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WJ brake upgrade for a 2001 XJ... Simplified?

xjbubba said:
I believe the '01 XJ and WJ have the same bore size MC's. That would imply the caliper pistons are similar, if not equal in volume.
Not sure about the proportioning valve. If both apps are 4-wheel disc, then either will work.
The MC's are not the same bolt pattern. If you did need a larger bore size, the Dodge Durango MC will fit the XJ booster, and offers a 1.125 bore, versus your current 1.000 bore; the Durango MC won't fit the WJ booster, however.
Click to expand...


Not to hi-jack, but using a Durango master cylinder would that be an upgrade if using rear disc conversion on a XJ? Is it a bolt on to all XJ brake boosters?

As far as upgrading the front discs, I'm on hold till money is not going out as faster than it is coming in.
 
In my opinion, if you have a single diaphragm booster, then upgrade to a dual unit first. Selecting a booster to fit your long-term goals as they relate to caliper changes.
I found the WJ booster was a better fit to the XJ, requiring less mods, but available MC sizes were limited. I chose the '01 XJ booster because it would accept a number of different sized MCs; however, the booster sets at an angle to the fire-wall, and has a 1 inch longer rod running to the brake pedal. So mods are required either to the booster rod, or the brake pedal. I modified my brake pedal to accept the longer rod, but still have the pedal height the same as stock. The '01 XJ booster accepts an MC with a 3.15 wide x 8mm bolt pattern. My stock '88 MC pattern was different.
Whether or not the Durango MC represents an "upgrade", depends on volume changes you make in the brake system. My experience was, adding rear dics, with Cad Eldorado's metric calipers (smaller piston than "1/2-ton" calipers) required an upgrade to a 1.125 MC bore.
 
nosigma said:
I don't want to spread false info so when I get back to DC I will double check and post pics of the knuckles to verifyor disprove the claim of seperate castings.

John
Click to expand...

It took a while to get back to it all, but since I promised to reply.................

As the pictures above show the Akebono's and Teaves use the same knuckle castings but different caliper brackets. Checked my pile of parts and the WJ knuckles are all the same.

John
 
I picked up a 12" sport trac rotor and confirmed that there is no way in hell my OEM 15" eccos will work. Even with 1.5" spacers there doesn't seem to be enough clearance. This kind of put a damper on my brake upgrade now that I have to hunt for larger wheels. Luckily I need new tires soon so that isn't an issue to contend with.
 
Ah, crap, that's bad news. I picked up a set of 16x8 Moabs which I know will work, but I was hoping to keep my 15" Eccos for a set of thrasher/beater tires down the road... You're referring to these wheels, right?

cherokee.jpg
 
Markos said:
I picked up a 12" sport trac rotor and confirmed that there is no way in hell my OEM 15" eccos will work. Even with 1.5" spacers there doesn't seem to be enough clearance. This kind of put a damper on my brake upgrade now that I have to hunt for larger wheels. Luckily I need new tires soon so that isn't an issue to contend with.
Click to expand...

From what I am reading that you dont have to go up to the 16" wheels, if you have the right backspace on the wheel. and a lil shaving off the calipr, I have been doing a lot of reading on this same topic, and glad to see that youa re taking your time to simplify this mod. To me it seems everyone has there own way they did it, essentiallly all the same mod with differant parts....
 
anthrax323 said:
Ah, crap, that's bad news. I picked up a set of 16x8 Moabs which I know will work, but I was hoping to keep my 15" Eccos for a set of thrasher/beater tires down the road... You're referring to these wheels, right?
Click to expand...

That's correct, your wheels are eccos, same as mine. The problem is that the inner diameter of the wheels decrease as you get closer to the spokes. I plan on snapping some pictures this wekend, so I'll report back.

xjnuttier said:
From what I am reading that you dont have to go up to the 16" wheels, if you have the right backspace on the wheel. and a lil shaving off the calipr....
Click to expand...

This is why I tested with a 1.5" spacer. Most people use spidertrax spacers which are actually 1.25". A spacer does the same thing as changing the backspacing. I'm guessing that steel wheels would work, but the factory aluminum wheels have the changing inner diameter, as mentioned above. This is all speculation without placing the WJ calipers inside my mockup.
 
Markos said:
That's correct, your wheels are eccos, same as mine. The problem is that the inner diameter of the wheels decrease as you get closer to the spokes. I plan on snapping some pictures this wekend, so I'll report back.



This is why I tested with a 1.5" spacer. Most people use spidertrax spacers which are actually 1.25". A spacer does the same thing as changing the backspacing. I'm guessing that steel wheels would work, but the factory aluminum wheels have the changing inner diameter, as mentioned above. This is all speculation without placing the WJ calipers inside my mockup.
Click to expand...

