Master Cylinder replacement

[tsalas]

Hey guys,

I am having a surprisingly hard time finding a replacement master cylinder for my 1980 r65, has anyone had any success with certain websites in finding a replacement? I am hesitant to buy one of the "universal" replacements, any success with those?

[flybot]

I had the same issue when replacing mine. I have the single Brembo front caliper. I got mine from Capitol Cycle. I think it is larger bore than stock, but it works just fine and is OEM. Pricey.

[Bob_Roller]

Have you removed the piston and looked at the bore of the master cylinder ?

If the bore isn't pitted too badly, you may be able to get away with a replacement piston / seal assembly .

[Barry]

If yours is a single disc you should have the stock 13mm master cylinder. If you do have to replace it go for the later 12mm one that was used on the 81 - on models to improve the brakes.  Don't under any circumstances go bigger than 13mm unless it's a dual disc set up.

[nhmaf]

Your setup uses the round style master cylinder(?), which was less service-able than the later, rectangular style master cylinder.  These were phased out and partly why round ones are hard to come by and expensive when you do find one.

If you do have the round style, though it is more expensive, you might want to consider looking for a used rectangular setup in good condition- parts are more easily found for them, though you will have to change the brake lever parts, etc.

Is your m/c leaking at the base, or ?

[steve hawkins]

you can retrofit the 'square' master cylinder to the early twin pull throttle assembly that used to have the round reservoir type master cylinder -  with a bit of 'fettling'.

I have done so with mine.