1968 MGC Clutch Master Cylinder Rebuild

In this video I will cover the steps to rebuild a Girling Clutch Master Cylinder using a rebuild kit. Rebuild kits are available from a number of different distributors and come with gaskets and dust boot to refresh the wear items on the master cylinder.

[@alaingiguere9197]

Instead of showing the dismantled master and backtracking, you should start with an assembled on and show how to remove the circlip and how you removed the piston. Thanks for posting!

[@TheBluetoo99]

A great help. Thanks

[@JRsGarage]

My pleasure.

[@bougsyboy1001]

You need to take any fittings from threaded end off, and slip on the dust cover over the tread, pushing it over the stem and washer would probably damage it.🙂

[@JRsGarage]

Thanks for the comment. Mine didn't have threads on the linkage. One end was the stem and washer and the other end was the "y" fork that connects to the brake pedal. Single piece. I think some aftermarket units are threaded but not mine.

[@scuba6663]

Thank you very much for this video!! Do you have a video of rebuilding the brake master cylinder for the same car? I would greatly appreciate it. Thank you.

[@JRsGarage]

No, sorry. When my brake MC died the metal actually cracked so I just replaced the whole thing vs rebuilding it. The concepts shown in the clutch video would be very similar though.

[@gasisthepastendoil]

Does anyone know why auto parts store masterclaw cylinders never work out?

[@JRsGarage]

Sorry, never heard of that brand.

[@Grandpasaab]

My clutch wont disengage fully, I noticed when I depress the clutch pedal the fluid in my resevouir lowers and when I release the pedal it raises again, does this mean my clutch master cylinder is bad?

[@JRsGarage]

I would guess it's not your master cylinder. When you depress the clutch pedal it uses fluid to press on the pressure plate to release the engagement of the clutch so that's normal for fluid to go down and then back up when you release it. Bleed the clutch first to make sure there is no air in the system, that could cause the issue you have. Then I would check your slave cylinder or the rubber hose that goes to the slave first. Those parts are fairly cheap and easy to replace.

[@Grandpasaab]

@@JRsGarage So when at a standstill in first gear with the pedal fully depressed and slowly revving the car creeps forward at about 6000rpm. About the level in the resevoir the clutch master cylinder becomes smaller and displaces the fluid to the slave right? I assume that when the clutch master cylinder is depressed the circuit is closed so fluid can only travel to the slave and not to the resevoir right? I've been stuck with this problem for 2 months now, it seems like the concentric slave is not going out enough to disengage the friction plate. But the slave does move out instantly when im depressing the clutch pedal.

[@JRsGarage]

How many miles on the clutch? It may just be worn out.

[@JRsGarage]

Yes, the piston in the master pushes fluid down the line and causes the slave piston to actuate and mechanically move the pivot arm that moves the release bearing to engage the clutch springs which cause the clutch friction material to disengage from the flywheel. Usually the friction material wears out first causing the clutch to slip more and more but worn out springs could cause the clutch to not disengage fully or it could be a worn release bearing or a bent pivot arm or damaged slave piston or worn slave cylinder that doesn't move the piston enough. Or could be air in the lines. Lots of possibilities.

[@Grandpasaab]

@@JRsGarage The flywheel, friciton plate, pressure plate, concentric slave + bearring have done just 2500miles in 2 months without any problem. I asked a fellow saab 9-3 rider to check if his fluid lowers when depressing the pedal and raises back when releasing the pedal, he said his level does not lower/raises.