Brake Upgrade Question (with Transfer Case Drop BONUS Question)

[NateEnos]

First off: 2001 xj, 4.0L I6, AT, NP231

I got the teraflex rear disc brake upgrade that I have yet to install. In the meantime, I believe my brake proportioning valve has crapped out and will need to be replaced. I have heard that when converting the rear brakes to disc, a proportioning valve from a 4 wheel disc Grand Cherokee is a good move. Does anyone have a suggestion as to whether this is correct and if so what year GC and with or without ABS?

BONUS QUESTION!

I Just installed my Rough Country 4.5" lift. The kit comes with a transfer case drop. Is it necessary to install the drop?

[blondejoncherokee]

i use the spring from the zj with rear disc prop valve in my prop valve, the prop valves seem to loojk exactly the same

[yossarian19]

I'm with Jon, I think all ZJ valves look alike. The only difference is the guts, the internal spring & ball. Unscrew the plug on the front of a ZJ prop valve (with disc brakes, of course) and swap them into your prop valve.
Or buy an adjustable from Wilwood or somebody.
It isn't totally necessary, I've run my ZJ rear brakes without messing with my prop valve. Been a few years now, I've got no complaints.
The ZJ, by the way, is any Grand Cherokee from 93-98. 99-04 is a WJ.
On the transfer case drop... do you get vibrations while driving? If so, install the Tcase drop. If not, no worries.

[mjma]

I have crown vic/exploder discs on my rear D44 with the stock proportioning valve. I know some say that the prop valve needs to be messed with and I understand the reasoning. I was planning on doing just that after my swap by driving it with the stock one the brake balance is perfect...so I didn't touch it!! I would wait and see how the brakes feel before messing with the valve!!


If you don't have an SYE, you'll unfortunately need to drop the tcase until you can afford the SYE. You may also have to shim the rear axle in addition to the drop. I would get an SYE ASAP!!! transfer case drops are really just temporary bandaids.

[jasonsxj]

try this ? http://www.lunghd.com/Tech_Articles/..._Valve_Mod.htm i did to try to get more pressure to my back brakes on my d60. It worked ok ???

[Gaius]

I wouldn't mess with the prop valve if you still have stock front brakes. I did the ZJ spring/valve on both Jeeps (TJ and XJ), and on both the rears locked up well before the front. The XJ was real bad, and got very squirrelly in the rain.

Keep the stock prop valve.


edit: If you do upgrade the front brakes (Vanco or WJ), then do the spring swap. It's a great match to the increased front braking pressure.

[ericfx1984]

Originally Posted by NateEnos

BONUS QUESTION!

I Just installed my Rough Country 4.5" lift. The kit comes with a transfer case drop. Is it necessary to install the drop?

maybe, maybe not... just put everything together and leav the tcase drop out... if you get vibes put it in later...

[NateEnos]

Thanks for all the responses. I think my sticking point is i have to replace the vavle as my current on is not functioning. I'm just trying to decide whether to order an XJ one or a ZJ one.

[yossarian19]

How do you know it isn't functioning?
If you have rear disc, get a ZJ (with disc brake) prop valve.
If not, and you are sure you wont' have rear discs any time soon, get the XJ valve.

[stewie]

I did zj rear disks on my 95 xj. Did the prop valve at the same time- just swapped the guts. Braking is great! I could lock up 31s and now with 35s they won't lock but I can stop great even with a loaded down tent trailer behind the jeep.