I have a question I'm hoping someone can answer regarding the master cylinder used for a '69 Chevelle with factory power discs/drums.

I'm upgrading to a Hydroboost system and was advised that a 1 to 1.125" bore master cylinder would be perfect; I happen to have the master cylinder I was running with the factory power disc/drums, but I need to know if the master cylinder has a checkvalve for the drums in the rear circuit. (the checkvalve in the rear circuit would be bad with my rear discs.) It doesn't appear to have one but I'd like confirmation.

Thanks!
Troy

You can plumb up a short piece of line with a gauge on the end and apply pressure to the cylinder. Once you supply a certain amount of pressure you should be able to let off and the gauge should go back to zero. If not and it is holding something like 5psi...then you have a check-valve in the MC. Those check-valves are suppose to be removable.