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Hello, my 1989 jeep Comanche long bed that I have, has been dealing with some drum issues going through inspection. I bought the jeep and and it already had what looked to be new shoes around 4 to 5mm of meat on both sides. The drums although I would say have seen better days. My question is, could I sand down the shoes really well and slap a new drum on?(its a Dana 35 rear too I should add). I have heard mixed things on throwing a new drum on somewhat used shoes. Should I give it a shot?

Alright folks, where do I buy a new/refurbished/used stock proportioning valve (or distribution block according to some, but I'm unsure)? I've been trying to bleed my brakes for 2 days now but my front right will not bleed, albeit by gravity, vacuum, reverse bleeding, the works. I've read in a number of places that the little "pin" in the proportioning valve has done it's thing where, when bleeding, it decides to cut off flow. Trouble is, I can't get the "pin" to go back to resting position. I tried manually pushing the pin after removing the brake light sensor gizmo on the prop valve, but that didn't work. Tried bleeding in different orders, that didn't work. Tried slamming the brakes with the engine running and not running. ETC. I tried everything but couldn't get that line to open up. Where can i find a replacement? If not replacement, what easy mod can I do to keep as much stock as possible? Base model 88 short bed - 4.0L 4wd automatic 75k miles -General notes: years of squishy brakes premature locking of rear tires when stopping general pull to one direction when braking ^^^ new repairs include all plastic lines, calipers, pads and master cylinder are new no mods 29inch tires no lift no pinches or clogs in rubber or solid line, from caliper to prop valve desire to keep as much stock as possible but willing to lightly mod to have a running jeep that stops for once Questions, recommendations, links to other posts, all are welcome.

Ok guys, what is the best route in dealing with that height proportioning valve on my rear brakes. It nasty it’s rusty and i don’t know that it even works anymore like it should. I have a suspicion that it might be clogged. Does that ever happen? I say that because when I bleed the rear brakes the brake fluid doesn’t gush out but rather spurts out. However when messing with the arm on the valve I got the fluid to bleed out better but still not like it should. Either way I’m doing some brake work back there and it’s time to address this valve. Can it be rebuilt? I know buying a new or used one is never going to happen. So if it can’t be Rebuilt what are my options. Is there a practical way to bypass it? Any input is appreciated.

Hey guys, If it's needed: 1989 with old Renix 4.0 - stock dana 35 I am trying to do a WJ master cylinder / brake booster swap since the old one was rusted out with a leaky booster. In the process of installing it I accidentally crushed the proportioning valve when putting the lines in so I have to replace it. I have put two new proportioning valves in but it leaks from the same two each time I thought I tightened it down without pushing the line in first so I put another in and clearly that wasn't the issue. I bought an XJ proportioning valve and will not be using the front brake line (deleting the special proportioning valve toward rear). I don’t want to throw another in there and just “tighten it down” because it’s about $80.00 (part + shipping + tax) with about a week and a half to get to my house and it would do the same thing. Regarding the lines: I took the fittings off the old MJ brake lines and put them on the WJ brake lines that I pulled from the junk yard with the master cylinder and booster. I couldn't get a good flare using a tool from an auto store so I took it to a brake shop and had them flare it for me. The fitting on top toward the rear is 1/2" and the other one is 7/16", all other brake lines (bottom and on the side toward the rear) are the stock brake lines and flares. Anyway, the ones that are leaking: Top toward the rear Bottom toward the front (see picture – also has part number for new proportioning valve) They leave indents like the line isn’t sitting centered. I push the line in first and make sure it’s sitting where it should be THEN tighten the fitting but it still does it. I can’t figure it out, the flares look okay (also pictured). But again, I’m new to this so I’m kinda stuck on where to go from here. Any help would be appreciated! If it’s the flares then can someone recommend a tool that is different than the standard $15.00 one from the Auto store? That thing is too inaccurate for how accurate these flares need to be and I can’t keep bringing these lines to a brake shop because the flaring they do isn’t working either (plus I would rather not remove that bottom line to flare it and cause another issue with the fitting further on down the line. Maybe a hydraulic tool that isn’t the $300.00 one from amazon?

