ZJ brakes not responsive

A while back I did the rear disc swap with ZJ parts, but replaced everything but the brackets really, so everything was new.

I pulled the spring and the plunger from the ZJ's master cylinder i got the parts from, but only installed the spring to my XJ.

Problem is I can't get my back wheels to lock up, even on ice. Its like all braking is going to the front. Is there something I missed? I have to replace my front rotors now because theyre warped to hell. Assumably from the front doing all the braking...

Most of the braking does go to the front. And you want the front wheels to lock before the rear.

I have read that you want to install all the internal parts from the ZJ combo valve (its not the master cylinder) in to the XJ's combo valve. Depending on the year the ZJ MC is no different from the XJ's. You did mean combo valve (aka prop valve), right?

Another thing to check is make sure you bleed the brakes sufficiently and the bleeder screws are on the top of the caliper.

Sorry when I said master i meant the proportioning valve...its been a while, I just remember its so close to the master it might as well be part of it.

That was part of my question, is would the plunger make a difference? visually they were the same, but they were anodized different colors...

The fronts are supposed to lock before the rear, but if you read closely, I cant get the rears to lock up, even on ice. The rotors and pads show signs of wear but in the gravel at work, they dont seem to do much. I've asked this before and didn't really get an answer. Everything you read on the net is different too...this guy only changed the spring. this guy didnt change anything, this guy didnt even need to bleed his brake etc etc.
I realized this back in the winter, but now that (I believe) its cost me a set of rotors I'd like to figure it out, but without just throwing money at it.

bump

someones gotta know

or link to a helpful forum?

The ZJ prop valve internals are different, you need to swap the plunger and end cap also.... let me find the pics i posted showing this..


EDIT: See this thread, you'll see pics showing the size difference in the plunger and end caps.

http://www.naxja.org/forum/showthread.php?t=978214&highlight=plunger

YOU DA MAN!!!!

Thanks you sir. I could search the forum and google all day long and not find that. ...in fact I have...

I dont think i kept the ZJ end cap though Search begins

Thanks again Overland!

With my rear disk setup all i did was remove the o ring and i can lock my rear brakes up. It increased the braking 10 fold after the disk swap, why not pull the o ring off like many write ups say to do? I would try that and just look for the zj internals that you need in the mean time, if the braking gets better then you know thats the problem, if not then theres something else you need to look at. I had to bleed my lines FOREVER to get the air out, it did feel good to bleed out all the old fluid tho since it was real nasty looking.

Make sure the rear calipers have the bleed port on top. With some systems it is possible to install the calipers on the wrong side which puts the bleed port on the bottom.