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Fitted Brake master cylinder,Then came to fit clutch and found it did not fit ,I gather its a brake one , I bought this of good old ebay sold as a clutch new old stock, Question- Can it be turned around 45 degrees and is it compatable with clutch master cylinder or are they different ?????? I seem to remember they are soldered joints??????, This as been plated could the bottom base be un-soldered turned through 45 degrees ????, Or as someone got a clutch master cylinder new to swop ???
There are numbers on the bottom if that helps also a photo

Regards Goff

Those are two brake master cylinders. Clutch cylinders have the fitting flange holes almost in a parallel line to to one draw between the cap and the pipe end.

Something like this:

Goff, it is indeed a brake and is likely to be 0.7" bore while clutches are 0.75". Also your brake one is really an 1100/1300 one but as it's a Mini Jem that doesn't really matter.
You could unsolder it but you will burn off most of the zinc coating.

Ricardo ! Why do you always answer at the same time as me ?

Nick, we need to start doing shifts. I'm doing mornings

goff wrote:...Question- Can it be turned around 45 degrees ... I seem to remember they are soldered joints??????

Yes, its fairly easy to heat them up with a propane torch and rotate the reservoir.

goff wrote: This as been plated could the bottom base be un-soldered turned through 45 degrees ????

No the base plate isn't soldered on, it seems to be a press fit onto the cylinder with some sort of peining of the cylinder to the plate.

It may only be an Australian thing, but there is another configuration of tin tank clutch master cylinder which was used on later models (from 1977 here) that were fitted with dual circuit brakes. The brake masters were really big and chunky so they had to point the reservoir in a different direction again.

Tim

Thanks for the info lads
The numbers on the base are L16L4 ,opposite is a bit hard to read but goes like this 22221597 B3/4 , So i gather its a .75 bore ,Nick would that be right, It is soldered so i am still thinking of turning it through 45 degrees unless someone as a clutch master to swop for this one
Nick the other brake master cylinder is a new one from minisport cooper S/ 1275 GT
Thanks
Goff

Just out of interest, the flange is actually screwed onto the body, and then stacked to hold it (this was done early in the process, before the fluid ports were drilled / pierced).
-Although the surface of the flange in the picture is very rough, which suggests to me it's either a recent one, or has been shot-blasted (original flanges were stamped out of plate)

The other difference between brake and clutch cylinders is in the non-return valve.
-This is in the 3-legged nylon part on the end of the spring.
-If you are going to use a brake cylinder as a clutch one, remove the little spring-steel strip in this plastic part.

The idea of the non-return valve in the brake master cylinder, is that it is supposed to hold a small pressure in the system (from memory, about 4psi), to stop the caliper pistons from being pushed (or 'floating') back away from the pads.