HWWMV Overheat Problem Fan Clutch Friction Pads

[avman]

OK, I have read every post on HWWMV overheating problems and found that my fan clutch Hyd, TDU and Fan clutch work fine. The fan moves back and forth when the TDU is disconnected but no engagement of the fan. There is also on power loss so I know it must be slipping on the friction pads.

Has anyone experienced this before? I ordered some new friction pads for the fan clutch to see it that works or am I just wasting my money and time and just need to order a new fan clutch?

Any input on fan clutch friction pads would be great

 

[Retiredwarhorses]

You have not mentioned anything about why you think you truck is overheating. Your truck should not overheat due to a bad fan clutch. That fan clutch defaults to locked on. I seriously doubt the friction pads in the clutch are bad.
what are your overheating symptoms?

 

[avman]

My HMMWV heats up to 240 degrees and it stays there. The fan moves back and forth with the fan control module is unplugged but there is no change in the fan speed.

I have checked about everything. Got the HWWMV a few months ago and replaced the anti freeze, thermostatic, checked the fan control module (timer controller), hyd fan clutch controller, the fan moves in and out when the hyd fan clutch controller power is removed. I have come to the conclusion that the fan is slipping due to the fact that every post I read talks about the loss of power when the fan kicks in. I have also driven the truck with the hyd fan clutch unplugged and still no change in temperature.

This brings me to trouble shooting this down to the fan clutch. Looking a the schematic I saw the friction pads. I assume if these are slipping, then the fan will not speed up to the engine speed.

I have not read any place about these pad and would assume they are there to engage the fan. Just was wondering if anyone has experience with these. I ordered some and they are coming in. Am I wasting my time or should I just spend the money for a new fan clutch.

Let me know

THanks

 

[Retiredwarhorses]

My HMMWV heats up to 240 degrees and it stays there. The fan moves back and forth with the fan control module is unplugged but there is no change in the fan speed.

I have checked about everything. Got the HWWMV a few months ago and replaced the anti freeze, thermostatic, checked the fan control module (timer controller), hyd fan clutch controller, the fan moves in and out when the hyd fan clutch controller power is removed. I have come to the conclusion that the fan is slipping due to the fact that every post I read talks about the loss of power when the fan kicks in. I have also driven the truck with the hyd fan clutch unplugged and still no change in temperature.

This brings me to trouble shooting this down to the fan clutch. Looking a the schematic I saw the friction pads. I assume if these are slipping, then the fan will not speed up to the engine speed.

I have not read any place about these pad and would assume they are there to engage the fan. Just was wondering if anyone has experience with these. I ordered some and they are coming in. Am I wasting my time or should I just spend the money for a new fan clutch.

Let me know

THanks

Sounds like you have done your your home work, carry on....

have you checked the actual coolant temp with a laser thermometer? The gauges are notoriously inaccurate.
also, have you repalced the coolant bottle cap with a new "correct" 15psi.

 

[dilvoy]

The fan is locked and unlocked to the water pump shaft at the front end of the assy, The rear part with the phenolic friction part is there for stabilization and to allow the fan to slip in relation to the water pump shaft without flopping off balance. The fan doesn't stop when de-activated it just spins along with the parasitic friction from the phenolic piece, but it is not driven at that time.

 

[avman]

Good new, replaced the friction pads in the fan and everything is now working. The old friction pad was half the size of the new ones. These were easier to install and only $24 compared to replacing the fan clutch at $250 bucks.

Installed them and pulled the power on the timer controller and you could hear the fan roar to life. Put the power back on and it shut down the fan (just slower)

Thanks for the input

 

[Stonewall]

Great news. Do you have the 6.2 or 6.5? I am just curious if you have a standard part number for the thermostat (rather than the military number). I have a 6.2.

 

[Retiredwarhorses]

The thermostat type depends on the water crossover used, if it's the older 6.2 or the newer type used on the 6.5 NA from GEP. Both type can be used on either engine. Just take the old out and post a pic. Or a pic of the water crossover.
if you have a 6.2, it's most likely a 6.2 crossover. Thermostat NSN 01-146-8006

 

[avman]

I have the 6.2 and don't have the part number. I went to autozone and got one for a 6.2 diesel chevy k2500, year, I think was 1985. The 1988 thermostatic was set for 195 degree and the 1985 one was set for 190 degree. Of course I wanted the lower temp.

 

[Action]

I have the 6.2 and don't have the part number. I went to autozone and got one for a 6.2 diesel chevy k2500, year, I think was 1985. The 1988 thermostatic was set for 195 degree and the 1985 one was set for 190 degree. Of course I wanted the lower temp.

Did you try getting a thermostat for a 1993 H1 first?