While my Comanche was parked over the course of 2 days I almost completely lost my brakes. The rears are worse than the fronts. The fronts will lock up, I'm not sure the rears are working at all. Parking brake also doesn’t work anymore. Any ideas? It must be both rear brakes as it doesn’t pull while braking. The reservoir was low, but not empty and hasn’t lost any fluid since I topped it off. Can’t see any leaks, brake proportional valve is still installed, but is tied up, and is also not leaking. (When I checked initially, it was down, but brake pressure never increased when putting it back up. None of the lines are leaking up to the master, nor is the master. The brake light on the dashboard is illuminated, but will go out if I pump the brakes. I didn’t want to get pads yet, but if I have to I have to. Don’t really want to drive it like this up to the Cars and Coffee meet. Pedal basically goes to the floor and I have maybe 1/2 of decent brakes. Brakes worked like a dream before this.

Hey guys I was instructed by @Pete M to write a new write on swapping disc brakes. This is my first write up and being one of the younger guys on the forum feel free to critic the write up. **You can easily do this swap in a few hours, given you have the tools and are handy.** First things first find your local salvage/junkyard and find a jeep liberty with rear disc brakes. I personally used an 04 liberty. You are going to pull all the good stuff, backing plates, rotors if they are good, calipers (to use as cores for new ones), brakes lines, e-brake components minus the e actual ebrake cables because we will be re-using the stock comanche ones If you are lucky like me the wheels will be off the liberty, so all you will have to do is take off the caliper, pop the diff cover, take the 8mm cross pin bolt out, push the axle shafts in, take out the c-clips, and pull the axle shaft out to give you access to you the backing plate. which should look like this.... undo the 4 bolts and everything should come out in one piece. Now back to where you have your beloved comanche, set the rear up on jackstands and repeat the same process to pull the axle shafts out and expose the dreaded drum brake backing plate its 4 bolts just like the kj backing plate, be sure to be use generous amounts of pb blaster, elbow grease and a hammer to knock off the backing plate. once its all off, you can take your kj backing plate and mount it on your axle Once the backing plate is one, you have to use your hammer once again and hammer out the old wheel studs as they are not long enough to mount your wheels and tires safely with the now wider mounting surface of the disc Part numbers: the studs I used are the front wheel studs from a 1997 jeep cherokee dana30 they fit perfectly once you have the studs in, you can go ahead and reinstall your shafts Now the only specialty tool you need is a double flaring tool found at most auto part stores. Yours may allow you to rent, but I had to purchase mine. It is a tool like this. ** I watched several youtube videos on how to flare brake lines before attempting doing this, and recommend you doing it as well.** You have to swap the fittings on the kj lines because they won't thread into the distribution block on the 8.25. So you cut the end off the kj line and pull the old fitting off. Since I used the original fittings, it didnt slide the easiest over the kj line so I used a blow torch to heat them up, to expand them and slide it over the kj line. After the "new" xj fitting is on, match the brake line to one of the holes in the flaring tool and flare to your hearts desire. Once the flaring is done, you can carefully bend your brake lines and run them how you want them. I still have to fix mine as I want the line to go under the leaf springs but I wanted to get it hooked up and tested. After all this is hooked up, you can install your new pads, rotors and calipers. I went with the drilled and slotted flavor mostly for aesthetics and performance too Bleed your brakes and off you go. I really like how it feels with how little driving I have done around my neighborhood. I can't really compare the disc brakes to drum brakes because I never drove my jeep with drum brakes but from what I have read it is an upgrade over stock. If you have any questions, please let me know so I can answer them to the best of my ability. Also let me know if you need more pictures

Had a caliper hang up on me yesterday so figured it was time to replace both as well as pads/rotors. Was going to use the duralast rebuilt calipers and gold pads/rotors, but does anyone have further recommendations? Also, while I'm doing the job, anything else i should look at maintenance wise/replace?

So I've done a good bit of research and can't seem to find what swapping in a ZJ proportioning valve will look like. My plan is to swap to a '96 booster and MC from a ZJ, swap in a ford 8.8 (rear disc), and use the proportioning valve from the ZJ to delete the factory load sensing valve. Any info on the p-valve fitting sizes and line work that would need to be done would be great! Thanks in advance!

