clarkerussell

Hello all, I'm trying to refresh the cooling system in my 1988 4.0 MJ and convert to an open system in the process. I have almost everything out, but I can't get the radiator header off because the two nuts that hold the upper radiator isolators are spinning with the bolt that is below it. Is there a trick to it or something? I am thinking I'll need to use a dremel and perhaps cut a slot in the slightly protruding bolt. Then I could use a box wrench on the nut and use a flat head screwdriver to hold the bolt in position. Any thoughts? Clarke

Well, after tearing out many, many parts, I finally found the water intrusion point. It's in the body seam directly under the main fusebox wire harness connector in the engine bay. I have purchased some 3M clear body seam sealer and will be attacking it tomorrow. Since I have a huge tube of the stuff, what other seams should I look at doing at the same time? I'm assuning I should look at the same seam on the passenger side, right? Anywhere else I need to pay attention to? Thanks. Clarke

It looks like the Cab Floor Reinforcement WAS available as a separate item, but it's NLA from Jeep... Does anyone know where part number 5700 0894 (#9 on the picture below) can be purchased?

OK, so my roller pin Master Cylinder showed up yesterday, and it will mount just fine. The only problem is that the line I have running from my slave to the master is not correct. The newer master cylinders use a bottom mounted hydraulic line while the old one comes out of the top. Also, it does not look like the line is available from anyone, even the dealer. The only way to get the line is as a complete kit with master/slave/line as one unit. That's $200 at the dealer... Is there a different line that can use to route to the slave, or should I just buck up and either fabricate the mount or just buy the kit? Thanks in advance. Clarke

Thanks for the help guys, after reading the above post, I think I'm going to tackle this with the help of a friend. I am planning on getting one of the floor boards from eBay, but I don't know what to do about the reinforcement piece that forms a cross on top of the pan. It does not look like that's included with the replacement pan and mine is pretty rusted in the front half. Any ideas? Clarke I think alot of people use C channel to make those and weld studs on to mount the seat too. I think the support where the seat is installed is fine, it's just the part that runs down the middle that's in front of the cross member that is the problem.

Thanks for the help guys, after reading the above post, I think I'm going to tackle this with the help of a friend. I am planning on getting one of the floor boards from eBay, but I don't know what to do about the reinforcement piece that forms a cross on top of the pan. It does not look like that's included with the replacement pan and mine is pretty rusted in the front half. Any ideas? Clarke

Well, the master cylinder I had was an OEM part with the hose already attached, but not attached to the slave. The NV3550 I got at the junk yard came with the slave, but the line was clipped. I had to remove the old line (2" or so), and then the new line just clipped on. SO, the only reason I'm looking into this is to avoind the cutting/welding/fabrication of a bracket to adapt the newer Master Cylinder to the MJ firewall holes. If I can just use an older Master with the existing slave, I'll go that route, I just don't know how to connect the master to the slave or if it's even possible due to fluid volumes, etc. Clarke OK, so the new master cylinder does use the newer plastic lines, but now I can't find a place to buy the line itself. The one I have is for the newer Master Cylinder and it attached to the bottom of the cylinder instead of the top. I guess I'll have to call the dealer tomorrow to see what can be done. It is not possible to connect an older master to a newer line(at least not without some real work) All the masters from something like 1993 on are the same plastic style with the roll pin. Any of those will work. The older metal types cannot easily be adapted. And I'm assuming the 1993-1996 master cylinder has the same mounting points as the older style Master Cylinder, right? If so, I might be able to salvage this! I just need to get a 1993-1996 Master and take a look. That's a lot easier than buying a welder and fabricating my adapter...

Well, the master cylinder I had was an OEM part with the hose already attached, but not attached to the slave. The NV3550 I got at the junk yard came with the slave, but the line was clipped. I had to remove the old line (2" or so), and then the new line just clipped on. SO, the only reason I'm looking into this is to avoind the cutting/welding/fabrication of a bracket to adapt the newer Master Cylinder to the MJ firewall holes. If I can just use an older Master with the existing slave, I'll go that route, I just don't know how to connect the master to the slave or if it's even possible due to fluid volumes, etc. Clarke

Guys, Can you use a clutch master cylinder for the AX15 on an NV3550? I know the older master cylinders used rigid lines and hoses and the NV3550 has plastic connectors, but would the master cylinder match up to the slave? Is it even relevant as long as you can get a hydraulic hose from the master to the slave? I'm asking because I'd like to go back to the standard mount slave cylinder that didn't require hacking up my firewall, but I don't know if/how the hoses would connect and if the master cylinder had to "match" the slave. Thanks. Clarke

