master cylinder up grade..

i got a 2000xj with a 4 wheel disc set up i got no abs.. what is the best/easyest master cyl upgrade.. i need more brake power now since i am going from 31 to 33 and often tow with it... ya i searched but right now my pc is toast so i snuck on the computer at work.....thanks

What upgrade depends on what calipers you've installed relative to stock. If your 4-wheel discs use the same caliper piston size as an ZJ/WJ, then you need the MC used for those applications. If they're from a 1/2-ton app, then you need a larger MC.

ok i installed a set of zj rear discs and have stock up front... do i just need the master cyl or do i need the booster too??? is it a bolt on fit?

Your 2000 XJ has a dual diaphragm booster, and either a 1.0 or 1 1/16 bore MC, according to Napa. The MC for the ZJ is advertized as 1.0, and the booster is also a dual diaphragm. So, other than getting an MC specifically intended for rear discs, I don't see any easy, practical upgrades, without going to larger front calipers & rotors. You could possibly awap in a '99-03 Dodge Durango MC, with the 1 1/8 bore. This would actually reduce pressure to the calipers, causing a higher and harder pedal.
You didn't say what combination valve you're using. The XJ's disc/drum valve would cause your rear discs not to function at full potential. So either gut your XJ valve, or install the ZJ valve.

ok i have gutted my propotining valve and installed a adjustable one...

Keep in mind, the XJ, ZJ master cylinders are the same.

To get good biasing, remove the washer on the metering valve (which you did) or get a ZJ proportioning valve.

The ZJ disc brakes are larger than the Ford disc brakes I was using on 32" tires and at times was wanting more brakes.

I got rid of my rear discs when I did my 8 3/4 swap and went to 11" x 2 1/2" drum brakes with 33" tires.

I'm much happier.

You dont change your M/C unless you pedal is near the floor ( need a bigger one then but you will have INCREASED pedal effort ) or too high ( need a smaller bore will will decrease pedal effort ).
To over come the increased leverage of the larger tyres you need larger discs like that fitted to a WJ or a brake kit from Vanco or like the ones I developed.

Gojeep said:

or like the ones I developed.

Click to expand...

Details! We need details!!

Gojeep, aren't the slots on the rotor pointing the wrong way? I thought that directional rotors had the slots "sweeping" low to high, with regard to rotation.

ren said:

Gojeep, aren't the slots on the rotor pointing the wrong way? I thought that directional rotors had the slots "sweeping" low to high, with regard to rotation.

Click to expand...

This is the same way that Brembo instruct to fit theirs and was told to fit them by the company who is producing the kits I came up with. He also races stock cars so you would think he knows which way. Have seen just as many the other way though so who knows just how much difference it makes?

The brakes shown are something I put together and is now being sold.
See my write up on it here. http://go.jeep-xj.info/HowtoFordBAdiscs1.htm

Also I heard there is one of these kits available from the last group buy that sent a batch to the US. Ask Chris about it. [email protected]