master cylinder and 1tons

jeepeater2003

Member
Joined
Mar 21, 2005
Location
raleigh
hey all

was wondering for the people with one tons and 4 wheel disks. what are you doing for the brake master cylinders? Preferably for a jeep yj. I heard you can put an older style corvette master cylinder on. Any one done this swap?

thanks

tyler
 
My friend put a mid 90's S10 cab on a Blazer chassis with a D60 and 14 bolt with the typical rear disc conversion. He just plumbed the lines to the S10 master. I have driven it, and the brakes are great.
 
I've got a 'vette MC if you determine that's what you want.. 1" bore. It's almost a little too big for my application and full manual brakes, but I'm going power.
 
I also have a yj (whats left of it) , on 39.5 boogers with d60s discs f&r and i use a corvette master and a dual diaphragm booster with a vette prop valve from master power brakes in mooresville. Those people know brakes as that is all they do. They have been in the muscle-car industry for a while now and build some top notch stuff.

remember that if you use the vette master; the front and back ports on it are backwards. the front is for the front brakes and rear resivoir is for the back, most people dont reverse these and their rear brakes actually engage before their front. mp brakes can help you out with the rest of the tech stuff, its all in their free catalog!
 
Greg, is yours the 1" master, or the 1 1/8"? From what I remember when I bought mine, if you spec'd out a manual brake 'vette, you got 1" bore, and for a power brake 'vette, you got the 1 1/8"...
 
Good question rich, i really dont know, i dint bother to measure it before i installed it. I told them what i was doing and they sold me the shooting match to bolt right in. I will have to check the catalog and look up the specs.
 
Oh, it's stamped right on the MC... I wouldn't expect ANYone to go and measure the bore diameter of their MC.. :p
 
my rig is still down at CRS right now but when i stop down tuesday to visit her ill check the stamp.

do the different diameters of the bore affect the volume hence braking pressure???
 
F350 in mine... pushing dual piston Ford calipers in front and single piston 3/4t Chevies in rear. It's a 1-1/8" bore with vac booster.
 
Awsome,

ill run the vette i think with no porp. valve or just take the oring out of the stock one.
ill let you guys know how it works. well, when the jeep gets runnen

thanks
tyler
 
ok playing with my vette master last night. I thought i had good pedle... With heep running i have maybe 5% brakes..

Ive done so much reading and hear so many conflicting stories im not sure where to start... Ive hear about so many DOA reman masters. And then others that sound like my boster is bad?

Is there a good procedure to check for a booster ?

also on a manual master is the part that attaches to the pedle part of the master or a seperate item ? Mine appears to be part of the booster, and if i switched to manual brakes id need to find one of those ??? THnaks -mike
 
If the booster is bad, you'll either lose boost completely or the seals will stick, causing the brakes to stick on every time you hit the pedal. Those are the only two failure modes I've ever seen.

I've never had much trouble bleeding one out. Getting it 100% is one thing, getting it to 90% where it stops and you know everything is working is relatively easy.

First things first... I'd say you need to find out what the bore dia is for the m/c in question.... make sure that the booster stickout is roughly adjusted (static stickout should about match the static bore depth on the m/c.... err towards a little loose rather than tight) make sure the calipers are right-side up, no leaks, and all that stupid stuff, then double-check the bore size again.

IME, my 1-1/16" m/c didn't push nearly enough fluid for the dual-popper Fords and single 3/4t Chevies.... pedal was very low and very twitchy. Bumped up to 1-1/8" stuff, and it's perfect.
 
yager said:
also on a manual master is the part that attaches to the pedle part of the master or a seperate item ? Mine appears to be part of the booster, and if i switched to manual brakes id need to find one of those ??? THnaks -mike
Click to expand...

Mine is nothing more than a threaded rod that's attached to a clevis on the brake pedal.. it is not part of the master...
 
1-1/8 master (vette) i bench bled it for 15 min seemed fine, the NEW front calipers and the rears soaked up over a qt of fluid. etc.. ( i pulled the lines off again and rebled it again, seemed better, but after pumping 1000 times who knows.. maybe my leg was tired :D)

I agree completly about getting the system to 90% 'should' be easy...

I did mic out the old master and the new accounting for flang thickness variations, plunger bore depth etc.. and as it turned out i didnt need a push rod adjustment, was .003 dead on :flipoff2:

Shawn are you serious ? calipers right side up ? the fronts only go on 1 way.. :) the rears coulndt be in a more perfect spot...

Im thinking im go to try the e350 for grins... knowing my luck the vette master i have has been rebuilt 5 times in the last 30 years...

good news is based on what you said booster seems ok...
 
On mine, the calipers are mirror images of one another. You can put the DS on the PS and vice versa, but they'll be upside down. BTDT on one of those late-night shoulda-known-better benders.

They'd work fine that way, except for the bleeder port being in the wrong spot to let the air out of the caliper.

If you haven't tried bleeding it with the engine running, give that a shot, too.

Just throwing out all the possibilities.....
 
on the right track, rebleed bench bled vette master, rebled lines, same, zero pedel.

Bench bleed E350 master, swaped it on, and BAM brakes !!! I need to finish bleeding system but in its current condition i was at least able to hold the jeep in low range (4:1) so bleeding out the air should make it better...
 
This is interesting that so many folks have had to swap master cylinders to get the brakes to work correctly with ton axles. When my friend first started building his truck, I though for sure he would need a different one from everything I had read. It also just makes sense with the larger calipers. I don't know how large his master cyl is, but the brakes feel like a normal car when you drive the truck. The S10 cab came off a mid 90's 2 wheel drive model. Is the diameter stamped on the body of the master? Never paid that much attention. If so, I will look just out of curiosity.
 
so will i need the vette master cylinder from one with power brakes or manual brakes? and what bore is that incase they ask.

thanks

tyler
 
manual - 1"
power - 1 1/8"
 
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