Rockfrog Posted January 28, 2014 Share Posted January 28, 2014 OK so I'm going to throw a ZJ rear D35 into my MJ ... cheap regear to 3.73 from 3.07 ... it's just a daily driver mainly stock vehicle so the D35 is fine for my needs. It has Disk brakes so I'm wondering how the load valve will affect that? can I just swap it in and drive? or will I need to tackle the prop valve at the same time/? More to the point can I drive to the fab shop, have them do the welding of new perches and bolt it up, then after the usual hookups and bleeds ... expect to be able to drive home? I've done the swap already on my XJ but I'm not sure on how the load sensing valve will affect things ... if it's not a problem then great, 1 step closer to 4wd (I have the matching front as well) Link to comment Share on other sites More sharing options...
MancheKid86 Posted January 28, 2014 Share Posted January 28, 2014 swap the proportioning valve at the same time, youll have full lock up in the rear too early otherwise iirc :thumbsup: Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 28, 2014 Share Posted January 28, 2014 Disagree. When I installed Explorer disk brakes on my D35 originally years ago, I kept the rear load sensing valve (LSV) and the original MJ distribution block on the master cylinder. I also added about a 2" lift at the same time and increased the length of the LSV rod to the axle by the same amount as the lift. I had great brakes and rear brake bias - the rears never locked up first even in a panic stop. A few years later I swapped in a 96 booster/master, and a D44 rear w. disks, and a little more lift. Rear brake bias remained the same, only more responsive brakes because of the new dual diaphragm booster/master swap. Everyone tells you to dump the LSV; I never will as long as it's working as it should when I'm hauling a load in the bed. If it ceases to function I'll replace it with one from a Toyota or something else. I consider a rear LSV necessary on any pickup that hauls heavy loads occasionally. The main reason folks dump the valve is because it's rotted out or doesn't function anymore (good reason to dump it); OR, it's not adjusted properly. That's probably the main reason it doesn't function correctly. If you don't have the FSM, below is the LSV adjustment procedure. Ignore the 85* gauge, it's not necessary, read between the lines. Align the valve shaft flat at the six o'clock position (90*) and it works as advertised with rear disk brakes (and the original drums). http://www.autozone.com/autozone/repairguides/Jeep-Wagoneer-Commando-Cherokee-1984-1998/BRAKE-OPERATING-SYSTEMS/Height-Sensing-Proportioning-Valve/_/P-0900c152800aa103 Link to comment Share on other sites More sharing options...
Rockfrog Posted January 28, 2014 Author Share Posted January 28, 2014 Perfect, I had a similar experience with my XJ ... still running the stock prop valve and the brakes lock up exactly as they were supposed to ... fronts first. No dragging rears and exceptional braking performance since the WJ knuckle swap. It was just the LSV I was questionable on. Thanks for the good news. Link to comment Share on other sites More sharing options...
mnkyboy Posted January 28, 2014 Share Posted January 28, 2014 I have a D44 with disc brakes, late model dual diaphragm setup,and deleted LSV with a late model XJ prop valve. On the road it seems to stop pretty well but on gravel it can get a bit sketchy, just touch the brake pedal and the truck wants to go into a drift. An adjustable prop valve is on my to do list. But as I said thats with a deleted LSV. Link to comment Share on other sites More sharing options...
benjy_26 Posted January 29, 2014 Share Posted January 29, 2014 I have a D44 with disc brakes, late model dual diaphragm setup,and deleted LSV with a late model XJ prop valve. On the road it seems to stop pretty well but on gravel it can get a bit sketchy, just touch the brake pedal and the truck wants to go into a drift. An adjustable prop valve is on my to do list. But as I said thats with a deleted LSV. Might be the lack of weight in the bed. I helped a buddy install a Ford 8.8 out of an explorer with rear disc brakes into his 96 xj. Everything was straightforward. Used the stock prop valve and it works very well. Link to comment Share on other sites More sharing options...
mnkyboy Posted January 29, 2014 Share Posted January 29, 2014 I'm sure that has alot to do with it,the rear of my MJ is alot lighter then an XJ. I just need an adjustable valve. Link to comment Share on other sites More sharing options...
Rockfrog Posted January 29, 2014 Author Share Posted January 29, 2014 Chatted with the guy I got the axles from and he's gonna pull the 95 ZJ booster (dual diaphragm) master prop valve and whatever else is attached. My LSV works great for now so I'll keep it and just update the booster and master eventually. My XJ runs WJ front brakes on the HP30, ZJ/TJ (mix) rear brakes on the 8.25 with stock booster, master and prop valve ... and brakes perfectly even in wet weather the rears don't lock up until after the fronts, rolling on 35s. It stops better than it did stock and tracks straight in all cases. My main point of concern was that LSV as it's a foreign concept to my addled brain. The entire braking system was redone previous to my purchase of the MJ so I was hoping it would work out similar to my XJ did. Thanks for the tips and experiences ... it's helping me slowly make the MJ better. Link to comment Share on other sites More sharing options...
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