I agree, at one point the slave cylinder WAS leaking, but I replaced it years ago. The fluid had actually leaked onto the fuse box and melted some of the plastic... Now when I tested it this afternoon (close the hood and run water over on the cowl), I saw water coming from the fuse box... The more I think about it, it COULD be coming from the slave cylinder and THEN drip over the fuse box. I'll dig deeper tomorrow morning. Thanks. Clarke

OK guys, I found the source of my floorboard rot and it's at the fuse box. Rain was coming in under the hood, and running down the outside of the firewall. It would run around the slave cylinder mounting bracket and accumulate on the top of the fusebox wiring harness. It would then just leak into the car... nice... SO, I need to take the fuse box out, but see no easy way of unplugging the loom from the back of the fuse box. Is this possible to do? If so, how? On a similar note, is there a gasket or something that should be there? Thanks. Clarke

OK, I've contacted the eBay guy to see if he'd sell just the drivers side pan. Does anyone know what a fair price to have it welded back in would be? Thanks. Clarke

Well, I started pulling the rubber mat out of my truck to replace it with a new one. Looks like I should have done this much sooner as the driver side floor is rotted out... Crap... I've never had to deal with rust before, but here is what I'm up against. The rust does not extend TOO far up, and the frame rails seem fine. It does NOT extend to the rockers, and it does not go up towards the pedals under the rubber mat in the picture, it stops there. What are the repair options and, since I can't fix this myself, what would should I expect to pay a shop to repair? Thanks in advance. Clarke

Awesome. Thanks for the info!

No AC :) I have a supply of R-12 so I'm not converting yet.

Does anyone know what the R-12 capacity is for a 1988 4.0L?

Guys, When I converted from 4x2 to 4x4, I used an NP242 to get full time 4x4. Unfortunately, I did not get the metal gate under the carpet that helps align the handle. All I had was the one for the NP231 so it's missing the full time notch. Do I need to find a replacement from a Cherokee with full time 4x4, or can I just modify the one I have? Thanks. Clarke

Thanks. The problem that I have is that the hangers are perfectly vertical right now. To get the pipe forward 4 more inches would require me to cut a few inches from the part that attaches to the muffler and then pull the pipe closer to the muffler. That would cause the hangers to be pulled forward, and would raise the tail pipe up as the mount would swing up a bit. It's like the tail pipe needs to have a few inches cut from the straight portion and then weld it back. What a fricking pain... I purchased it to fit, not as a starting point for a fab job.

Well, I finally got the exhaust back on. I used a Flowmaster 50 Series Delta Flow Muffler and a pre-bent Walker tail pipe from Advance Auto Parts. Total cost for muffler, pipe, clamps and paste came to just under $190. After I removed the old pipe that had fused itself to the cat, I only ran into one other issue. The Walker tail pipe was about 4-5 inches too long. Perhaps it was that the Flowmaster was too long, but regardless, I had to cut the tail pipe down to fit. As the part I cut has a slightly reduced diameter, it made for a VERY tight fit into the back of the Flowmaster. I had to wiggle it in and then use a mallet to fully seat the pipe. After it was all done, all the hangers lined up and all seemed good. The only think that worries me is that the tail pipe seems to be pointing up which would keep condensation from draining out. Check out what I mean here: Also, I'm not sure if the tailpipe alignment it where it should be. It seem to me that it should be an inch or two further forward. See the attached pic for it's final placement. Thanks everyone. Clarke P.S.- It sounds very good compared to the rotted out OEM one I had before... virtually no cabin noise, but a good exhaust note outside. For giggles I fired it up without the cat or exhaust. Wow. that was pretty loud... sweet sounding, but loud.

OK, after sawing through the old tail pipe and unbolting the Cat, I had more access to the "weld". After about 30-45 minutes of grinding, pulling, tearing, and cursing, I got the old pipe separated from the cat... whew... Now, I'm about to install the system and there are going to be two slip joints. Do I need to use some sort of paste to make sure the joints are properly sealed? I was planning on using something like this: Thanks in advance. Clarke

I had DW for a while and fixed it with a simple shock swap. Mine were shot and were not dampening the rebound of the wheel. New shocks cured it. By the way, it's scary as hell when it happens on the highway.

Riiiiiiiight... Unfortunately the heat blowing into the cabin is a bit much.

OK, so the one for the 2000 XJ (PN: 5210 4170) is still available, but the one for the 1990 (PN: 5300 5384) is not. Do I need to worry more about matching it to the body, or matching it to the transmission tower? In other words, is the mounting plate the same for all years and only the "hole" the shifter pokes through is different, or is the base different between the 1988 and the 1997+ bodies. Thanks.

I'm in Charlotte, NC. Where are you? crap man, sorry, I havent even checked this thread since I posted I'm in Southern Tn Are you in the Eastern or western part of southern TN?

We're talking about an INNER boot, right? I already have the outer "bellows" boot.