jwnova wrote:
:?: Does anyone know the bore for the master cylinder on a 69' Nova? Kevin,Phil,Glenn, ect. ect.? I'm upgrading but I don't want to take apart the brakes just to find out what it is. At least not until the new ones arrive.
replacing the stock drum/drum master cylinder with something that would work for a manual disc/drum or a disc/disc brake system. I learned that about a 1" bore Master Cylinder would be required. Since I'm trying to save weight from the car, I went with a manual S10 aluminum master cylinder from a 1985 Chevy S10, Wagner PN R105801 ($41 including core charge). This master cylinder has a 24mm (.954) bore and has a quick take up piston that should provide a higher pedal with this small bore cyl.
The downside to using the S10 master cylinder is the pushrod hole is very shallow which could allow the brake pushrod to fall out easily. This shallow pushrod hole I believe is common to all late model aluminum master cylinders that have the quick take up piston, both manual and vacuum models.
Here's why, the quick take up piston section is only about .56" diameter. If you drill the pushrod hole deeper, the wall thickness would be too thin.
Since drilling the hole deeper is out of the question, I made a "pushrod saver" bracket that attaches to the firewall to prevent the pushrod from falling out if the master cylinder sticks or the pushrod gets too loose.
Jeff I have pictures is you need them
phil