I have a few questions about brakes.
1. what is the bore on the stock master cylender on a 93 wrangler
2. anyone know what the bore on the MC on a 99 grand cherokee is?

I am puting the dual piston calipers from a 99 cherokee onto my 93 wranglers front axle (swaping knuckles and all) to get (hopefully) better brakes. My question is will I need a bigger MC because of the new calipers? I want to make sure the MC will push enough fluid for the dual piston calipers. I thought about swaping the MC off a 99 grand cherokee, but I am not sure if the lines hook up the same. What about swaping to one made for like a 1/2ton truck or somthing close? I thought about one like is on my 79 cherokee, it looks pretty close to the one on my wrangler now, I was thinking it is probably a little bigger and would push a little more fluid and work good with the dual piston calipers. Just incase it might matter, I have a ford 8.8 in the rear with discs on it and I have removed the little rubber washer in the prop valve to make the brakes work better and have had no problems with the rear locking up too soon. Anyone have any insight? Thanks.

I have Grand Cherokee dual piston calipers w/ Stainless Steel Brakes Pads and Disks.. I did not change the MC and I have had no issues with the front brakes.

However I have a '98 TJ and I have no idea how it's master cylinder compares to the '93. I guess my suggestion would be to try it and see.

- Shawn

Did you notice a diffrence in the brakeing ability? How mutch did it improve once you did the swap.

Well I can't really say I did it at the same time as a bunch of other upgrades (larger tires etc), plus I put on high dollar pads and rotor.

I can tell you that I have no problems stopping 37inch tires on steel beadlocks... and I know my rear drums are not doing their job very well so I know the fronts are currently working just fine.

Sorry that's the best answer I have.