I had never been satisfied with the performance of the rear drum brakes on my Cherokee. The 9" drums were too small for larger tires, they required constant adjusting and the parking brake never worked well. A rear disk brake swap was an obvious solution to all these problems. In addition, rear disk brakes are self cleaning which eliminated the problem of manually cleaning the drums after getting stuck in sand or mud. After reading that the disk brakes from a '94-'98 model Grand Cherokee was an easy and reletively cheap upgrade, I decided to give them a shot.
I got the calipers, caliper mounting brackets, one backing plate, all of the backing plate mounting bolts, both soft brake lines and most of the parking brake hardware used. I had to buy the rest of the parking brake hardware and the other backing plate from the dealer and I bought new rotors, pads and parking brake shoes from an auto parts store. All told, it cost about $250 for everything.
Here is a shot of the complete passenger side backing plate/caliper mounting bracket assembly with the old parking brake shoes.
The first steps are to disassemble the drum brakes and pull the axles so that the old drum backing plates can be removed. I'm assuming that you know how to pull your axles and disassemble your drum brakes so these steps are not shown. Disconnect the brake hard line and parking brake cable from the backing plate and remove the backing plate.
Here is a what it looks like after the backing plate is removed. This is a good time to check your axle bearings and replace the seals. Again, I'm assuming you can do these without my help and those steps are not shown. Note the brake hard line in the picture.
This shot shows how I reformed the brake line.
The hole that the axle passes through on the backing plate/caliper mounting bracket assembly is a little too small to fit on the 8.25 axle. I used my Dremel tool with a grinding stone to enlarge the hole until it fit snuggly on the axle.
Use the nuts that came from the ZJ to attach the backing plate assembly to the 8.25.
The next step was to attach the caliper to the mounting bracket and attach the brake soft line to the original hard line. When I removed the soft lines from the ZJ I marked which was the passenger and drivers side line. On the ZJ, these lines are routed to the caliper from the bottom. Because of the way the XJ hard line needed to be routed and to protect the new soft line from harm, I routed the soft lines to the calipers from the top. The brackets that are used to attach the soft lines to the axle on the ZJ were cut off. The soft line that was originally on the passenger side of the ZJ was used on the drivers side on the XJ and vice versa on the other side. This is done so that the proper side of the banjo fitting is attached to the caliper.
Here is a top view of the soft line attached to the caliper. Sorry for the out of focus shot, but I couldn't fit the camera and my fat head in the wheel well to get the picture.
Now the parking brake cable needs to be attached. To do this the return spring needs to be shortened to fit. The cable needs to be attached to the actuator arm and the attachment sleeve for the cable sheath needs to be trimmed. Disconnect the forward end of the parking brake cable from the adjusting bracket under the XJ to give enough slack in the cable to work with it. First eyeball the length of the return spring and trim it. I used some dikes to cut away what I didn't need. The hard part was getting the trimmed spring off of the cable. Next remove the attachement sleeve from the cable sheath. and trim the ears. This needs to be done so that the XJ cable will attach to the thicker ZJ bracket.
Below are pictures of the loosely attached cable. Also the attachment sleeve with one of the ears trimmed.
Now the parking brake shoes and the axles can be installed.
Next the new rotors and calipers with new pads. Make sure to clean all of the oil from the new rotors with brake parts cleaner before installing.
All that is left to do is bleed the brakes and adjust the parking brake.
