Fan and brake fluid questions

[ehinlein]

Hello

I just purchased an MTVR. Waiting for EUC to clear. Planning on a drive back recovery/adventure CA to MA. Yes, I know I’m taking a risk here. I’m planning on towing Yukon XL behind after driving it out there. At least I’ll have an escape vehicle. Don’t know how many saw this but I’ve got the one where the fan is “non functioning“. I’m assuming these are engaged until air releases fan if not needed then valve controls air. Video is clear. Fan is not rotating at all. Belt is there. You’d think even if clutch trashed that the fan would freewheel a little. All I can think is plastic is sheared off metal center ring. Any other ideas appreciated.

 

[ehinlein]

That was just fan question. Brake fluid was something else. Sorry.

 

[Elijah95]

When truck cranks with no air pressure, fan engages until air builds. How do you know fan isn’t working?


Sent from my iPhone using Tapatalk

 

[ehinlein]

When truck cranks with no air pressure, fan engages until air builds. How do you know fan isn’t working?


Sent from my iPhone using Tapatalk

You can see in video no spin at all with motor running. And I assume not running long. Totally still.

 

[simp5782]

Does the function check video in the cab show the air pressure ? They do that before they do the under hood start or running video

 

[ehinlein]

This is just a still. Can’t tell for sure but possibly offset from center? Meaning sheared .

 

[MTVR]

Brake fluid?

 

[simp5782]

There was a fan on ebay for sale.

I think I have 1 or 2 in my stash

 

[ehinlein]

There was a fan on ebay for sale.

I think I have 1 or 2 in my stash

I picked a fan up just in case. For those wondering The brake fluid was for a diff post. Beer and posting. . Was wondering what typically in unimog FLU419. DOT 5 or 3. Realized I can just test myself.

 

[ehinlein]

Replying to air pressure question. Yes air pressure looks in good range. My take would be that no air would leave fan locked and spinning anyway.

 

[Nomadic]

Looking at the pic on the lower right (near the Gov Planet logo) it looks like a serpentine pulley. Near the fan it looks like another pulley. Maybe a belt is missing from the fan?

 

[MTVR]

Looking at the pic on the lower right (near the Gov Planet logo) it looks like a serpentine pulley. Near the fan it looks like another pulley. Maybe a belt is missing from the fan?

He's probably gonna need a belt on there if he's gonna try driving it...

 

[ehinlein]

He's probably gonna need a belt on there if he's gonna try driving it...

You are correct. I does look like that lower pulley is without belt. Can’t really tell if there’s one on fan but it sure seems likely belt related.

 

[ehinlein]

You are correct. I does look like that lower pulley is without belt. Can’t really tell if there’s one on fan but it sure seems likely belt related.

And now I see there’s only one belt so.... Hopefully something catastrophic didn’t snap the belt.

 

[Elijah95]

Dust indicates a Cali truck, I’d bank on the belt being dry rotted and maybe popped. Hope no one over heated it c12s absolutely will not tolerate any overheating they’ll crack the head and sometimes blow a head gasket


Sent from my iPhone using Tapatalk

 

[MTVR]

You are correct. I does look like that lower pulley is without belt. Can’t really tell if there’s one on fan but it sure seems likely belt related.

Let's hope nobody cooked the engine with no coolant pumping...

 

[JonM934]

The engine has protection from over heating. It will shut itself down.

The other thing that would stop the fan is the fan off switch in the cab.

 

[Elijah95]

The engine has protection from over heating. It will shut itself down.

The other thing that would stop the fan is the fan off switch in the cab.

I don’t believe this is correct, the military wants equipment to function even when in poor condition to do so. Such as they wouldn’t want an armored MTVR to shut down from a blown radiator when retreating from a combat zone with a bed full of wounded etc condemning them.

I’m still diagnosing my AC cooling fan input and one of the things I did was using a series of resistors and potentiometers to test my gauge and ECM in accuracy of readings, truck was truly at 190° but I was able to simulate 270° input to the ECM and the truck remained running. 270° would ultimately be a complete melt down in truth


Sent from my iPhone using Tapatalk

 

[JonM934]

I don’t believe this is correct, the military wants equipment to function even when in poor condition to do so. Such as they wouldn’t want an armored MTVR to shut down from a blown radiator when retreating from a combat zone with a bed full of wounded etc condemning them.

I’m still diagnosing my AC cooling fan input and one of the things I did was using a series of resistors and potentiometers to test my gauge and ECM in accuracy of readings, truck was truly at 190° but I was able to simulate 270° input to the ECM and the truck remained running. 270° would ultimately be a complete melt down in truth


Sent from my iPhone using Tapatalk

Elijah,

I checked the Cat engine manual and it states the the engine will shut down. Now, you might be correct and perhaps the Marines disabled that feature. I don't think they did because Cat would not warranty an engine with the over heat shut down disabled and I know the government got a warranty on the trucks.

I am curious about your fooling the ECM as far as operating temperature. If you really did simulate an over heat, then alarms would have gone off in the cab and trouble codes would have been logged in the ECM. Were you able to clear the codes? I wonder if engine over heat codes could be cleared?

Jon