I have a single reservoir manual drum/drum M/C with 7/8 bore now. Want to convert to dual reservoir M/C and maybe manual disc/drum in the future. I found a dual reservoir M/C with a 7/8 bore and 1.10 stroke. Will this M/C support a manual disc/drum system?
06-29-2012 01:45 PM
It may there are many variables like the fulcrum point of the actuating rod on the pedal to the mc and the pressure ratio to your foot pressure and the size of your calipers.
I m curious as well because I'm in a similar situation. I do know that a drum/ drum mc will not work for disc/drum setup as it doesn't move enough fluid for calipers. I would like to know if a disc/drum mc would work for drum/drum setup.
07-23-2012 07:51 AM
I had a 75 corvette power master on my vega drag car. At frist we had it set up with manual drum-drum brakes and it worked ok. Then we went to mustang two front disks and it works perfect, No pulling,stops straight,easy pedal pressure. Rears are 11" chev 1/2 ton drums.
07-23-2012 10:11 PM
The only difference between a drum/drum, a disc.drum, and a disc/disc master cylinder is the residual valves. Drum brakes have them built in, and disc brakes don't. If you want to run drums with a disc brake master, install external residual valves.
An easy way to check the master for residual valves, try to insert a toothpick in the fitting on the master cylinder.If it goes right in the cylinder bore, there is no residual valve. If it hits something about 1.4" in, it has a residual valve.
If you have a firewall mounted master cylinder, you might get by with a disc master cylinder, with no residual valves, and drum brakes