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MG MGB Technical - Clutch slave cylinder

I've read on the BBS that bleeding the clutch system is difficult because the bleeder screw on the slave cylinder is below the point at which the hose attaches. This causes air to be trapped.

A solution I want help with is the suggestion to put the hose in the bleeder screw hole, and the bleeder screw in the hose hole. Are they really that interchangeable, i.e., are both threads the same and do both holes taper inb the same way so as to allow the bleed screw to close snugly? Also, does the hose manage to adopt a reasonable curve to the slave cylinder?

Thanks!
Daryl May

Daryl - There is an eaiser way to deal with traped air in the slave cylinder. After you blead the system in the normal manner push the rod, thus the piston all the way back into the cylinder. This will push any remaining air in the cylinder up into the line toward the master cylinder. Reblead using the normal method to expell the air in the line. You might have to repeat this two to three times, but it will get rid of all the air in the slave system. I even have to use this method on my Mazada truck. Good luck - Dave
David DuBois

Daryl, I had the same question about a week ago and got a great suggestion that made the clutch bleed a snap and a one man job. Get an old fashion oil gun, the type with the pump handle. Get clear plastic tubing, with an I.D. that will fit tightly on the oil can nozzel and the bleed nipple. Drain the clutch system, attach the tubing to the nozzel, fill the oil can with fluid, pump till the tubing is full and there is no air, then attach to the nipple. Push back the slave piston and hold it back with a C clamp lightly tightened. Take the cap off the master cylinder and pump until you see fluid filling the resevoir. Tighten the bleed screw, reconnect the slave to the transmission, pump the pedal a few times and you're in business.
BJ Denis

Thank you, Dave. Your procedure worked! Either that, or the coincidence that I did that and also raised the bleed screw above the hose entry point, and did those things shortly before the last air bubble would have exited the slave cylinder anyway! It took a heap of time.

BJ, I will save your plan for next time. Hopefully, that won't be anytime soon. I am not used to hydraulics bleeding being quite this painful.

In all the agro, I managed to try to close the hood while propped open, so creased it a bit. Grrrr!

The good part is that I went for a 10 mile spin afterwards, and got smiles from at least 2 ladies.

Thanks for your help.
Daryl May

Slave cylinders do seem to be shipped with the nipple in the wrong place and it should be changed over before fitting. But the biggest problem seems to be the relatively large bore pipe and loop above the MC. I filled the system from dry with a gunsons EeziBleed on very low pressure via the slave nipple, no more fiddling than that, and had full travel of the piston immediately.
Paul Hunt

This thread was discussed between 24/07/2003 and 25/07/2003

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