[Boattail]

I have a Corvette-style master brake cylinder on my Speedster. I want to replace it with a non-painted aluminum billet unit to eliminate the problem with the dissolving of the paint from the resevior lid. I do not know the diameter of the cylinder bore and do not have the original part number of the unit. Can I determine the cylinder diameter by just pulling the unit away from the power booster and measuring the diameter of the cylinder with dial calipers, or do I have to pull the piston out?

 

[joe_padavano]

I have a Corvette-style master brake cylinder on my Speedster. I want to replace it with a non-painted aluminum billet unit to eliminate the problem with the dissolving of the paint from the resevior lid. I do not know the diameter of the cylinder bore and do not have the original part number of the unit. Can I determine the cylinder diameter by just pulling the unit away from the power booster and measuring the diameter of the cylinder with dial calipers, or do I have to pull the piston out?

That is exactly how you do it. Just measure the bore at the back of the M/C.

 

[Boattail]

That is exactly how you do it. Just measure the bore at the back of the M/C.

View attachment 620898

I was hoping that was the case. Great pic! Thanks for your help.