how to: change the clutch master cylinder (U12)

[noss]

author - eurisko

[noss]

Simple enough repair, should only take about 20-30 minutes.

My Cylinder was leaking from the firewall, causing me to need to refill everyfew days.

What do you need?

New Clutch Cylinder.
Size 12 socket.
Size 10 open ended spanner.
Dremel or other metal cutting tool. (Angle grinder etc)
New Dot 4 brake/clutch fluid.
Small tube and container to bleed the clutch.

Firstly bleed the clutch fluid by turning the bleed screw ccw and pumping the clutch pedal. All the fluid should be pumped out.



Undo the pipe screw and 2 securing braket nuts.



Inside the car under the dash, at the top of the clutch pedal, there is a small pin and locking clip. Unclip and remove the pin. The clutch cylinder should be easily removed. (Second arrow in pic is showing the leak at the firewall)



Note the distance from the rubber stopper to the 'U' bracket on the original unit. Screw the aftermarket unit until its the same distance. Now, leaving an additional half a centimeter of thread, cut the remaining section of rod. This will interfere with the pedal travel, and prevent either complete engagement of the clutch, or prevent complete depression of the pedal. (I learnt this the hard way). Replace U bracket, and lock using nut.



Installation is reverse of removal. Refill fluid and bleed system untill clutch works properly.

You're done! Start engine, and test gear engagement. If fully depressed clutch, and still grinding or crunching, either there is air in your system (re-bleed) or adjustment is incorrect in the rod.

EDIT: To correct a mal-adjusted rod, untighten the lock nut behind the U bracket, and take it allllll the way towards the firewall (clockwise from our perspective) until it jams. Then, turn the rod by using the jammed rod to increase the distance . This will allow the clutch to fully disengage if it wasnt adjusted correctly. once thats sorted, retighten the nut. Make sure its tight, because it will shake itself loose, and you wont be able to change without crunching (which is what was happening to me today.... )

Enjoy!