zj disc swap proportioning valve shenanigens

ok so i did the rear disc swap on my 8.25, and now i need to get the spring out of a zj proportioning valve... which are really hard to come by near me... and there are no local "u pull its" around, and there is no way in hell i am paying 90 bucks from the stealership for one. so answer me this: can the xj spring be made to match the spring rate of the zj spring via trimming or something? or is the zj spring shorter, but a higher spring rate?

oh and no i cant just take out the o-ring, i am on 33's, so they will lock up really fast without it.

thx

G

Then just leave the stock prop vavle alone for now.

Many of us have been running the stock prop valve with rear discs for a long time now.

Yeah I am going to leave it alone for now, but I was thinking future to finish it off right. Just brainstorming really. It was something I hadn't seen in my saerches so I thought I would throw it out there

Long term, I'd probably pull the o-ring and put an adjustable prop valve in line.

for what its worth, I blew a connection to my rear discs and there was no safety afforded by the stock prop valve IE full pressure to the back, fluid everywhere, lost my brakes pretty quickly. I don't think it does much of anything in reality...
Been running my 8.25 with rear disc and it doesn't lock the rears in anything but a hard stomp through the snow... I can only imagine that it would be slower to stop but harder to lock up on 33s (I'm on 30s)
I wouldn't worry about it.

I run the stock one for now. I figure I would replace or remove the spring when I do the MC upgrade. I hate bleeding brakes.

Leave it and see how it goes. I've got crown vic discs on my D44 rear on 32s and have never had any issues with it, rain, snow, sleet, dry roads, wheeling, etc. I think the braking bias is right on....

ok well i guess i will leave it alone unless i happen to come upon a gnome offering up a zj spring to test. i have read too many threads on here claiming more significant improvements with the zj spring to discount it completely. thx for the reply


G

FWIW my 8.8 discs in my '90 all stock brake system otherwise and they work perfectly and stop WAY better than my '89 stocker....with 32" swampers