Hmmwv fan clutch leak

[Dayron84]

Good morning. New guy here. Just purchased a 94 m998. Seems to be in overall good mechanical condition but I am still learning how works. I have tracked down a power steering leak to my fan clutch. Ive done quite a bit of research on this site and others and still am not clear on exactly how these work. The fan does constantly spin when the engine is running but this seems to be normal from what I’ve read. I did pull the line from the Cadillac valve and apply 100 psi of air pressure. The fan did slide forward slightly but did not rotate. Since I’ve had it the engine temp hasn’t gotten above 180-190 range and it’s cool weather so it might not be warm enough for it to kick on. It’s not leaking a lot of fluid just a few drops after driving for a while. It’s not clear if the leak is coming from the hose fitting or the clutch assembly itself. Just looking for some advice from those of you that have had this problem. I don’t want to pull radiator and dive into this if I don’t need to. Thanks



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[86humv]

Fluid is only in part circled red, ....theres a seal or fitting that could leak.

 

[Dayron84]

Fluid is only in part circled red, ....theres a seal or fitting that could leak.

Understood. Just not sure if I need to replace the clutch due to a small leak.


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[Dayron84]

I think I’m going to go ahead and pull radiator and replace the clutch and take care of other maintenance items while I’ve got it apart. Does anyone have a good source for a new clutch? Looks like eBay has a few. Fairly expensive. I plan on replacing the serpentine belt, all radiator hoses, and inspecting everything closely. Any other recommendations for maintenance I should take care of? Don’t want to have to do this again for a long time


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[Milcommoguy]

Once you peel back the radiator stack, you have to ask your self... Do I feel lucky? Not having any history and mileage may not count to " What's next to go out?"

Having the "stack" out of the way opens up a window to many of the hard to get at parts. You are right ! This would be the time to Check, Repair, Remove, Replace and Check again. Check-check and double check.

IMO, I would be looking at rebuilding clutch (kit cheap) and add QDC ?
Correct new water pump and anything having to do with cooling
Careful check of vibration damper
Anything that spins or turns or pumps or flows or clamps and clips gets a GOOD looking at.
Add in flush, fluids, fill, cap, torque and check
There a lot to eyeball with the hood and stack out of the way. All things mechanical and electrical

It's really hard to say, do this or that. How big is budget, timeline? What do you want to have in the end. (not another headache or heartache for sure)

Get and study the TM's getting a feel of what's going on and how to put it back on.

At this point you're in pretty deep and time to get it right when easiest, CAMO

GOOD LUCK.

Check everything and more>

 

[Dayron84]

Here we go!


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[Andyrv6av8r]

Mine was leaking a few drops from the QD fitting on the hose at the clutch. I replaced it from underneath witout removing anything and all is well now.

 

[papakb]

I went out and bought a nice Aeroquip quick disconnect to put into the truck and then thought about it for a while. How often do you need to disconnect the fan hydraulic line? I know it's a pain to work on but I thought some nice aircraft fittings would be a better option and went that route. There are hoses and fittings all over because of the aircraft industry and they're cheap. Now I have fittings that don't leak and no hose clamps!

 

[Dayron84]

I plan to go ahead and replace water pump while I’ve got easy access. It’s been a while since I’ve done a water pump. Any suggestions as to gasket? Use paper gasket or rtv? Whatever I do I want to make darn sure it doesn’t leak...obviously


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[86humv]

I plan to go ahead and replace water pump while I’ve got easy access. It’s been a while since I’ve done a water pump. Any suggestions as to gasket? Use paper gasket or rtv? Whatever I do I want to make darn sure it doesn’t leak...obviously


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Make sure you order the right water pump...as there are two types.....6.2 and 6.5 de-tuned use same one....and then 6.5 NA and turbo use same one.
They come with gaskets.

 

[missionexpert]

I plan to go ahead and replace water pump while I’ve got easy access. It’s been a while since I’ve done a water pump. Any suggestions as to gasket? Use paper gasket or rtv? Whatever I do I want to make darn sure it doesn’t leak...obviously

I used a gasket sealant because the gasket the pump came with was already ripped or more likely when removing it from the plastic wrap I broke it.

 

[Dayron84]

Still trying to bleed the power steering after putting everything back together. I have done the wheel lock to lock with engine off and front end raised off the ground 40-50 times. Still have a little whining coming the the steering. I have the newer style reservoir that is on top of the engine with the sight glass on the side. The filler cap is missing the screw that goes in sideways ( not sure what the purpose of that is ). Could the system be sucking air through that small hole? I’ve checked everything else for leaks and all is dry.


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[86humv]

Its not a screw...Its for a small fitting for a hose to the vent / fording system.

 

[Dayron84]

Its not a screw...Its for a small fitting for a hose to the vent / fording system.

So is it okay to just leave it open or does the cap need to be replaced?


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[Dayron84]

Anyone know if this makes a difference? I’m still having a hard time getting PS bled and wandering if it’s sucking air through this hole. I also installed an inline trans filter when I was replacing all the hoses not sure if that could have any effect on getting the system bled properly


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[kunland]

Mine was leaking a few drops from the QD fitting on the hose at the clutch. I replaced it from underneath without removing anything and all is well now.

How did you remove that part? Did you have to take out the whole hose? Mine is leaking from that area. Hoping not to pull the radiator stack to fix the leak. Any other tips for dealing with leakage from that area? Thanks!

 

[Andyrv6av8r]

As stated above, disconnected QD fitting, dropped the end down and changed it underneath

 

[HoveringHMMWV]

And then to help reconnect the QD fitting, make one of these tools.....

Fan Clutch Quick Disconnect "Reconnect" Tool

Offering up this idea for those in need. I made several attempts using different methods to get the coupling reconnected. All were unsuccessful because of the tight space. So, I made a coupling tool or key to insert before pressing the two halves together. Once pressed together, the key was...

www.steelsoldiers.com

- HoveringHMMWV

 

[Milcommoguy]

Another "What were they thinking" moment with the HumV.

QC definitely better than messing with the fitting when time to change a belt. One never forgets the taste of dirt, dust mixed with ATF....LOL

My two cents on PS purging. In a hurry and If it foams up, give it a break. Let it settle out (ten minutes or more if it blew out everywhere, keeping the RPM's down.

Another, I have a bleeder (like on a brake cylinder) off the Cadillac valve. Pop a 1/4 inch hose on it back to the pump fill tank and go easy.

Foam and fun, CAMO

 

[kunland]

As stated above, disconnected QD fitting, dropped the end down and changed it underneath

Thank you, I appreciate your help.