Will a prop valve added to a drum/drum master work with discs?

Just like the ***le says. I have a dual reservoir master cylinder on my '57 F100 with stock drums all around. I will be putting a Jag cross member on it this summer with disc brakes. Will my master work if I put a proportioning valve on it or do I need to get one from a truck with disc/drums from the factory along with the prop valve?

 

Your dual master would not be a good choice, I believe disk brakes require more juice in the reservoir (my disk pistons are huge, compared to my drums) which is why disk/drum combo masters have a larger reservoir.

 

You would need to remove the residual valves from your stock master and as long as your master is above your calipers, you would be ok (as long as your volume to push the calipers is ok )

 

Just go to the auto parts store of your choice and get a dual res. master cyl. I like mid 60's Chevelle ones, but since you have something there already, Ford or GM, you don't say, get one that'll just bolt up to your booster.

Brian

 

You need to understand what a proportioning valve does. It functions as a choke point to limit how much pressure is allowed to the rear brakes. The master cylinder is just a reservoir to hold a supply of brake fluid and a plunger that pushes the fluid out to the brakes when you push on the brake pedal.

Disk brake calipers are larger than drum brake wheel cylinders and need more fluid when you push the brake pedal. That's why you need a master cylinder made for disk brakes or drum brakes for the system to work correctly.

 

I don't believe there are any residual valves in my system. I thought those were for master cylinders that were lower than the braking system. I have one large chamber and one small chamber in my master. I bought it as a bolt in power brake kit from CPP years ago. I'm not sure what it was made for originally, but it looks identical to this.

 

Here it is in the upper left

 

You may or may not need a prop. valve ,but on the PU you probable will. There is NO difference in function between a disk/drum and a drum/drum MC. The only difference would be the inclusion of a residual check valve. The reason the disk/drum MC has a larger reservoir is as the pads wear fluid stays in the caliper to take up for the caliper piston movement as the pads wear. The OPs master will work just fine with the Jag front end.

 

They call it a "corvette style" master not sure what year it's based off of