Master cylinder push rod diameter

[Robert P.]

I have a 71 with power brakes. I am installing a new master cylinder no. 5460346 GM restoration parts. The one on the car is a replacement. the hole for the push rod in the new master cylinder has a larger diameter than the replacement .Would any know if there is different diameter rods or what the diameter should be? Thanks for any help Bob

[Joe L.]

Re: Master cylinder push rod diameter

I have a 71 with power brakes. I am installing a new master cylinder no. 5460346 GM restoration parts. The one on the car is a replacement. the hole for the push rod in the new master cylinder has a larger diameter than the replacement .Would any know if there is different diameter rods or what the diameter should be? Thanks for any help Bob

Bob----

The orifice in the master cylinder piston is somewhat tapered. I don't think that you need to be too concerned about the OD of the surface end of the orifice. What IS important is the depth of the orifice. It should be the same as the master cylinder you're removing and the rod, as installed, should fully seat into the bottom.

[Robert P.]

Re: Master cylinder push rod diameter

Thanks Joe, All other measurements are the same. I am going to start the install. Thanks again Bob