Fuse panel replacement

[LoTGoD]

Of course this has to happen right when winter rears its ugly head here in NE Ohio....

 

I was having intermittent heater, turn signal, and horn issues since I picked the MJ up in July. Of course I didn't need the heater at all until the month or so. I figured the blinkers out...bad fuse. The horn still doesn't work.

 

Saturday morning I was on my way to get some delicious Dunkin Donuts coffee, when the whole cab suddenly smelled like burnt clutch or hot brakes. I pulled it off the side of the road and found the 25A fuse for the blower motor was fried inside the fuse panel. I pulled it out, and everything was still running ok.

 

So after all that, and searching on here, I check the master cylinder, and sure enough, its leaking. I pulled the 2 screws off on Saturday night, and used some non-chlorinated brake parts cleaner to soak the whole fuse panel down. I let it all dry, and installed a new fuse in the blower slot. About 3 minutes in to the 5 minute drive home, I smelled the same burnt electrical smell that I did earlier in the afternoon.

 

That's where I am now. I am going to replace the master cylinder, and use DOT-5 fluid in it after the change. The fuse panel is what is confusing me. I see all you guys talking about replacing it, but how are you doing it? Cutting each wire one at a time, and soldering it to a new panel? Removing each wire from the internal clips and pusing it in to a new panel? I am fairly handy at soldering, but the angle under the dash and fat butt don't mix too well. I was hoping there was something I was missing, so any help would be appreciated.

[mvusse]

DOT 5 fluid is silicone based and not compatible with any system not meant for DOT 5. Use DOT 3 or DOT 4. Yeas, DOT 5 should not dissolve plastic, but it might cause other issues since the system was not designed to run with it. It's like trying to use transmission fluid in your brake lines.

[james750]

It depends on if it is your brake or clutch master? If it is your brake master, and you do not have ABS brakes, DOT 5 will be compatable with any brake fluid you have in their now. DOT regulates the fluid b/c all of them must be compatable and not damage the braking system. The reason why DOT 5 cannot be used in ABS braking systems is because it has silicone in it, and when agitated, DOT 5 will release air into the system. If it is a clutch master, I don't think that DOT 5 can be used at all.

[mvusse]

DOT 5 compresses more than DOT 4 which is not a good thing. I also does not lubricate like glycol based fluids (like DOT 3/4), which is why it can't be used in ABS systems, as the valving needs to be lubricated. DOT 5 also aerates easily (forms bubbles and becomes foamy), which is a REALLY bad thing. The only 2 goof things are the higher boiling point, which should not really make a difference unless drive a race car, and it doesn't dissolve plastic.

[LoTGoD]

Ok, so now you guys have me confused. Eagle stated in one of the fuse panel threads that he has changed his clutch master fluid over to DOT-5. Did I read that completely wrong?

 

See here --> viewtopic.php?f=2&t=12594

[Eagle]

DOT 5 fluid is silicone based and not compatible with any system not meant for DOT 5. Use DOT 3 or DOT 4. Yeas, DOT 5 should not dissolve plastic, but it might cause other issues since the system was not designed to run with it. It's like trying to use transmission fluid in your brake lines.

DOT 5 is made as brake & clutch fluid. It is completely compatible with DOT 3 and DOT 4 fluids. It won't mix with them, so if you have both fluids in one system they'll be completely stratified and separate, but they'll coexist happily for years. The reason not to do that is, once you put any DOT 3 or DOT 4 in with the silicone, you lose all the non-hygroscopic advantages of the silicone.

 

The U.S. Army has used nothing but DOT 5 silicone for brakes and clutches in military vehicles for something like 25 years. I use only DOT 5 silicone in the brakes and clutch system of my XJs and MJs, and I haven't had any problems whatsoever. I started using it in my race cars about 35 years ago, before I even bought my first XJ. I won't use anything else in a Jeep I intend to keep.

 

The only caveat is that you should NOT use silicone in an ABS system. There are so many different reasons given that I won't even get into it. Chrysler engineers can't tell me why -- they think it comes from the siicone manufacturers. And Dupont engineers can't tell me why -- they think it comes from the car manufacturers. The only thing they agree on is, don't use it in ABS. Fortunately for me, I don't own anything with ABS so it's a non-issue for me, but I have to pass it along when I recommend silicone brake fluid to everyone else.

[LoTGoD]

Excellent post Eagle! Thanks for clearing that up!

 

Ok...now back to the original thread...

 

How do I go about replacing the fuse panel?

[robfg67]

I'd be interested in knowing how to replace the fuse box too. Some of the contacts in my box are failing. Has anyone does this before?

[bermsurfer230]

:agree: Me too! Might be the cause of some of my wiring issues, and maybe why my ignintion seems to cut out a little here and there, and make starting the engine hard somedays.

