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I am wondering about the universal kit from speedway
here is the description

Master Cylinder Booster Combo, Natural/Zinc, 1.125 in. Bore, 7.0 in. Diameter Booster, Kit
i have drums all around
have any of you guys used something like this?

it seems like if it moves enough fluid
and it will fit under the floor
it would be good
or is there something basic i am missing?

Hi Billy,

Should work fine with the following understanding;

New MC mounts with 2 bolts....original mounts with 3.......so an adapter plate is needed.
No remote venting of the new MC.....so fording is a no-no.
If you use the original plunger rod I don't know if there is enough room to open the top of new MC to add fluid....original has a small plug you unscrew

Otherwise a master cylinder is a master cylinder.

bob

thanks for helping me pretty much daily
i like the idea of a dual cylinder
and a booster would be nice too!
my floor boards are mangled by previous owners
so chopping a bigger access hole wont break my heart

Hi Billy,

I like the idea of dual circuits too. Hitting the brakes and having the pedal hit the floor is a sure fire way to crap your pants! I continue to search for a dual chamber MC with the 3 hole mounting pattern, but I'm getting the feeling that animal just doesn't exist. A brake booster would be a wonderful addition too. Let us know how it all turns out.

regards,
bob

A master cylinder is not a master cylinder. They have differing bore sizes for a reason. You are going to want to be as near as possible the same size bore with a replacement. You could go larger bore with the addition of the booster as the extra pedal effort will be masked by the boost. A smaller bore than stock and you may not get enough stroke to take up the slack of all the shoes AND the amount of extra mechanical advantage may make the brakes a bit 'touchy' to be mild about it.

just me wrote:A master cylinder is not a master cylinder. They have differing bore sizes for a reason. You are going to want to be as near as possible the same size bore with a replacement. You could go larger bore with the addition of the booster as the extra pedal effort will be masked by the boost. A smaller bore than stock and you may not get enough stroke to take up the slack of all the shoes AND the amount of extra mechanical advantage may make the brakes a bit 'touchy' to be mild about it.

thats why i want the same bore/capacity as the original
i thought i said that but i guess i didnt

w30bob wrote:Hi Billy,

I like the idea of dual circuits too. Hitting the brakes and having the pedal hit the floor is a sure fire way to crap your pants! I continue to search for a dual chamber MC with the 3 hole mounting pattern, but I'm getting the feeling that animal just doesn't exist. A brake booster would be a wonderful addition too. Let us know how it all turns out.

regards,
bob

i saw somewhere here how a guy made a plate to convert 3 to 2 holes
it sounds easy*



*famous last words.......

Hi Billy,

Whooooops! Just is correct..........my bad.

I assumed (never a good thing) that you were asking about concerns regarding changing from the stock MC to a dual chamber MC PROPERLY SIZED FOR THE APPLICATION. As Just said.....bigger isn't always better......and that applies to MC bores specifically.

regards,
bob

w30bob wrote:Hi Billy,

Should work fine with the following understanding;

New MC mounts with 2 bolts....original mounts with 3.......so an adapter plate is needed.
No remote venting of the new MC.....so fording is a no-no.
If you use the original plunger rod I don't know if there is enough room to open the top of new MC to add fluid....original has a small plug you unscrew

Otherwise a master cylinder is a master cylinder.

bob

i keep thinking about this
couldnt i just take a fairly thick hunk of metal plate
drill and tap it for all five holes
and just mount it?

Hi Billy,

Yes you can! That's just what someone on here did........and they posted lots of pics. I just have to remember the title and then you can search and see it. Memory is a wonderful thing......until you start to lose it. Growing old truly does suck!

regards,
bob

Found it!! Search "Dodge Trucks dual chamber master cylinder question" and you'll see the discussion we had a few months back about MCs. In this post I wrote;

" There doesn't appear to be any dual chamber MCs with the same 3 bolt mounting pattern as the stock M37 MC. But thanks to a fellow forum member who PM'd me there is a pretty simple solution. Go to the Builders Blog section and scroll down to the post entitled "Rebuild progress, Thread #2 IT LIVES!!!! PG 18" by Josh. Go to the second page and look at the 9th and 10th picture in the post.........they show a simple adapter plate that uses the stock 3 holes in the running board bracket to attach the plate, and the plate has 2 threaded holes to mount the dual chamber MC. Very clean and easy installation.

I think this is the easiest way to mount a modern dual chamber MC. "

That's the plate I was talking about.

regards,
bob

http://www.g741.org/PHPBB/viewtopic.php ... 2&start=16

That's the 1-5/16" bore dual MC for Disc Brakes. but the idea of the plate should work for any correct bore MC.