15" DIY Big Brake Kit for XJ/MJ/TJ/YJ/D30/D44
Thread Starter
CF Veteran
Joined: Dec 2011
Posts: 1,777
Likes: 22
From: PA KOTUFU!
Year: 1998
Engine: 4.0L 162,000
Dorman Speed Bleeders
12708- M7-10x32mm
12705- M8-1.25x28mm
12706- M10-1.0x33mm
12709- M10-1.0x35mm
12702- M10-1.5x33mm
12703- 1/4-28x1.0"
12704- 5/16-24x1.0"
12701- 3/8x24x 1 3/16"
12707- 7/16-20x 1 1/4"
12708- M7-10x32mm
12705- M8-1.25x28mm
12706- M10-1.0x33mm
12709- M10-1.0x35mm
12702- M10-1.5x33mm
12703- 1/4-28x1.0"
12704- 5/16-24x1.0"
12701- 3/8x24x 1 3/16"
12707- 7/16-20x 1 1/4"
Junior Member
Joined: Nov 2015
Posts: 51
Likes: 3
From: Central Arkansas
Year: Started as a 1987
Model: Cherokee
Engine: 4.0 Renix
I realize this is an old post but I recently did this upgrade and would like to share my experience.
I am using this brake kit with 15" aluminum Raceline beadlocks. I did have to do some grinding on the caliper so that the caliper to wheel gap would much more desirable.
I also did not have to grinding on the rotor. I am not sure if this is because I used the Ford brand rotors or something else but it is something worth noting.
On to the pics.
Here is the first test fit and you can see that it was tight. There was no interference with the wheel but it was VERY close.
After some grinding, I was able to get a gap between the wheel and caliper that I was happy with.
Here are the rest of the photos that compare the factory brakes vs the new 12” rotors and dual piston calipers.
Old factory setup
New Ford 12” rotors and Grand Cherokee/Durango calipers
Here are all of the components that I used. The rotors, calipers, pads, and new banjo bolts came out to around $380. On top of that you will need a 14mm drill bit, M14-1.5 caliper mounting bolts, and M14 washers.
Here are the caliper mounting bolts that I used. I got these from Oreilly's. They are replacement bolts for a 2014ish Grand Cherokee. These bolts come out to 40mm long instead of the 45mm bolts that the parts list calls for.
I also only used 1 washer at each bolt location between the caliper and the knuckle. Here are a couple of pics to show how far the shorter bolt threads into the caliper.
I have to say that there was a huge improvement with the new rotors. The stops are quicker and when I come to a stop, you can feel a big difference in holding power. I didn't measure stopping distance but I did do a little test on locking up the tires. I have a ball valve plumbed in to hold pressure on the rear brakes, like a parking brake. Another advantage of this is that you can also use it to shut off the rear brakes, like a line lock. To test the braking power, I went to a parking lot, shut off the rear brakes and slammed on the brakes at around 25-30 mph. The results were that the factory brakes would bring me to a stop but did not lock up the tires. The upgraded brakes did lock up the front tires. Now you don't want your tires to lock up because you will then lose control but it is nice to know that the power is there.
I am using this brake kit with 15" aluminum Raceline beadlocks. I did have to do some grinding on the caliper so that the caliper to wheel gap would much more desirable.
I also did not have to grinding on the rotor. I am not sure if this is because I used the Ford brand rotors or something else but it is something worth noting.
On to the pics.
Here is the first test fit and you can see that it was tight. There was no interference with the wheel but it was VERY close.
After some grinding, I was able to get a gap between the wheel and caliper that I was happy with.
Here are the rest of the photos that compare the factory brakes vs the new 12” rotors and dual piston calipers.
Old factory setup
New Ford 12” rotors and Grand Cherokee/Durango calipers
Here are all of the components that I used. The rotors, calipers, pads, and new banjo bolts came out to around $380. On top of that you will need a 14mm drill bit, M14-1.5 caliper mounting bolts, and M14 washers.
Here are the caliper mounting bolts that I used. I got these from Oreilly's. They are replacement bolts for a 2014ish Grand Cherokee. These bolts come out to 40mm long instead of the 45mm bolts that the parts list calls for.
I also only used 1 washer at each bolt location between the caliper and the knuckle. Here are a couple of pics to show how far the shorter bolt threads into the caliper.
I have to say that there was a huge improvement with the new rotors. The stops are quicker and when I come to a stop, you can feel a big difference in holding power. I didn't measure stopping distance but I did do a little test on locking up the tires. I have a ball valve plumbed in to hold pressure on the rear brakes, like a parking brake. Another advantage of this is that you can also use it to shut off the rear brakes, like a line lock. To test the braking power, I went to a parking lot, shut off the rear brakes and slammed on the brakes at around 25-30 mph. The results were that the factory brakes would bring me to a stop but did not lock up the tires. The upgraded brakes did lock up the front tires. Now you don't want your tires to lock up because you will then lose control but it is nice to know that the power is there.
Thread Starter
CF Veteran
Joined: Dec 2011
Posts: 1,777
Likes: 22
From: PA KOTUFU!
Year: 1998
Engine: 4.0L 162,000
Glad it all worked for you.
It looks like you have an older Jeep with the early knuckles.
This is basically a 'WJ front brake' upgrade without using the WJ knuckles and all the issues/work associated with them.
Looks great.
It looks like you have an older Jeep with the early knuckles.
This is basically a 'WJ front brake' upgrade without using the WJ knuckles and all the issues/work associated with them.
Looks great.
Senior Member
Joined: May 2010
Posts: 530
Likes: 0
From: Nevada City, California
Year: 2K
Model: Cherokee
Engine: I6 with Mustang fuel injectors; 60mm Throttle Body;
I would really like to do this as for the money and ease of instillation this is the best brake upgrade I have found. But will my locking hubs interfere with anything?
CF Veteran
Joined: Aug 2019
Posts: 1,467
Likes: 267
From: Littleton, CO
Year: '96
Model: Cherokee (XJ)
Engine: 4.0 HO
Just doing some looking around the forum and found this. Is there a specific reason to upgrade to 15" - 17" rotors and better calipers and all that? Are ya'll doing 143MPH down a trail or the highway and need to stop on a dime or something? Or is it just for "hey look what I did" reasons?
CF Veteran
Joined: Jan 2016
Posts: 1,242
Likes: 41
From: Newport News, VA
Year: 96 & 88 4 dr Cherokees
Just doing some looking around the forum and found this. Is there a specific reason to upgrade to 15" - 17" rotors and better calipers and all that? Are ya'll doing 143MPH down a trail or the highway and need to stop on a dime or something? Or is it just for "hey look what I did" reasons?
It's because the stock brakes will barely stop you adequately in a panic stop situation.
Add in larger tires, and that breaking distance starts to get longer very quickly.
I like to KNOW I can stop if needed.......
Member
Joined: Oct 2019
Posts: 247
Likes: 59
From: Fredericksburg, VA.
Year: 2001
Model: Cherokee (XJ)
Engine: 4.0
Just doing some looking around the forum and found this. Is there a specific reason to upgrade to 15" - 17" rotors and better calipers and all that? Are ya'll doing 143MPH down a trail or the highway and need to stop on a dime or something? Or is it just for "hey look what I did" reasons?