In theory, If I were to put C3 Corvette discs on the front of my 67, what master cylinder would I need?
I already have a Disc/Disc 1 1/8" bore Corvette master. With a adjustable prop valve on the rear system, could It be used? Do drum systems need a residual (pressure retaining) valve?
Anybody with knowledge of this conversion (or brakes in general)? I know there is complete Booster/Master/prop valve kits listed out there, but I'm really just interested in the correct master for this application to start.
Cheers, Mark
Corvette master, 11" Delco Moraine booster ..
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65 Laurentian post, 67 Grande Parisienne 4 door HT.
i remember years back removing the residual valve from masters that were sold to work with drum/drum or disc/drum. you could possibly install a valve in the rear port...
As is the master won't work. You need the residual valve to keep the cups seated in the wheel cylinders, so adding one will cure that. With you adjustable proportioning valve you should be able to dial down the volume going to the rear as discs require more volume than drums. It may take a little playing around with the prop valve to find a nice balance. Find a nice big empty parking lot to play in.
Or you could look though a jobber brake parts book and find a disc/drum master with the same bore as your vette master so it will supply the right volume to those vette calipers, the drums are usually close enough not to matter.
-- Edited by DANO65 on Thursday 21st of April 2011 09:01:45 AM
Good info! Sothe wheel cylinders need some pressure to keep a seal, and to keep the springs from retracting the shoes. If not I assume you'll have a pedal travel issue as it moves to take up the shoes travel.
Since I already have the master, I think I'll just order a Wilwood inline 10lb residual valve.
As far as line placement goes, does it matter where the valve goes? Should it go before the proportioning valve or after?
I have this Valve already...
And will order this...
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65 Laurentian post, 67 Grande Parisienne 4 door HT.
One of these days I have to go pick up my disc brake spindles, they've only been waiting oh about 8yrs, still on the front of a 69 I believe in a friends yard. He always reminds me that they are there and how many times he could have sold them . Soon, then I can try out the vete rotors like you did.