CTIS - why so finicky ?

[1Ghost]

Hello :
Looking at the m923 m928 .
Why does it seem that so many 5 tons have non operational CTIS ?
From what I have read many people put the delete plugs in the wheels and remove or turn off the system .
I believe it must be the transfer from the axle mount to the wheel ?
I have looked at the CTIS info on here but still not sure how the plumbing actually does this .
I know of outside lines that run to the center of the hub .

Any pics , etc would help , I would like an operating ctis system or ability to fix it .

MPG is 10 ? or so ?

Top speed about 65 on the big singles ?
Is the HP at 250 enough power or did you turn yours up a bit ?

thank you

 

[simp5782]

CTIS works great if you know how to properly diagnose issues with them and parts are readily available. Unfortunately some parts aren't available and the surplus people who control alot of the market have high prices on the parts making it not so cost effective to repair the system. I mean you don't really need your tire pressure checked all the time. it is nice to be able to push a button and air down but how often do you do that? with its a mall crusier for most people

Plus I run 75psi in the front and 60psi in the back. Cant really do that with CTIS. IMO it gives my truck a better ride especially empty. I mean i go weeks without checking my tire pressure. If i have a leak I fix it, don't depend on CTIS to air is back up for me. CTIS can be a nightmare. Especially when you go into a store and come out to your truck sitting on 6 flats. It doesn't air the tires back up on startup, so then you air the truck tires up manually, and then the CTIS if you forget to unplug it deflates all the tires again. Trust me you will throw the CTIS controller as far as you can after that happens.

 

[snowtrac nome]

I wouldn't be so quick to bad mouth it mine works fine, even during the winter. Yes I do use mine all the time, I air down when I leave the road I have better traction. I even air down to cc mode when I'm in some of the surrounding villages that never see a grader blade, the ride is better. if it works and you drive off asphalt much you will find your self using it quite a bit.

 

[98G]

And then one fine day you'll be running down the highway at 60mph and the CTIS will decide it's a traction impaired surface and dump the air out of all 6.... bouncy bouncy bouncy. And maybe a sidewall goes boom.

 

[Jbulach]

I also love mine, but my truck spends half it’s life off road, or on “soft” driveways and yards that I want to try not to damage.
Ironically, even the smallest, system air leaks can give CTIS fits, so this is probably the biggest problem that people struggle with.

Yes, the hub seals( maybe what you are referring to as “the transfer from the axle mount to the wheel”) are a potential leak source, and the one thats the biggest pains to fix.

Even though MPG claims all over the spectrum, I think 10mpg is unrealistic for most of us, I believe 6 would be more likely. I’m guessing I could get around 10 or maybe a little better, if I was running a constant 45mph, on flat ground, tires aired up, and truck empty, but my truck will never see those conditions.

65-70 MPH max, is typical at 2100RPM.

Once you learn how to drive the truck the stock power level is fine for it’s intended use. But like anything, we always want more, but more always comes at a price!

CTIS, MPG, tire size, and even power level, all have a lot of personal opinions, so you’ll get a million different answers. Similar to 8.3 vs 250... even though everybody knows the 8.3 is far superior. BOOM!!!

Saw someone with a “Haters going to hate” avatar around here somewhere?

 

[Jbulach]

...Especially when you go into a store and come out to your truck sitting on 6 flats. It doesn't air the tires back up on startup, so then you air the truck tires up manually, and then the CTIS if you forget to unplug it deflates all the tires again. Trust me you will throw the CTIS controller as far as you can after that happens.

Now this... I would love to see a video of, just as long as I’m not the one staring in it!

 

[Coffey1]

The Ctis is a great tool.
They have to be loved and cared for.
Dirt or bad coil in pcu is why some are like a wife you want to divorce. They sit unused for a long time in a yard some where.
Learn the system and it's easy.

 

[kblazer87]

I have only bought three 5 tons from auctions but the ctis has worked good on all three of them.

 

[simp5782]

I also love mine, but my truck spends half it’s life off road, or on “soft” driveways and yards that I want to try not to damage.
Ironically, even the smallest, system air leaks can give CTIS fits, so this is probably the biggest problem that people struggle with.

Yes, the hub seals( maybe what you are referring to as “the transfer from the axle mount to the wheel”) are a potential leak source, and the one thats the biggest pains to fix.

Even though MPG claims all over the spectrum, I think 10mpg is unrealistic for most of us, I believe 6 would be more likely. I’m guessing I could get around 10 or maybe a little better, if I was running a constant 45mph, on flat ground, tires aired up, and truck empty, but my truck will never see those conditions.

65-70 MPH max, is typical at 2100RPM.

Once you learn how to drive the truck the stock power level is fine for it’s intended use. But like anything, we always want more, but more always comes at a price!

CTIS, MPG, tire size, and even power level, all have a lot of personal opinions, so you’ll get a million different answers. Similar to 8.3 vs 250... even though everybody knows the 8.3 is far superior. BOOM!!!

Saw someone with a “Haters going to hate” avatar around here somewhere?

We wont comment on the MPG the old girl gets with a bed full of stuff and no trailer

 

[Jbulach]

We wont comment on the MPG the old girl gets with a bed full of stuff and no trailer

Tease! But I guess you don’t count, with all your... gears.

 

[74M35A2]

It’s flaky because it is almost 30 years old.

It’s flaky because system comprehension is low. It is something new in civilian hands with a low/small knowlesge base to support it. It is not required, so people yank the connector vs take time to understand it.

It’s flaky because it has low robustness. A single “improper” engine shut down in the wrong switch order with the stock military alternator can wipe it out.

It’s flaky because the pressure transducer drifts over time.

It’s flaky because it takes a lot of air pressure and volume to work well as intended. As these old scrap trucks continue to age, their air compressor output falls, leaks develop, and it becomes where the system can’t even initiate at idle.

 

[Coffey1]

Now now it's not that bad.
It's just under standing how it works.
Then it's a piece of cake.

 

[74M35A2]

Love mine. Works perfect. Broke a front valve stem completely off running a car over, CTIS run flat mode kept it fully up the entire drive home. Went flat overnight. Week later put new valve stem in, started the truck, and it fully aired up. I have never put a tire chuck on any of my wheels in 5 years of ownership.

 

[therooster2001]

I have only bought three 5 tons from auctions but the ctis has worked good on all three of them.

"I have only bought three 5 tons from auction". - That's really funny sounding. It's not a race, or is it?

Well, one auction here, and CTIS is wonderful. Never had a hub leak, so maybe that's why. I don't really need it, but then again, we don't need air conditioning either, yet some people have it. Someone commented it's flakey because we don't know too much about it. Totally agreed, it's probably the least documented system we have, even though it's covered in the TM and has a separate manual.

We have some smart people on this forum, some even have or still work for a certain tire inflation company, and have some proprietary info that they share when we got stuck.

Just ask.

Go CTIS!