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1997 Jeep Comanche Brakes

tylergrant2011

NAXJA Forum User
Location
Luverne
Hi everyone I have a 1987 Jeep Comanche 2wd with the 4.0, and I was wondering if there was a way to upgrade the brakes on these trucks to give it firmer brakes. The brake booster on my truck has a leaking diaphragm every time I hit the brakes you can hear air hissing out and sometimes it seems to stick until I jab the brake pedal with my foot, but whenever I went to the parts house I noticed that these boosters we're only a single diaphragm setup. If anyone knows how to convert or upgrade these machines to a better braking system, I would greatly appreciate it. Thanks!
 
95/96 Brake booster and master. Bolts up with no mods. Keep your distribution block for the load sensing valve in the back.
 
MJ wasn't built after 92 so..yeah..an XJ. You can also do the WJ swap. Some say they don't have to move the washer bottle doing it that way but might need to modify the firewall lip. Do a search for dual diaphragm booster upgrade. Should give you all you need.
 
Correct. I have the 95/96 XJ booster swap on my 88 XJ and the firewall lip needed to be bent up a little for clearance and my washer bottle needed to slide forward a little bit.
 
I did a little reading and there was also an option for a 99-04 wj. It said to get the master cyl lines and booster and proportioning valve from 94-98. What is the best upgrade of the 2?
 
The upgrade would be the same - they are different but have the exact same specs.

The WJ upgrade was popular because for a time you could get junkyard WJ masters/boosters that were still fairly young - but now any XJ/WJ junkyard part is going to be so old its inadvisable to run it.

Get either option new from a parts hours or amazon. The XJ one will be less work to install most likely.
 
You also can supposedly run WK2 calipers & mounts with Ford Sport Trac rotors on your current MJ knuckles. You just have to drill out the caliper mount holes on the knuckle itself. This works for a 16" aluminum rim and some 15" steelies. I am in the process of converting and can post result when I am done.
 
You also can supposedly run WK2 calipers & mounts with Ford Sport Trac rotors on your current MJ knuckles. You just have to drill out the caliper mount holes on the knuckle itself. This works for a 16" aluminum rim and some 15" steelies. I am in the process of converting and can post result when I am done.

Is there an advantage over doing a WJ swap? I'd be interested to hear more as I'm planning the WJ swap for my MJ when I finish getting parts.
 
Is there an advantage over doing a WJ swap? I'd be interested to hear more as I'm planning the WJ swap for my MJ when I finish getting parts.

Only advantages that I know of are not needing new knuckles and steering. Although OTK for WJ knuckles is an advantage in itself if you haven't already upgraded your MJ steering.
 
Only advantages that I know of are not needing new knuckles and steering. Although OTK for WJ knuckles is an advantage in itself if you haven't already upgraded your MJ steering.

Cool thanks for the info. That is the biggest reason I want to run the WJ setup, better geometry. Only thing I did on the MJ was swap over my IRO tierod when I stripped down my XJ. I have a builder HP30 that is slowly getting parts. Although I still toy with the notion of just saying f it and getting tons.....
 
I'm running a 1992 (I think) Crown Vic rotors and calipers in the back on my 1989. The backing plate has the same bolt pattern and I had to make a spacer to hold the bearing in place. I also bought some off the shelf brake lines with the right ends to use the stock ford hoses.

Still haven't done the booster swap yet - I really need to. WJ would have had rotor in the rear and have an appropriate prop valve for that right? Probably swap out the load sensing valve for a fixed manually adjusted valve.
 
IIRC the WJ ABS HCU contains its proportioning valve/system. I'm not 100% sure of that though.
 
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