Proportioning Valve?

[Pookapotamus]

I have done a search but did not really come up with the answer that I am looking for and am now a little more confused.

I converted to rear disc brakes with the Teraflex kit a while ago, noticed an improvement in stopping but have heard that swapping the proportioning valve out will help even more so. With my current build I gutted all the brake lines and it is now time to add all those brake lines back in. so I have picked up a Zj rear disk brake proportioning valve and promptly threw out the old Xj rear drum valve.

My question is this, the Zj Valve has one more line run from it than the Xj valve did and reading on the forum it looks like I could have just swapped the spring and valve rod. So what do I do? can I plug that extra port? do I have to pick up an Xj valve and swap the guts? What are my options here?

Pook

[07Negative]

I haven't done the work myself yet. But I've been combing over this to get acquainted.

http://www.go.jeep-xj.info/HowtoZJvalve.htm

[4.3LXJ]

Pook, Abovetimberline on this forum has done this with stock ZJ stuff. PM him and see what he says

[Ringo]

seen your post. I converted my 1999 xj by installing a 99 mountaineer rear and disc brake setup. Easy fix from drums to disc.

do not replace your xj proportional brake valve. Mounting is different from zj to xj.

1.) ordered a zj proportional valve for disc brakes from dealer.
2.) measure the break line outlet holes for the rear breaks in the zj proportional valve and drill the same size holes in the xj proportional valve outlet holes for the rear breaks. The disc break caliber requires more fluid pressure than the drum breaks require.
3.) take internal guts from zj and install into the xj proportional valve

4.) Stopping will be of factory spec. Do not over drill hole size or a brake lockup condition will occur

[Pookapotamus]

thanks Ringo

So the holes that I have to re-drill are on the actual valve? if I am swapping the guts over does that not replace the valve? Or am I re-drilling the valve body?

all ready have the zj valve mounted in my jeep, as I completely gutted the jeep and have to re run all the lines, mounting was not a problem. since the zj valve is in there and I don't have another xj valve kicking around can i not just stay with the zj valve and run the lines? If so my question is what do I do with the extra port on the valve?

Confused Pook :stars:

[Ringo]

since you have the zj already installed, go with that with the internals that came with it.

Here is the question. zj, xj or tj doesn't matter.

The zj proportional valve you have, is it for disc brakes or drum brakes. makes a difference. The drilled port holes in the pv are sized for pressure to the brake system.

as far as the back port. If you DO NOT have abs, the back port is utilized. I will have to recheck the plumbing. It was the only line that I had to make up. The others go to their stock localities.

If you have ABS, the back port is block off. I deleted the ABS unit in my 99 xj. still stops on a quarter. Dimes are for performance cars. (a funny)

I will reply later tonight on the plumbing of the rear proportioning valve.

[xj4life2]

If it were me ... I'd buy a adjustable valve and be done with it.

[Ringo]

ok,

correction on the plug or no plug of the proportioning valve.
Plug the back of the proportioning valve if you have non-abs unit.

i added picks of what i done to my 99 xj by removing the abs system and adding disc brakes to the rear. The pics are of the proportioning valve of stock XJ type with zj internals.

as far as the brake lines goes it is like this;
the top two lines go to the resevoir
the front bottom line goes to the rear brakes
the back bottom line goes to the front brakes inwhich i added a junction block and had to create one break line to the front driver side

hope this helps.

[Pookapotamus]

Thanks Ringo!

I dug through all of my pics of all my xj's to see if I could see the routing. came up with basically the same as you with the exception that the rear of the proportioning valve goes to the drivers front and the bottom rear goes to the pass front, thus eliminating the need for the junction block that you used. I will confirm with a buddy's xj before I go ahead and run these lines.

Thanks for everyone's help!:thumbsup:

[Jeepster19]

Let me know what the final outcome is because I'm fixing to do the same thing on my 98.Pictures would be best so there's no doubt.Thanks!:D

[Pookapotamus]

Will do, well when i finally get around to doing this. :rolleye0012:

[Dredwolf]

Will do, well when i finally get around to doing this. :rolleye0012:

Also following this, I am doing an 8.25 swap and thinking about first tossing the ABS master cylinder, booster and valve to be done with it.

Discs are in the future at this point, but I want to get rid of the ABS ASAP just to get it out of the way.