1970 S2 E-type 4.2 2+2 clutch master cylinder

[ChipChipChipper]

So I’ve another head banger. I have serviced the clutch master cylinder which is a Girling with the body stamped
308601 CC2. (Might just be the casting number.)

The push rod that is fixed to the clutch pedal doesn’t seem to have anything to attach the other end to the piston. In other words the push rod can push the piston long the bore of the cylinder, but cannot pull it back. Is this correct?

I cannot bleed and get the system to work. What pushes/pulls the piston back along the cylinder? I thought it may be the actual clutch pressure plate when the pedal is released but of course you can’t get that effect until the system is full of fluid and operational.

I’ve looked in my manuals, Jaguars parts catalogue, on the web, on spare part suppliers diagrams, they all show a different master cylinder.

Anyone, know if/how the pedal rod is attached to the cylinder piston?

Here’s a photo of it. Thanks very much

[mgcjag]

Hi Ian...you should have a long return spring inside the master cylinder as per the service manual diagram to push the piston out to the full pedal "off" position...Steve

[ChipChipChipper]

The spring is in there but doesn’t seem strong enough to return the piston so suspect that’s what needs replacing. Thanks very much Steve

[mgcjag]

There is a spring also in the pedal houseing to return the pedal....the one in the master cylinder is just to return the piston...Steve

[Joes66]

Yup there is
I just ordered one as mine had rusted away

https://www.sngbarratt.com/English/#/UK ... afe27934cc

[abowie]

The reason you're having trouble bleeding the system might be because you have the piston jammed down at the bottom of the cylinder. It might be easier if you pressure bled the system at first until you have it full of fluid, rather than pushing the pedal down to the floor.

Remember that it's not the MC spring or pedal or rods that make the piston come back out, it's the clutch spring pressure conducted back by the column of incompressible hydraulic fluid. What the spring probably actually does is holds the seal at the end of the MC against the filler hole so that its in it's in the correct place to stop the reservoir being pressurised when you put your foot on the clutch.

If you were still unsure about your spring you could buy a C27186* aftermarket unit from the usuals for £20 and put the guts into yours.