I work for a Jeep dealer, and I know for a fact that the rotors are almost 14" in diameter without the caliper. That is why the 99-newer grands have stock 17" wheels. I know it will be tight just from that dimension. The one thing I think you are right about is that the aluminum wheels seem to be thicker than the steel wheels, and the rear edge kinda rolls up to the lip, VS. the alum,, which seems to be more of a 90 degree lip if you would. I hope you understand what I am writing, it makes sense in my mind as I am typing, LOL ... I think I also read a write up where someoone used the ford explorer calipers and rotors, I am not sure on that one, but I seem to think that was the case.
 
xjnuttier said:
I work for a Jeep dealer, and I know for a fact that the rotors are almost 14" in diameter without the caliper. That is why the 99-newer grands have stock 17" wheels.
Click to expand...

Let's keep things accurate here. WJ rotors have always been 12" in diameter, regardless of the model year or caliper type. Also, 99-newer grands came with either 16" or 17" wheels. 17's werent' offered until 2001, and it was a cosmetic thing that had nothing to do with the brakes.

WJ Rotor Reference:
http://www.napaonline.com


WJ Wheel Reference:
http://www.wjjeeps.com/wheels.htm
 
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Markos said:
Let's keep things accurate here. WJ rotors have always been 12" in diameter, regardless of the model year or caliper type. Also, 99-newer grands came with both 16" wheels and 17" wheels.

WJ Rotor Reference:
http://www.napaonline.com


WJ Wheel Reference:
http://www.wjjeeps.com/wheels.htm
Click to expand...

LOL you know you are so right on the wheels, I was thinking of the 05 and newer, but I am going to double check the rotor size on a Jeep here for service, and let you know, that was the claim from the Chrysler rep at training...
 
So, after reading thru more WJ steering upgrade swap articles than I can count, I've come to these conclusions:

I'm running 2001 TJ Unit Bearing Hubs right now and I have the JKS 1/4 hub spacers to weld on, so I'll need to run Sport Trac rotors to keep the rotors spaced properly in my Akebono calipers? Does this setup also eliminate the need for washers between the rotor and the hub?

I also need to pick up WJ Lower ball joints to be safe, although many have said that they run XJ uppers and lowers.

I'm already running a Vanco Big Brake kit, which I will be selling when I get the WJ stuff......I'm doing the swap for the steering benefits, as the Vanco kit stops my Jeep very well. I DD my rig on the freeway and I'm done with the poor steering response of an Inverted Y design.

TIA
 
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Be sure to post results of WJ vs Vanco brakes.
Also - couldn't you go crossover with the knuckles you have? Wouldn't change the drag link angle, though...
 
yossarian19 said:
Be sure to post results of WJ vs Vanco brakes.
Also - couldn't you go crossover with the knuckles you have? Wouldn't change the drag link angle, though...
Click to expand...

Define "crossover"? The Vanco kit runs a modified XJ knuckle to fit the larger calipers, I'm already running Currie steering modified for OTK. Not interested in the inverted T either....I want the WJ setup, which is how Jeep should have shipped all of their rigs.
 
XJEEPER said:
Define "crossover"? The Vanco kit runs a modified XJ knuckle to fit the larger calipers, I'm already running Currie steering modified for OTK. Not interested in the inverted T either....I want the WJ setup, which is how Jeep should have shipped all of their rigs.
Click to expand...
crossover - as I know the term, it means that the tie rod goes knuckle to knuckle and the drag link goes pitman arm to knuckle. Without the 2nd steering arm found on the WJ knuckles, this is accomplished by using heim joint steering. Drag link on top of the steering arm, tie rod under it & bolted together with one long bolt & a nut + washers.

Agreed - Jeep sold all the parts to make a really badass rig but never put them all in one place. 4.2 crank / rods, WJ knuckles steering & brakes, ZJ rear disc, the C 8.25 axle, 99+ intake, WJ steering pump, ZJ air cleaner... WTF - why not get honest and market them as Erector sets?
 
Right, but I prefer to run TRE's as opposed to heims, so no.......my existing knuckles will not accomplish my goal.

I'm trying to get some clarity here from those who have completed the swap, is it best to run Sport Track rotors with 2001 TJ hubs for a bolt-on with the proper rotor/caliper spacing , or stick with the WJ rotors and redrill to the 5 x4.5 bolt pattern to maintain proper rotor/caliper spacing?

Seems to be a mix of parts and the associated info varies in all the threads I've read. I yet to see a true writeup, that clearly addresses which components work best together.
 
From my understanding, if you use the Sport Trac rotors w/ the 01 hubs, you still have to space out the rotor from the hub to get it centered properly - the height of the sport trac rotor is 0.1" higher than the WJ rotor (2.6" vs 2.5")....so you need some washers that are ~0.05"

Me personally, I'm going to get redrilled WJ rotors, just for the simplicity. I'm sure I could find somewhere in town to re-drill rotors for me....
 
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