Air Lockers Not Working

[dlynes]

Well, I was wrong. All lockers have air, front axle is the only one that will engage. I guess I'll pull the actuators and look at them. Rig them to apply air on the bench and see if they work.

what was your resolution?

 

[Marquette]

Edit: I’m not looking for help, just adding some things I found and learned today to help others.

I've had this truck for 3 years and the entire diff lock system has worked until now.

Problem:
-One of my trucks will not engage front wheels in any mode, so I looked into it tonight.
-CTIS is off, not in highway mode, and the front wheels don't get any power.

Conclusion:
My locker button works and all 3 red lights work. The first push of the button lights the first red light and sends air to the top line on the transfer case, but the front wheels still won't drive. The solenoid is activating the air valve, but the valve is leaking when open. When the valve is activated and open, the valve leaks through the stem.

1. The air valves have to seat in both the open and closed position, or they will leak.
a. When activated, the valve opens the air inlet, sends air to the work item (transfer case, diff locks, air horn, fan clutch) and closes the air vent. If the air vent doesn't close properly, then the system pressure leaks out of the vent cap.
b. When deactivated, the valve closes the air inlet and opens the vent. If the air inlet valve doesn't close properly, then air leaks out of the same vent cap.
c. If ANYTHING in this entire system is leaking including any of the 6 valves, then the whole system is losing pressure???


Two valves in my system are leaking through the vent cap:
1. Transfer case valve leaks through vent cap only when activated, so it doesn't build full pressure.
2. Horn valve leaks when closed, so it leaks all of the time. I put a piece of plastic under the cap years ago but I found it still slightly leaking tonight.

When I get both replaced, I will report back.

 

[Mullaney]

I've had this truck for 3 years and the entire diff lock system has worked until now.

Problem:
-One of my trucks will not engage front wheels in any mode, so I looked into it tonight.
-CTIS is off, not in highway mode, and the front wheels don't get any power.

Conclusion:
My locker button works and all 3 red lights work. The first push of the button lights the first red light and sends air to the top line on the transfer case, but the front wheels still won't drive. The solenoid is activating the air valve, but the valve is leaking when open. When the valve is activated and open, the valve leaks through the stem.

1. The air valves have to seat in both the open and closed position, or they will leak.
a. When activated, the valve opens the air inlet, sends air to the work item (transfer case, diff locks, air horn, fan clutch) and closes the air vent. If the air vent doesn't close properly, then the system pressure leaks out of the vent cap.
b. When deactivated, the valve closes the air inlet and opens the vent. If the air inlet valve doesn't close properly, then air leaks out of the same vent cap.
c. If ANYTHING in this entire system is leaking including any of the 6 valves, then the whole system is losing pressure???


Two valves in my system are leaking through the vent cap:
1. Transfer case valve leaks through vent cap only when activated, so it doesn't build full pressure.
2. Horn valve leaks when closed, so it leaks all of the time. I put a piece of plastic under the cap years ago but I found it still slightly leaking tonight.

When I get both replaced, I will report back.

.
Sad to say it - but with leaks you are going to have sporadic action.
Maybe hook your truck up to "house air". Maybe you don't have house air. Maybe you can borrow a mobile air compressor? Hook it into the front glad hand and you can hunt your leaks without the truck running...

 

[Marquette]

.
Sad to say it - but with leaks you are going to have sporadic action.
Maybe hook your truck up to "house air". Maybe you don't have house air. Maybe you can borrow a mobile air compressor? Hook it into the front glad hand and you can hunt your leaks without the truck running...

Hey thanks, but I meant to add this info in case somebody was having problems. Especially since someone else had asked for help and didn’t follow up if they had fixed their truck or not.

I found out the electric solenoid air valves have to seal both when they are activated and not activated. My air horn had always leaked through the vent cap but I attempted to seal it by putting a piece of plastic under the cap which mostly worked until I heard some slight hissing today.

And my transfer case control valve was leaking through the vent cap when activated.

Hoping that replacing both of these valves will cure the problem of my secondary green air needle dropping quickly and my transfer case not engaging!

I also think that adding some lubricating oil into these air lines would help the valves slide, since mine are very dry and possibly sticky.