I know there are many threads that explain this procedure but another won't hurt from someone elses experience. So, this weekend I am starting the dual diaphragm conversion on my 1989 MJ. To start off, here are the tools and equipment I have so far: 1996 XJ Brake Booster and Master Cylinder (bought off of JC Whitney) $170 (2) 3/16 diameter bubble flared with 10mm fitting brake lines STANDARD flare tool (rented from auto parts store) (1) 12mm thread 3/16 diameter line, fitting (1) Vacuum Tool (4) 10mm stop or lock nuts (1) Line cutter The four 10mm nuts are for the brake booster. The other two bolts on the other side can use the nuts off of the stock MJ booster. I chose to buy the bubble flare lines because the 1996 MC takes bubble flare ends and not double flared. The MJ distribution valve body DOES take double flare though. So, I am going to have to flare one end of each line using the standard flare tool. Also, one of the ports on the 1996 MC takes a 12mm fitting which I will have to slide on the line before flaring again. 1996 XJ brake booster 1996 XJ master cylinder currently being bench bled using vacuum tool Vacuum tool This tool made the bleeding process a little easier. There are many ways to do it. Putting each of the hoses from both fittings into the bottle and pushing the rod in, will have the same effect. I did both methods just to be sure. That is where I am at right now. Tomorrow I will start the upgrade!! :wrench: Also there will be lots of more pictures! :clapping: :thumbsup:

Hey guys/gals. So i started to build up my 87 Jeep MJ drum brakes and when i was tearing them down a few weeks ago, I noticed there were no parts inside except the driver side wheel cylinder. So I went to my local auto part store and ordered all that i could but am unsure of what all I need. Does anyone have a complete list or could they help me find a few of the levers/struts that go inside of it? I know I'm missing the park brake lever, the strut and spring and the shoe guide plate. Id like to mention it has a dana 35 with the 10inch x 2 1/4in brakes. Thank you in advance!

I could use some help. I did the WJ brake booster upgrade, but I had a leak at the back of the distribution block. Fluid was coming up out of the top of the rear fitting. Pulled everything out again, took a new set of lines to my mechanic--thinking maybe my lack of experience in making double flares was the problem--and put everything back in. Today I went out to bleed the brakes and finish the job when I noticed that fluid was already coming out of the rear fitting again, without ever having depressed the brake pedal. The line is new again and the brake line fitting is new again. Could it be my distribution block (or is it called a front proportioning valve)? If something is gummed up, can I fix it so the double flare seats right again? Or do I need to find a replacement block? Maybe there some other answer? Appreciate everyone on this site. It's been a huge help.

I recently finished doing an 8.8 SOA swap in my 1991 Jeep comanche Pioneer 4.0 manual. I need to do something about the brakes because they are seriously lacking in stopping power. Currently all I have done is eliminated the rear proportioning valve. I am going to swap in a 95/96 XJ brake booster, master cylinder and proportioning valve. My question is seeing that the 8.8 has disc brakes do I need to find a brake booster, master cylinder and prop valve from a donor vehicle that also has disk brakes or will a donor with drums work? What would be the best set up to keep the rears from locking up before the fronts under extreme braking conditions? Thanks in advance.

I have a 1988 jeep comanche and i can't get the air out of the brake lines i put new ones on and i get brake fluid out of the lines but no air but the peddle is still soft and their are no leaks what do i do

I noticed a few days ago my brake lights have not been working for some reason. But I have taillights or running lights (whichever you prefer) and they are nice and bright. I have been over the sockets in the back before I had inspection a 6 months ago and cleaned them all up to make sure I was getting good connections. they worked really nice up until a few days ago. I only know they stopped working because I always check to make sure they work when I'm driving down the road. not sure why I do that but you never know what weird stuff happens in a Comanche. Anyway hopefully someone can point me in the right direction please. Thanks!

