Installing discs on the front of my 50 Chevy PU.The calipers are from 70's 1/2 ton.Put a one inch bore dual master in the truck a few years ago.Will the brakes function ok with the 1/4 inch line ??? lines are like new and don't want to change them unless it's necessary.
Line size has no effect on the operation of the brakes. As much fluid as the M/C puts into one end, the same comes out the other end. The line is already full of fluid, doesn't "use" any in being a conduit for the fluid. That is, as long as there is no air in the system, but that would be a problem, no matter line size. Ray
You may have to step up to a inch and an eighth master cylinder. I put discs on a 57 Chevy several years ago and it wouldn't move enough fluid with a one inch M/C. i use a Corvette of mid 70s M/C. Remember, a small piston makes pressure and a big piston moves volume. It takes more fluid to move a disc brake piston than a wheel cylinder.
You are correct on the volume vs pressure difference with diameter...however, I did a disc brake conversion on a '47 Ford and utilized GM '71 tru '76 big car calipers which are as large a piston as is commonly found in these swaps. Rear brakes were rebuilt stock. I used a '67 thru '72 Ford Mustang M/C, which as I recall was 15/16", and most certainly no larger than 1", and no booster. I found that to be an ideal balance between pedal travel and pedal pressure. The big advantage to the setup was large F100/150 12" rotors and the large GM caliper brake pad size (friction area) made for lots of surface area and leverage when braking. Smaller sizes of both rotor and caliper dimensions may produce significantly different results. Probably adequate for the weight of the vehicle, but at the expense of high pedal pressure. A booster may be desireable. Ray
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