Fan assembly leaking

[Kurtshalftrack]

I am new to HMMWVs mechanial issues. My M998 is leaking red fluid (powersteering Fluid?) from the quick release connector valve on the front of the Fan Assembly. It seem the assembly in front of the fan spins freely where the connector attaches. Is this normal, any idea why the quick release would be leaking it appears new. Any ideas would be great.

Thanks,

Kurt

[Kurt Lesser]

The fan solenoid, brakes, and clutch all get their power from the power steering pump. If you are seeing red fluid that's where it's coming from. The coupling on the front of the fan clutch is made to rotate freely and couple hydraulic power to the clutch when the engine is running to actuate it. If you have a quick disconnect on the fan clutch line it was done after the military released the vehicle. It's a good idea because it makes changing the belts much easied but it does introduce another leak point into the system. If the quick disconnects are cheap ones they could be the source of your fluid but it could also be coming from the seals on the rotary union on the clutch itself and running down the line. Rather than mount the disconnects on the clutch it makes more sense to mount them on the other end of the line where the fitting comes through the shroud. This gives them better support and minimizes vibration in the disconnects.

[hummer4x4guy]

I tried the coupling trick on my truck and they were new and leaked after a short time. IMO you are best off to remove the coupling and hook up the hose directly. The few mins of convience you get from the coupling isnt worth the possible large amounts of fluid loss at a not so great time and the inconvience to deal with if it were to be leaking, and you have no spare fluid.

Joel

[Action]

I tried the quick disconnect, and it let fluid out. The fluid hit the fan and sprayed all over the bottom side of the hood.
I think my fault was using air compressor fittings. lol.
Obviously, I went back to the original style.

Jason

[Kurtshalftrack]

I started the engine and watched the fluid spray from the quick release, I can barely get my hands though the fan blades to release the quick release from under the vehicle, is there any way to change back to the one piece hose without take the radiator and shrowd off? If not I may opt to change the quick release rated for high pressure..if such an item exists.

Thanks for the input.

[Kurt Lesser]

There are certainly QDs rated for high pressure. My diesel compression tester has a QD on the adapter that screws into the glow plug hole. I'd check around but I'd be willing to bet that McMaster-Carr or Aircraft Spruce have what you need.

[dunsbr]

I've been running a self sealing QD on my truck for over 2 years with no problems.

but you do have to make sure you have firmly seated the join when reconnecting or it will pop off to the detent and spray fluid.

IIRC, it can be changed without removing the stack etc..
But it is a PITA! and be prepared to have chaffed inner arms from the fan blades!

Cheers

[hummer4x4guy]

I will rent my arms out to do this job to anyone who needs... I work for parts.

Joel

[Hell On Wheels]

Ok G-men,
Sense we are talking about an area I plan on working on, has anybody run into any problems switching the pulleys out on the water pump from 4 to 5 groves? I thought I would ask before I get stuck or end up replacing the water pump because the pulley wouldn’t come off.

I would stay with the factory setup having the lines to the fan clutch. The problem with QD is if any type of dirt gets into or binds the o-ring and spring it sometimes does no lock into place and when you hit a hard enough bump it will tend to disconnect. This is a problem I have experienced with 6V53T and 8V63T engines. Then if too much dirt collects onto the QD they are sometimes impossible to disconnect without hitting with a hammer. This would be very difficult with the fan shroud.

[dunsbr]

I had no problem swapping my truck over from 4 groove to 5 groove waterpump pulley.
It just slipped right off onece all belts and bolts were removed.
The hardest thing was sourcing the 5 groove pulley.

Cheers