A few ?'s about my new M923A2

[MTMUDRUNNER]

Just picked up my new to me A2 yesterday,(this thing is going to be fun, a few neighbors almost ran off the road looking at it) I hauled it home since it was a 200mi drive. It seems to be in pretty good shape with just a few problems. First the compressor seems to cycle a lot, it goes up to 125psi cuts out and then kicks back in at about 120ish. Also the ctis seemed to be working but as I was driving it home from the shop I noticed that all 5 lights were flashing, when I shut the truck off and start it again just the Hwy light is flashing. When everything is working correctly does the light stay solid or flash? I just printed off TM9-2320-272-23-1. thanks

 

[chadande]

CTIS light will stay on solid when it has reach the correct pressure for all tires. Try airing down right when you start the truck to get them all the same and them back up to HWY.

 

[swbradley1]

A2 what?

 

[MTMUDRUNNER]

a2 what?

m923a2

 

[Suprman]

5 lights flashing means you probably have a fill side leak to atmosphere. The hwy light will flash when you start up until they system has 120psi or so and the ctis sends air to the tires for a quick pressure check.

 

[MTMUDRUNNER]

5 lights flashing means you probably have a fill side leak to atmosphere. The hwy light will flash when you start up until they system has 120psi or so and the ctis sends air to the tires for a quick pressure check.

When I switch from hwy to any other setting I don't hear any clicking sound coming from the valve control I am thinking that this might be the problem. Would there be anything else that would cause it not to click other than it being bad?

 

[Suprman]

When you first start it, does just the hwy light flash? Until the tanks reach 120 psi the system is just waiting. Once the system sees 120psi then it will do a pressure check. If the pressure check fails then you will get fault lights. When the system sends air to do the pressure test, if there is a break in a line or major leak somewhere, the system will see low or no pressure. This triggers the fault. You can have someone sit in the cab and keep pressing the hwy button and the system will do the pressure check and you can listen underneath and by the tires for an air leak. If the system is not sending air for the pressure check you need to see if the system is getting air. There is one air line in and one line out. The one in has a little filter/water drain on it. You can unscrew the filter holder you will have air coming out with the piece off and the truck running. Try these things then let me know if you are still having problems.

 

[MTMUDRUNNER]

When you first start it, does just the hwy light flash? Until the tanks reach 120 psi the system is just waiting. Once the system sees 120psi then it will do a pressure check. If the pressure check fails then you will get fault lights. When the system sends air to do the pressure test, if there is a break in a line or major leak somewhere, the system will see low or no pressure. This triggers the fault. You can have someone sit in the cab and keep pressing the hwy button and the system will do the pressure check and you can listen underneath and by the tires for an air leak. If the system is not sending air for the pressure check you need to see if the system is getting air. There is one air line in and one line out. The one in has a little filter/water drain on it. You can unscrew the filter holder you will have air coming out with the piece off and the truck running. Try these things then let me know if you are still having problems.

I found a few leaks and fixed all of them but one, there is a inline filter under the dash that is leaking out of the bottom drain. I pulled it off and cleaned the rust out of it and reinstalled it, still leaks a little. I think the rubber diaphragm is shot. I don't think it is leaking enough to cause any problems but I cant say for sure. When I first start it just the hwy light flashes even when the psi reaches 130. I cant hear any clicking from the box under the dash no matter what setting I push. What do you think I should do next. Another thing is all the tires seem to hold air, but I don't know what the pressure is in each tire.

 

[Suprman]

You can check the tire pressure in each tire with a manual guage. There is a schrader valve on each wheel valve. If you see no pressure at the wheel valve then there might be schrader valves installed in the stems. There is a pressure sensor that tells the ctis system to come online at around 120psi. Even if you are trying to dump air and lower to pressure the system wont do anything but flash hwy until the pressure switch tells the system that there is 120psi in the air tanks and the ctis does a pressure test to determine tire pressure. You might have a bad pressure switch. There are 3 pressure switches on the tanks, one for each air tank to alert on low air and one for the ctis. Im not sure if its a normally open or closed switch. I would start there you could try disconnecting it or bypassing it and see if the system will do at least a pressure check and then go from there.
Will

 

[MTMUDRUNNER]

You can check the tire pressure in each tire with a manual guage. There is a schrader valve on each wheel valve. If you see no pressure at the wheel valve then there might be schrader valves installed in the stems. There is a pressure sensor that tells the ctis system to come online at around 120psi. Even if you are trying to dump air and lower to pressure the system wont do anything but flash hwy until the pressure switch tells the system that there is 120psi in the air tanks and the ctis does a pressure test to determine tire pressure. You might have a bad pressure switch. There are 3 pressure switches on the tanks, one for each air tank to alert on low air and one for the ctis. Im not sure if its a normally open or closed switch. I would start there you could try disconnecting it or bypassing it and see if the system will do at least a pressure check and then go from there.
Will

I have tried to check the pressure and nothing, can I just unscrew the stem cap and check it I guess if it starts to blow air then there is no Schrader valve. I'll keep working on it and let you know thanks for the help
Wes

 

[BKubu]

It could also be a computer failure. I've had that problem before.

 

[MTMUDRUNNER]

OK I think we are making headway, thanks to every ones help, I bypassed the filter under the dash and the system started checking pressure around 120psi, but the wheels have a Schrader valve in the stem. Will the ctis work with this extra valve or not I am guessing not.

 

[Suprman]

Before you do anything, go to harbor freight and get a big generic o ring kit. Its like 6 bucks and it will make your life much easier. The wheel stems extend out the front and back of the wheel. The back ends are supposed to have schrader valves. I have seen them not screwed in enough in the back and leak slowly. There is a tool to screw them in just hand snug though. Remove the ones in the front of the stems where the ctis hose comes from the wheel valve and go from there. You can use windex to look for leaks.

 

[MTMUDRUNNER]

Before you do anything, go to harbor freight and get a big generic o ring kit. Its like 6 bucks and it will make your life much easier. The wheel stems extend out the front and back of the wheel. The back ends are supposed to have schrader valves. I have seen them not screwed in enough in the back and leak slowly. There is a tool to screw them in just hand snug though. Remove the ones in the front of the stems where the ctis hose comes from the wheel valve and go from there. You can use windex to look for leaks.

I took the valve core out of the stem on all wheels no leaks so far. I can get the tires to deflate from hwy to sand and the light will stay solid on the sand mode but I can't get the tires to inflate from any setting. On the wet tank between the ppv and the tank there is a pressure switch that has been pulled apart and put back together. When I take this apart and push the switch the on the valve the ctis starts trying to cycle but I still can't get the tires to inflate. Does any one know where I can get one of these switches?

 

[Suprman]

It takes some time to reinflate even when driving. You should make sure your governor is set to around 135psi. Post a pic of the switch I might know where to get one.

 

[MTMUDRUNNER]

I had it at about 1500rpm for about 10min and it did not gain any psi, the gov kicks the compressor off at 135 so that is good. I will get a pick up soon thanks

 

[Suprman]

Jump the damaged switch see if the system fills air. If it allows you to lower pressure settings then it does a good pressure check so no major leaks on the fill side which is a good thing.

 

[RetiredNavy]

How come you havent posted pics of the A2 unit at your house?? Been waiting to see it there.

 

[MTMUDRUNNER]

How come you havent posted pics of the A2 unit at your house?? Been waiting to see it there.

I am terrible with computers, I will get the wife to snap some pics and help me post them.

 

[MTMUDRUNNER]

Here is a few pics of the pressure switch (I think that is what it is) and one of the truck I will get some better ones later. It is the switch between the wet tank and the ppv.