3/4 master cylinder, was a easy mod. They recommend either a 3/4 or 7/8 M/C to run the Howe bearing setup.

[Billzilla]

I might suggest finding a way to bleed it before putting the engine in next time.

[JustenGT8]

Next time! Fark that, getting too old for this shit