Fan not running on my M923A2

[Carlo]

Last tuesday my son and I took the M923A2 out to check the snow fall on a closed road mountain pass. Almost arrived at the top and I note the Temp is running up close to 200 F . I opened the hood and the fan was not turning. I remember my M931A1 could be made to turn manually my a bolt but I could not find this on the M923A2.
Is there a switch / sensor that activates the fan clutch?
Thanks Bros!

 

[porkysplace]

The 8.3 motor is a air operated clutch fan.

 

[Carlo]

The 8.3 motor is a air operated clutch fan.

There is a valve or switch that activates the clutch, no? Is there a way I can test it?

 

[porkysplace]

Go to right around post #92 of this thread 2600mile recovery

 

[Carlo]

Go to right around post #92 of this thread 2600mile recovery

Thanks. I know the A1 has this for I had to do this once on my M931A1 but I was not sure the M923A2 had the same set up. Any hints on why mine is not working auto mode?

 

[porkysplace]

Try this thread Actuator, Air Fan Clutch for M923a1 . That other thread is about useless to find anything there are a few threads combined .

 

[Carlo]

Try this thread Actuator, Air Fan Clutch for M923a1 . That other thread is about useless to find anything there are a few threads combined .

I found some photos and will remove it to see if the valve is working. Thanks

 

[goldneagle]

My thermal switch was stuck (too dry). I took it apart and lubed the parts, then reassembled. Works fine now. Some members changed the o-rings on their's.

 

[Carlo]

My thermal switch was stuck (too dry). I took it apart and lubed the parts, then reassembled. Works fine now. Some members changed the o-rings on their's.

Thanks Gold.. It was snowing today but this week spring might be finally here and I will remove it for hopeful repair.

 

[Carlo]

Well I had time to remove this valve and spray some WD40 inside it and it works! That saved me some money and I suggest anyone having the same problem try the same before buying a new one.

 

[Derrickl112]

When the fan on my m939a2 engages, it will not shut off until I drain all of the air from the tanks. It also sounds like something is rattling around in the clutch. Has anyone else had this problem?

 

[Carlo]

When the fan on my m939a2 engages, it will not shut off until I drain all of the air from the tanks. It also sounds like something is rattling around in the clutch. Has anyone else had this problem?

Mine now turns on at 170° and runs till it cools to 160°. Sounds like it wont release. I tried a cheap fix by sparying WD40 down the tube and took the valve apart spraying more WD40 inside it. Has the truck set for long?

 

[goldneagle]

Mine now turns on at 170° and runs till it cools to 160°. Sounds like it wont release. I tried a cheap fix by sparying WD40 down the tube and took the valve apart spraying more WD40 inside it. Has the truck set for long?

I might be wrong but I think it is adjustable. If I remember correctly you can adjust how far in the actual thermal piece goes and lock it in that position. It is on the coolant side of the thermal switch. I think they are supposed to kick on at 180 or 190.

 

[Carlo]

I might be wrong but I think it is adjustable. If I remember correctly you can adjust how far in the actual thermal piece goes and lock it in that position. It is on the coolant side of the thermal switch. I think they are supposed to kick on at 180 or 190.

I agree with you. I see on the back it has something that looks like it could be adjustable. Is there a TM on this?

 

[goldneagle]

I agree with you. I see on the back it has something that looks like it could be adjustable. Is there a TM on this?

I was going to mention that I would adjust the fan to come on at a higher setting. The fan puts a drain on the engine and makes a lot of noise. If you let the thermostat open it can cool the engine without the aid of the fan. The fan should only kick on when the radiator and air flow are not enough to cool the engine. I found that mine only kicked in when sitting in bumper to bumper traffic or under a heavy load. That is the way I observed it in my travel with the M923. It may change later this summer once our temp outside goes into the upper 80's and 90's.