CTIS disconnect

[leenigen]

This seems easy but how do I remove a tire? I can disconnect the ctis by slididng it out a little but I can't move it more than that. The right front comes off all the way but air rushes out (from the tire side) so bad that I put it back together pretty quickly. I just need to know how to take a tire off.

[leenigen]

This seems easy but how do I remove a tire? I can disconnect the ctis by slididng it out a little but I can't move it more than that. The right front comes off all the way but air rushes out (from the tire side) so bad that I put it back together pretty quickly. I just need to know how to take a tire off.

[Beastmaster]

There's various CTIS valves and assemblies that you can find. We need to identify which one.

If you have the stock CTIS assemblies, you need to:

1) Ensure that your CTIS is set to the "neutral" position. This means that on the manual selector ones (a knob based selector), it's set to off or none, and on the switch settings, it's set to the middle posititon.

2) Go to each tire, and pop the CTIS tab. It will move away from the spindle by about 1/4". This will isolate the air from each other. Take a 5/8" socket and remove the CTIS covers.

3) On the tire you're changing, take a 3/4" wrench, and remove the CTIS disconnect fitting. Be careful and do NOT bend the tab.

4) Loosen (and do not remove) the 8 lug nuts.

5) Jack up the truck

6) Remove the remaining lug nuts

7) Remove the tire.

The second type is a CTIS quick disconnect that does NOT isolate the tire on the opposite side. You need to:

1) Isolate and disconnect the CTIS line on one side.

2) Isolate the tire on the other side by disconnecting the CTIS line.

3) Jack up the truck, remove the lug nuts, remove tire.

The third type (and the most popular) is the GT/Cepek style CTIS disconnect. This will isolate each tire by itself when you disconnect it. You need to:

1) Disconnect one tire

2) Jack up the truck

3) Remove the lug nuts, remove the tire.

It sounds like you have the stock CTIS lines.

Hope this helps,
Steve

[leenigen]

I have the stock ctis ('94).
What do you mean in step 3 when you say remove the ctis disconnect fittings? Which part gets unthreaded?

[Beastmaster]

The CTIS fitting on a stock setup looks like this:



Unlike most other air type fittings, all this fitting does when you trip it is disconnects the tire from the rest of the air pathway.

You then unscrew the entire assembly off of the spindle. You don't remove the tube from the spindle, you literally unscrew the entire assembly off of it.

Another set of directions can be found here:
http://www.humvee.net/hid/tire/changing.html

[leenigen]

It appears that I have other problems besides figuring out how to disconnect each wheel. Your advise worked great on the rear wheels but I have problems with the front. Even with the wheel selector switch in the off position the front leaks air when I get most of the way unthreaded from the hub (the tires go flat). I think the disconnect on the right front is to blame. Its slightly different than the rest in the fact that the hex head threaded into the hub is significantly smaller that the others and when I push in the tab to disconnect the wheel fron the system it easily pops all the way off (but can stop half way like the others if I manually pull the tab back up). Otherwise it looks the same though. Any ideas why I can't remove the front wheels? The right front appears to leak air into the system even when "disconnected", although that is just my idea, it may be another problem.

[Beastmaster]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by leenigen:
It appears that I have other problems besides figuring out how to disconnect each wheel. Your advise worked great on the rear wheels but I have problems with the front. Even with the wheel selector switch in the off position the front leaks air when I get most of the way unthreaded from the hub (the tires go flat). I think the disconnect on the right front is to blame. Its slightly different than the rest in the fact that the hex head threaded into the hub is significantly smaller that the others and when I push in the tab to disconnect the wheel fron the system it easily pops all the way off (but can stop half way like the others if I manually pull the tab back up). Otherwise it looks the same though. Any ideas why I can't remove the front wheels? The right front appears to leak air into the system even when "disconnected", although that is just my idea, it may be another problem. </div></BLOCKQUOTE>

It sounds like that end is broken.

I'd highly recommend going with the Cepek/GT CTIS lines. They do cost a bit (400 bucks) but they are worth every penny. This way, you can isolate single wheels and not worry about crap like what you're going through.

[leenigen]

Due to the cost of new lines I went to McMaster Carr and built my own disconnect. It works great and only cost $28. I may upgrade all four tires so that I can do away with having to unthread the CTIS before removing a tire.

[Michael A]

Got any part #'s on the home made kit? I'd be interested in seeing what they look like and to know how there working for you so far.

[leenigen]

Go to the HID here for a parts list.
http://www.humvee.net/hid/tire/homectis.html
Some of these part numbers are out of date and the prices aren't correct but the McMaster Carr web page is real good about giving alternatives. I love the one I built. Instead of popping part way out it comes all the way apart when disconnected which makes tire removal real easy. I drive with it disconnected most of the time and have no problems with is being entirely seperated from the center (spindle line). For the price its deffinitly worth it.

[leenigen]

I forgot to mention that in that part list #1 (the elbow)was changed. McMaster Carr suggested an alternative that works fine but is round instead of square. Because of the shape I was not able to drill/tap and add the air valve (part #4). Everything still works fine and as long as the compressor works the air valve isn't too important anyway.