97+ XJ, rear disks and prop valve

[Kejtar]

I need a show of hands please. Who changed out their prop valve on a 97+ XJ when they upgraded to disks? Who originally had the stock propvalve and then changed it to a bigger one when the disks weren't holding right? And who kept the stock one and was happy with it?

Thanks

[kubtastic]

2000 - no changes under the hood (except for pulling some ABS fuses)
I'm happy with it, but I also travel light.

[johnsoninc86]

1998, zj discs, and I removed the prop valve oring. It definately sends a lot more fluid to the rear. The balance between the front and rear isnt exactly what i would want, but it still stops a hell of a lot quicker than before. The rears lock up just a little bit before the fronts do, but I expect it and can handle it in emergency situations. Im thinking about swapping in a zj prop valve already set up for discs.

[Ramsey]

dude just do it, i'm tired of seeing your posts because they remind me that i still havent done mine yet and that scott needs to hurry the hell up!

[falcon556]

I need a show of hands please. Who changed out their prop valve on a 97+ XJ when they upgraded to disks? Who originally had the stock propvalve and then changed it to a bigger one when the disks weren't holding right? And who kept the stock one and was happy with it?

Thanks

What about a 96XJ? It's as good or better than a 97+ :-)
I replaced the prop valve, nothing locks up because of the ABS, they feel good.
I am very happy with the conversion.

96XJ, 4.0, AW4, NP242.

[Kejtar]

What about a 96XJ? It's as good or better than a 97+ :-)
I replaced the prop valve, nothing locks up because of the ABS, they feel good.
I am very happy with the conversion.

96XJ, 4.0, AW4, NP242.
I asked for 97+ cause I didn't remember when the booster and the brake setup change :D

[falcon556]

I asked for 97+ cause I didn't remember when the booster and the brake setup change :D

OK, I felt left out :D
Best I can remember, it was 96.

[BRIANHO13]

98 left it alone, does fine.

[natep1]

2K, oem prop valve.
Better than the drums but are still kind of sucky.
I have an adjustable prop valve to install but, I just haven't had the time/motivation to fab the brake lines.

[falcon556]

2K, oem prop valve.
Better than the drums but are still kind of sucky.
I have an adjustable prop valve to install but, I just haven't had the time/motivation to fab the brake lines.

I used the ZJ valve. had to remove the original from the bracket and stake the new in, spliced the ZJ connector.

[Kejtar]

2K, oem prop valve.
Better than the drums but are still kind of sucky.
Can you define sucky? Soft? spongy? not enough braking power?

[Kejtar]

I used the ZJ valve. had to remove the original from the bracket and stake the new in, spliced the ZJ connector.
the connector doesn't fit? :(

[Bent]

Didn't we just have this thread?


Same answer; '01 w/Explorer brakes, no other changes to the system, real or imagined.

[mmmkay325]

On my 96xj I had swapped 97zj disc on the rear of my 44 and just wasnt happy w/ the proformance...so I just recently swapped in a ZJ proportioning valve....ewww weee that definately made the difference. I haven't messed w/ removing the oring that everyone talks about, but this worked great for me. Search mmmkay325 on these boards, I started several postes talking about my braking issues...I hope that helps ya.

[natep1]

Can you define sucky? Soft? spongy? not enough braking power?
Soft and spongy!
I think it is all due to now having an incorrect prop valve. They stop great but until that point in the pedal travel they are lousy.

[johnsoninc86]

Did you bleed them properly? Sorry if that is a dumb question, but I had like four guys helpin me put brake lines on, and three of them looked really confused and asked me what I was doing when I was bleeding the lines. From what I have learned, if they are soft and spongy, you usually have air in the system somewhere.
On my 96xj I had swapped 97zj disc on the rear of my 44 and just wasnt happy w/ the proformance...so I just recently swapped in a ZJ proportioning valve....ewww weee that definately made the difference. I haven't messed w/ removing the oring that everyone talks about, but this worked great for me. Search mmmkay325 on these boards, I started several postes talking about my braking issues...I hope that helps ya.
How hard was it to swap in the zj prop vavle? Was it a direct fit? Or did you have to reflare lines and put new fittings or something else on?

[mmmkay325]

on my 96 it was a direct swap. All the lines and fittings lined right up. The only thing you will have to reuse your old mounting bracket, the zj one is bent differently.

[natep1]

Did you bleed them properly?
Yup, several times. I did them manually & with a Mitivac.

[Bent]

Soft and spongy!
I think it is all due to now having an incorrect prop valve. They stop great but until that point in the pedal travel they are lousy.

Cheap, worn or over length rubber brake lines can also contribute to that feeling.

[falcon556]

the connector doesn't fit? :(

No, not even close, I had to splice the ZJ connector.
For more details: http://members.cox.net/nraok2/

[ghettocruiser]

Hey all. Did this to my 94. Kept the stock valve. MUCH better stopping. However I get the feeling like something is draggin back there. Along with wanting even better stopping power that is... Im going to swap the valve soon.

ANyone use any other valve besides a ZJ??? Im still toying with the idea of running no valve at all for the fronts, and putting a willwood adjustable in for the rears. I like the simplicity... but this is my DD so I DO need it to work good.

Justin

[JEEPZZ]

I put Explorer rear discs on my 87 D44. I removed the prop o ring & it worked better than stock but not what I'd consider ideal.
I've since moved that axle into my 97 and again removed the o ring. My 97 stops MUCH better than the same set up in my 87.
Even though I'm on 35's' it also stops much quicker than my wifes bone stock 97. All XJ's listed are non ABS.

[basalt51]

'97. EB 9" w/ discs, no changes, stops great. Little soft at first, great feel after first bump, need to bleed some more I'm sure, I'm just lazy.

[LilRedRover]

don't know if it's too late for this answer but when I did my rear disc on a 99 XJ I ordered a new valve from a company called Wilwood. Aside from the fact that no matter what I do when i brake it pulls to the right... no complaints