Hi Guys, I'm sure that there's already a post for this, but I couldn't find it.. But Anyways, I've seen pictures, and home made diagrams on how to delete it, but no detailed write ups, or pics.. :???: Any help would be greatly appreciated Thanks!

http://www.rockauto.com/RSS/vehiclefeeds.php?carcode=1181821&m=wc&l=en&html=true

I have a 1989 Jeep Comanche without ABS. It was originally 2-wheel drive, but I began the conversion process by swapping in a front axle from a 1993 Jeep Cherokee with ABS. After that was put and the system bled we went to test it and found we were without brakes. The pedal went to the floor. It could be pumped up without leaking down, but after it was let off for a few seconds, it would again push straight to the floor. We found the proportioning valve was stuck, so it was replaced along with the weak, old master cylinder. The height-sensing system in the back was eliminated by running a new hard line. Also, the front axle was equipped with new calipers, rotors, pads, and flex-lines. I have yet to find any leaks, yet the pedal is just the same. Could it be the fact that I am running ABS calipers (which are a bit bigger) on a non-ABS system? Or is it something else??

Hello, I have an 1988 jeep Comanche Eliminator used as a daily driver with an overheating brake problem. I just replaced the front disc with slotted rotors and new pads and also replaced the rear drum shoes to. The brakes work good until you go down hills. When going down hills I can start to feel the brakes fade and then the brake peddle goes to the floor with the truck slowly coming to a stop and I have to pull over because I have no brakes. Even when I pump the brakes that doesn't help ether. I don't ride my brakes and usually use engine braking. I was wondering if my master cylinder is going bad? The brake fluid is not that new but i'm going to bleed the brakes and put new fluid in. I heard that the brake boosters are bad in the 1988 jeeps? is that true or not? Any advise needed, Thanks.

Large list of parts for the MJ. Heavy on brake parts but lot s of other stuff too. http://www.rockauto.com/RSS/vehiclefeeds.php?carcode=1181821&m=wc&l=en&html=true

I have a dana 35 rear end right now and i am currently redoing all my brake lines after this past winter the negative 30 days were cold enough to burst my brake line. i figure since I'm going through all this work i might aswell convert my rear brake drums to disk brakes. I know some of the grand cherokees later came with rear disk brakes i just want to know what all do i need to grab from the grand cherokee at a junk yard to convert them I'll end up buying brand new calipers and rotors and pads from the store but i still need all the mounting hardware. any suggestions or advice from anyone who has done this?

hey guys i am looking at getting a 3 in rough country lift for my comanche and i wanted to know if i should buy extended brake lines bc i want to replace them anyway. does anyone have a preference of whom they get it from and or what size. thanks brady

I HAVE A FORD 8.8 3.55 DISC BRAKES IN THE BACK. I'm LOOKING TO START ON THE FRONT ANY SIGGESTIONS ON A GOOD AXLE?

OK - I know this horse was turned into glue long ago, but I just want to be sure: On the MJ distribution block, the port you plug to eliminate the rear height sensing valve is the one on the nose of the block, right? and the one on the bottom front is to be plumbed directly into the lines from the rear axle? So many threads have come and gone ion this, and many pictures have been removed. There is no 'clear' picture of the entire system (as did exist some time ago). Thanks!

So I was attempting to do a simple brake job on a 2009 town and country for a friend and I could not believe how hard the back brakes were. The issue I was having was not being able to push the piston back in the caliper. I tried a C-clamp, prying it, loosening the bleeder screw then trying both again. Nothing. That piston was not moving. I was scratching my head on this one. So I thought Id do a little research.... Comes to find out that modern technology has changed a few things. The back brakes are disc brakes on this van but for a safety feature when the hydraulic system fails, the mechanical emergency brakes still work. How the mechanical brakes works is when the emergency brakes are applied, the pedal pulls the cable which then TURNS and PUSHES the piston outward to compress the brakes. So to re-compress the piston, you need a special calpier piston tool you can get from the auto part store that turns and pushes the piston back in. I have NEVER heard of this before and thought id share with you guys.

I searched through 3 pages of stuff and didnt really find out what I exactly needed to know. I got a brake booster and master cylinder from a buddy that was parting out a 99 XJ. What all is entailed to swap it with the old crap in my 89?