Anyone know of a fairly straightforward conversion for my ‘60 LeSabre to run a dual chamber master cylinder? I’m OK with the big factory drums but a single chamber MC makes me nervous! This is a manual brake car.
You'll need a master cylinder with the same bore diameter as what you have, and the same mounting flange and primary piston design as what you have. The reservoir shape doesn't matter, but the two reservoirs should be the same size. If one reservoir is huge and one is small, the master was intended for front disc brake use, the large reservoir goes to to the discs. It would work just fine, but it's going to appear goofy. Once upon a time, the two main suppliers of master cylinders for GM vehicles were Delco and Bendix, and the primary pistons were different even though the mounting flange was the same. One used a shallow pushrod hole in the piston, the other used a longer pushrod and a deeper hole. I can never remember which was which. Point being, measure the depth of the pushrod opening for the piston in your current master cylinder, and match it to the depth of the new master. Maybe on manual-brake cars this doesn't matter. It sure does on power brake vehicles.
I understand matching the bore, which I have done. But what does the depth have to do with the performance other than different designs? Brake arm leverage would be the same as the mounting hole is unchanged, right? In any event, the original MC has a built in rod so I cannot assess the depth of the piston
I have a couple master cylinders from the drum brakes 1966 to 72.These will need to be rebuilt,but these are the ones we did use years ago.Bruno.
After internet searches, not finding a tremendous amount of info, took heed of one suggestion for using a drum/drum MC from a similar size car. So I got a ‘68 full size Chevy unit. Had to make a brake rod as the original is integral to the MC. Replacing all wheel cylinders as well.
Actually, that push rod DOES come out of the master cylinder (and you should save that old master cylinder -- as it IS a DELCO.) -- and you could have reused it. I have the wheel cylinders USA made -- brand new -- if you haven't gotten them yet... Yours, Craig.
The rod does come out? OK. I have wheel cyls from Oreillys, likely not the best. How much do you want for your set Craig? I went to a dual chamber cuz the idea of losing the whole brake system doesn't sit well with me. Wreck the car...hurt myself...hurt the wife and kids...etc.
