View Full Version : 8.25 Rear Disc Brakes

August 14th, 2004, 10:57
I just got my ZJ brakes in the mail, and I'm getting ready to install them. I was windering if anyone here has done it and has anytips. They are for a D35, so I'm gona have to reem out the brackets a bit, but other than that they are pretty much bolt on.

small pederson
August 14th, 2004, 12:08
i think i remember reading one time that you have to make sure that the backing plates are the same width otherwise the bearings will fail. also, try searching, i guarantee this has been gone over more than a few times before

August 14th, 2004, 13:01
whip out the the check book for a membership there is a very indepth writeup in the members only tech area. you cant see it unless your a member, along with the other perks a membership is awsome! btw if you become a member your also become a member of united four wheel drive association, and that is something to be proud of they, are the ones behind for most of fighting to keep trails open.

August 14th, 2004, 13:06
eh, I already became a member of another forum and will not do it again. As much as I could use that write up, I'd rather not fork over any dough. Right now I barely have enough money to drive to work and credit is up over my ears. Thanks anyway though. I guess I'll just mess with the brakes and see what happens.

Hey SP, what do you mean make sure the backing plates are the same width or it'll affect the bearings. I don't understand how
a problem woould be caused.

August 14th, 2004, 13:19
sorry about the bad experance on the other forum i have nothing but good things to say about my membership here though. anyway this is somthing im going to do in the future, and while i don't think i would be alowed to post the entire writeup here i'm shure i could quote some of the modifing detals here. the big things that i rembered, is that you have to modify is the axle hole diamater of the zj backing plate. the brake lines have to be moved[hard line is just bent to piont in a different direction], and some changing of the parking brake attachment point. overall the hardest thing in the install that i could rember, was you have to pull the axles to do this. anyway have to go going to a jeep show.

small pederson
August 14th, 2004, 14:20
something like if the drum brake backing plate and your new disc brake backing plate arnt the same, the bearings wont sit right. i think that was for semi floating axles though, you shouldnt have to worry about c-clip axles

August 14th, 2004, 15:13
something like if the drum brake backing plate and your new disc brake backing plate arnt the same, the bearings wont sit right. i think that was for semi floating axles though, you shouldnt have to worry about c-clip axles

Yep, with the Dana 44s you need to either have a custom spacer made or use the TJ Rubicon retainer plate. All the links I can find on the ZJ disc brake conversion:


August 14th, 2004, 16:26
Thanks alot guys, I appriciate all the feedback. I'm gonna start the swap tomm.
One quick question, all the parts I got are from a junk yard. They guy said they are all operational, however I'm afraid rust may have taken its toll. The calipers look good though, do you huys think I should buy new ones and use these for a core or should I just try these. Also, the rotors are all rusty. They look brand new as far as wear, but the rust makes em look 20 years old. Can I just sand them down a bit and be good as new?

I think the rest should be pretty easy, I'll let you guys know how it goes. Thanks again. :wave

small pederson
August 14th, 2004, 21:03
that rust will come off with use

August 14th, 2004, 21:16
If the rotors are still true (not warped), have them turned. Also keep in mind rotors aren't that expensive, I got my rear ZJ rotors for $25 each at Napa, alot of places wanted that much just to turn them!

If the calipers look good, hook em up and bleed them to get any gunk out of the system, and slap some need pads in. Loaded calipers are expensive, and usually come with low-mid grade pads. I went with the Napa Cermaix pads front and rear after much searching and praise about them. Expensive, but hopefully they're worth it, supposed to be low-dust which is good because I hate brake dust.

Good luck with your swap, mine's scheduled for the first week of September. I just need a ZJ proportioning valve, YJ brake lines, the Currie brake hose kit, some new axle flange studs, and some Amsoil 90W and I'll have everything I need.

August 14th, 2004, 21:29
I haven't planned on switching the porp valve, think that'll cause a problem? Also, how does the e-brake hook up? Is it pretty much bolt on to the XJ stuff. I'll be starting tomm morning, so all of you NEED to be here when I start asking more questions, haha.

August 15th, 2004, 13:36
OK guys, the install is going great so far, but I need some help of course.

I have the brackets reamed and mounted, stuck the axle shaft back in, and trying to put on the rotors. The driver side does not go on, I guess the pad/shoes from the ebrake are out just a bit to far. How do I compress the ebrake to allow the rotor to fit. Also, I had to disassemble my Powertrax locker, if I have the shafts in, can I still adjust the ebrake, I wanna get that part finished so the RTV has time to dry.

August 15th, 2004, 15:48
First, make sure both rotors are the same. The e-brake uses a star wheel adjuster, so just turn the star wheel a few times to compress the e-brake shoes. As for the e-brake cables:


Although this write-up is for an 8.8, the e-brake mechanisms are 98% identical, so it will work. Good luck.

August 17th, 2004, 20:23
Thanks for that link to JU, it was a major help with the ebrake, but I still can't figure out what is wrong with my powertrax no-slip. I really need some help with this one.

As I said before, only the driver side wheel is getting power, but sometime the passenger will engage, its intermitten. I want to know if the slighly thicker backing plates for the discs would affect the operation of the locker. I guess the drum backing plate is a little bit thinner, so could this cause the one side to engage or not? If not, then its probobly an internal problem with the locker.

If know one here give me any insight, I will be taking it apart tommorow for instpection. I'm thinknig of streching the springs a bit to see if that helps, hopefully I will not any broken peices.