Clutch Trouble - Anyone with experiance of master cylinders...

cjpm

Having trouble with a car clutch, posted on motoring section but no responses. I know some guys here are pretty mechanically minded...


Spent the evening messing with a master cylinder for a Toyota Corolla

Problem - Clutch was not disengaging the drive, impossible to change gear once she warmed up. Decided to renew seals in the Master and Slave Cylinders. Despite the fact that there was no fluid leaking...... Should have known better....


Fitted seals, no problem. Bolted cylinders back onto car.

Tried to bleed it - no luck - No fluid exiting master cylinder and level in reservoir not dropping, even when hose disconnected.

Removed master cyl, and took reservoir off it. Noticed 2 holes on top of cylinder to let in fluid and the smaller one was blocked so cleaned it. Realised that was probably my problem all along as the cylinder probably wasn't getting enough fluid.


Put the cylinder back together and tried pouring some fluid into the reservior - working perfectly when i pumped the piston. Delighted to have figured it out, or so i thought...


Fitted it back into the car and low and behold, no fluid coming out of it again. Opened clevis pin on pedal and pumped it by hand. Fluid came out for the first 2 strokes and then no more!!!

Driving me crazy. I wonder are the seals too tight as when I press the cylinder, then cover the outlet, the piston only springs back to position when I release my thumb and let in some air. I would have thought that it would suck some fluid/air down from the reservoir instead....

pakalasa

I've changed both master and slave seal before on my David Brown tractor. I did them for both brakes and clutch. Assuming you put the seals in the right way, it probably down to bleeding.

Basically start at the reservoir and work you way down. Is the reservoir pipe going into the right hole on the Master Cyl? If so open the pipe slightly until the fluid drips out. Pump the pedal and you should get feel the fluid in the cylinder. Open all the connections one by one down along then untill all the air is out. There is a small nipple on the slave cylinder. This is the last bleed.

When doing a job like this, worth keeping a camera handy and photo everything as you take it apart.

cjpm

Seals are in the right way around and I've the Hayes manual too!! I can connect foot pump to outlet of master cylinder and bubbles run up through the reservoir. Then when I remove the pump, no fluid drips out!! Might have to give my mechanic a call!!

pakalasa

Keep at it. Bubbles up through the reservoir, you're on the right track.