The Stovebolt Site Forums The Shop Area Driveline 1.5 Ton master cylinder upgrade

What would be a good upgrade in a dual master cylinder for a 1.5 ton Chevy truck and does it need a booster to work correctly, below is a link to a 1 1/4 bore master would that work or would I need something better.



dual master cylinder

Any ideas on a simple yet effective dual master upgrade to the original brakes, ether non power, power or hydro booster and try to keep under floor, well hydro is out of the question since the truck doesn't have power steering.

I posted this same question a couple of days ago,on "Big Bolts". You didn't state the year,but the answer is basically generic.I got 6 responses that said I needed a M.C. with a larger bore. Scott Ward came back,and "said" that he uses a M.C.,from a '71 Chevy 3/4-ton,on his '48 2-ton,and it works just fine. You double your reservoir capacity,with the dual set-up. Makes sense. Friend installed a unit made for the T.F. trucks,with a built-in booster. They bolt-up under the frame. Problem is,the reservoir would be located under the seat,making it difficult to re-fill easily. Works for him,since his is a bus,with a pedestal seat.Another option,would be to install a M.C.,without the booster,and have your hydro-vac re-built,or replaced. This would locate your reservoir closer to the stock position. Good luck.

Hy ratamugrosa, I installed a dual master cylinder/close coupled vacuum booster kit in a 1952 one ton a few years ago, the kit came with a mounting bracket (which I had to modify to make it fit correctly) it was a close fit to the parking brake on the transmission, but it did clear. I would use the largest bore master cylinder available with the kits just to make sure you have enough capacity. If the master cylinder was originally intended for a disc/disc setup, then you must install resisdual pressure valves in each system (10p.s.i.). If you wanted to you could install just a non boosted master cylinder and use the Hydravac to boost your brake pressure, unfortunately you would have to add another Hydravac to boost the second system, hope that helps.

Wow! never took that into consideration,3B! It makes perfect sense,although may get a bit expensive!

3B so if I use a booster / large bore master cylinder that will work for my needs as for my truck it's a 52 1.5 ton, I won't be doing any real heavy hauling with it might try and pull a trailer/tow dolly to haul a car/truck(future project's)would the 7" booster be sufficient or would I have to go with the larger size one.

Hy ratamugrosa, I think that the seven inch booster should work, you are restricted to size by the clearance at the mounting bracket supplied with the kit. There are some boosters available that are a double diaphragm type, which provide more boost, check with the supplier. Make sure you have all your brakes adjusted up properly before you start bleeding your new systems, don't forget to bench bleed your new dual master cylinder before you install it, hope that helps.