master cylinder

[rein]

Hi all.
I found the leak in my braking system. It is the master brake cylinder.
It is not clear to me if I can use a 13/16 master brake cylinder. I read the thread on master brake cylinders. My car was using 7" front drums with a 7/8" master brake cylinder. I changed the front drums to 8" but kept using the 7/8" master brake cylinder. Maybe this is a good oportunity to change to a 13/16" master. If I remember correctly the rear brake cylinders are 7/8"
Can I use this 13/16 master in conjunction with the 7/8 rear brake cylinders?
I assume I can because the brakes are checked with the warrent of fitness. But they don't check front/rear balance.

[Willie]

When the 8" front brakes were introduced the MC bore was reduced to
13/16", and at the same time the rear wheel cylinders were reduced too
to give correct brake balance. I ran an early MC on 8" fronts for many
years without problems. I only fitted the later size during an overhaul and I must say that I noticed no difference at all. The only minor point
I can think of is that the early larger bore may be more suitable if you are thinking of ever fitting disc brakes because they need more brake fluid displacement which would be helped by the 7/8" bore. I do not know if the early size is still available though?

[rein]

Thanks Willie.
Maybe it is a New Zealand situation, but both my 1966 1098 van and (948cc) 1961 saloon use 7/8 " rear brake cylinders. The saloon used the 7/8" m/c with 7" front drums and the van used 8" drums and 13/16" m/c.
Brake part suppliers in New Zealand tell me that the 13/16" m/c is not for sale in NZ (anymore?). If I want to buy one I need to order it in England.

Cheers,

Rein