[watchamakalit]

:agree:

Sign me up. Sounds like someone needs to do a writeup.....

[jtdesigns]

I replaced alot of the fuse connectors in my fuse box... It was pretty straight froward, but kinda a PITA deal, cause you can't pull the fuse box out very far. You have to get on your knees and stick our head under the dash. I had the help of a really small flat head screwdriver and a small hook set, to push the old connectors out. If you want, I can get you guys a picture tomorrow of what the connectors look like, so to better arm yourselves with what your dealing with. I'm not sure if you can source aftermarket connectors. I bought a whole dash harness from a member here. Then I swapped some, and cleaned some of the connectors.

[carnuck]

On my old Cherokee I cut out the offending fuse connectors and put an inline fuse it it's place. I use Castrol GTLMA fluid in my brakes, but especially in the clutch cyls of these rigs (older ones even state so on the lid)

 

ABS can't use DOT5 because it has no lubricant for the computer valves, which causes them to score the bore and bind up (resulting in suddenly having no brakes)

 

 

ASE and NHTSA both say do NOT mix DOT5 with other fluids (it even says so on the bottles) DOT5 is silicon based and the Dot3/4 is veggie oil based.

[Eagle]

ASE and NHTSA both say do NOT mix DOT5 with other fluids (it even says so on the bottles) DOT5 is silicon based and the Dot3/4 is veggie oil based.

DOT 3 and DOT 4 is glycol-based. I don't think that's a veggie oil, but I'm not a chemist, so I don't know.

 

It is physically impossible to "mix" silicone brake fluid with glycol-based brake fluid. The operative word for mixing two fluids is "miscible," and the two types ain't miscible. It's like pouring oil into a glass of water. Shake it up enough and you'll get globules of oil dispersed throughout the water, but they aren't "mixed" and, if you let it settle, eventually the oil all floats to the top in a separate layer.

 

Same with DOT 5 and the glycol brake fluids. There is no chemical reaction. You can fill a small container partially with DOT 3 and/or DOT 4 and then pour some DOT 5 into the glass. Nothing will happen. Come back after letting it sit for an hour, and it'll be completely stratified. But, any time there's glycol fluid in the system, that fluid is hygroscopic (attracts and holds moisture vapor), and one of the primary reasons for using silicone is that it is NOT hygroscopic. So combining (I won't say "mixing") the two in the same system defeats the purpose of spending the extra money for the silicone.

[jaekl]

While we are on the subject of brake fluid and its hydroscopic nature. It has been stated that it actually pulls the moisture out of the air. The problem is saturation point. Like the atmosphere it will have a dew point defined by some parameters. The water will condense and fall out. If that lower surface is steel, it will rust. The hydroscopic nature is why the fluid should be changed. The higher the moisture content, I'm sure the boiling point of the fluid is also lower as the water turns to steam and you get a spongy pedal. The rust is just a nuisance. (On another car I have the master cylinder is the only horizontal cylinder with the reservoir directly above it. A rust pit forms directly below the port to the reservoir.)

 

 

PS. Do I change my fluid? No. Except for changing the front hoses a few years back and now the rear hose and lines on the axle, I still have 22 year old original fluid, well maybe 50% after the bleeds. The other car has had Dot 5 for over twenty years and it looks like it is time to rebuild the system. Probably more from the lack of use than age.

 

As for the fuse panel, 3 things, location, location, location. There won't be any easy way to do it with the short wires between the bulkhead connector (C100 or C101) and the panel. Having a 2 foot lift kit would make it easy on your knees. Pulling the contacts doesn't look easy and besides some might even be broken, mine are. So splicing each wire on both ends will be the last resort. In lines fuse are possible but could be a mess and an identification issue. You could also consider a panel from another type of car and locate it more convient. There is no easy answer for a badly corroded panel except splicing one at a time. Hopefully, you don't have many options so you don't have to to al of them.

[LoTGoD]

I ended up swapping out the clutch master with a new one from Crown. Seems to be new, and not a reman. I bled all the old fluid out first using a vacuum pump. Didn't spill more than a drop or two. I got the new MC in, and bled through half a bottle of DOT-5. I had a good, firm pedal, so I figured it was done!

 

I pulled the 25A blower motor fuse link side off the block, and moved it over to where the rear wiper 25A fuse goes. Now I have heat!! Other than no horn, all the rest of the electrical stuff is working fine. The DOT-3 did a real number on the firewall...

[carnuck]

Castrol GTLMA is low moisture absorptive 3/4 designed for ABS systems. The glycerol comes from Soy Beans and olives IIRC. (at least it did back in the Stone Ages when I started working on cars)

 

 

http://en.wikipedia.org/wiki/Brake_fluid