i was wondering what people had done about the master cylinder on cj's when swapping in axles with bigger brakes. I am almost done with my 14 bolt 60 swap and im certain that the master cylinder will not push enough juice to fill the brakes. So im open to what ideas or advice on what you have done. thanks

Are you going disc brakes on all four corners?

I know on my CJ with the manual brakes I went with a 68 vette master for the discs, I am running GM 1/2 ton discs on all four corners.. The master will work with both manual and Power brakes..

If you decided togo this route you want the MC with the 1 1/8 bore.

how much did that cost and was it close to a direct bolt in? and did you replace the booster too?

mine is off a 79 trans am and it is a bolt up other than modifiying the push rod a bit ( shortening it) but works perfect!!

Remove all the original CJ brake stuff.... master, booster, any linkage.

I took the setup from a wrecked ZJ. Pulled the master and booster. (It's the usual dual diaphram booster). Look and see which port is front and rear - MARK IT!

It's a tight fit, but can be mounted in a CJ. You have to use that spacer between the firewall and dash. Make sure you get it. You might have to "clearance" the hood reinforcement for the resevoir. (we did 2 CJs .... one was ok, the other needed a bit of hammer power)

Center up the new unit as LOW as you can in the existing opening and drill 4 new holes to mount. ( Remember, keep as LOW as possible) Have to open up the center hole to clear the new booster. ( You'll see when ya get to this point.)

The rod fits right on a CJ brake pedal ( at least on my 85, I assume all CJs ?)

Bolt it up tight. don't push the pedal yet! might damage something in the booster/master.

I removed the stock prop valve. Used a T fitting to marry up the original front lines and ran them DIRECT to the master cylinder.

I plumbed the rears with an adjustable prop valve for street tuning. ( A dedicated trail rig might be able to skip this ?? )

Set up of prop valve: Get on some smooth blacktop.... lock em up from about 25 mph. Have a bud watch your tires. Back off the rear brakes until the front brakes lock up first, or at the same time. Very important! If the rear locks up first, this can cause a spin. (Trail rigs are exempt from this step )

NOTE: The ZJ master uses metric fittings... I found metric to standard adaptors at NAPA. But it was a PITA to get the right ones.

I am running 33's with 4 wheel discs. I can lock them at any speed. Almost too much boost.

You can also go to http://www.offagain.com and look at thier Navajo Brake Booster article. A friend of mine has done this and is running 60's front and rear with no problems with stopping.:D :eek: