Hmmwv fan clutch leak

[Thumper580]

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

Commo.... Question for you. I will be putting on a new fan clutch. Before I bolt it in place do I need to pre fill the nose cup on the clutch and the lines?? Thanks.

 

[Milcommoguy]

Commo.... Question for you. I will be putting on a new fan clutch. Before I bolt it in place do I need to pre fill the nose cup on the clutch and the lines?? Thanks.

I would check it with air and one could drip some ATF down the fitting to find its way to the seals while on the bench.

Pressurize it with rubber tip nozzle tight to fittings. Wear safety glasses. Easy on the release with ATF in there.

Looking / thinking to purge the line? IMO if clutch is good build / new the small amount of air it will work itself out or be part of the action.

Might be overthinking this a bit. CAMO

 

[Thumper580]

I would check it with air and one could drip some ATF down the fitting to find its way to the seals while on the bench.

Pressurize it with rubber tip nozzle View attachment 815797 tight to fittings. Wear safety glasses. Easy on the release with ATF in there.

Looking / thinking to purge the line? IMO if clutch is good build / new the small amount of air it will work itself out or be part of the action.

Might be overthinking this a bit. CAMO

Not to test it.... More about the final install. Filling it with fluid before hooking everything up.

 

[Milcommoguy]

Not to test it.... More about the final install. Filling it with fluid before hooking everything up.

Well, I read on here after all the work of changing a clutch out... it had a leak.
For me, (and I test everything) better on the bench to discover the problem than in the truck IMO.

Again I don't think it matters fluid or air. Any ATF fluid from the Cadillac valve is going to compress the air in the line / clutch to the pressure needed to work releasing the clutch.

Maybe over time some air might seep past the clutch seals or QDC, that's a big maybe and would hope not LOL.

Just not sure how to get a complete purge end to end and never worried about it. Guess one could leave the fitting (not QDC) a bit loose and run truck to leak, shut it down and tighten... Too much work and messy.

The tee and brake bleeder valve fitting off the Cadillac valve might / could assist in getting some air out. Here's a link >> See the pictures for the MOD.

Operative word here is MAY... YR MAY V. Click and read on >

Substitution: Fan Hydraulic System Bleeder – HMMWV Systems

Bolt it up & rocket ON , CAMO

 

[Thumper580]

Is ut your jn

Well, I read on here after all the work of changing a clutch out... it had a leak.
For me, (and I test everything) better on the bench to discover the problem than in the truck IMO.

Again I don't think it matters fluid or air. Any ATF fluid from the Cadillac valve is going to compress the air in the line / clutch to the pressure needed to work releasing the clutch.

Maybe over time some air might seep past the clutch seals or QDC, that's a big maybe and would hope not LOL.

Just not sure how to get a complete purge end to end and never worried about it. Guess one could leave the fitting (not QDC) a bit loose and run truck to leak, shut it down and tighten... Too much work and messy.

The tee and brake bleeder valve fitting off the Cadillac valve might / could assist in getting some air out. Here's a link >> See the pictures for the MOD.

Operative word here is MAY... YR MAY V. Click and read on >

Substitution: Fan Hydraulic System Bleeder – HMMWV Systems

Bolt it up & rocket ON , CAMO
[/QUOTE

Well, I read on here after all the work of changing a clutch out... it had a leak.
For me, (and I test everything) better on the bench to discover the problem than in the truck IMO.

Again I don't think it matters fluid or air. Any ATF fluid from the Cadillac valve is going to compress the air in the line / clutch to the pressure needed to work releasing the clutch.

Maybe over time some air might seep past the clutch seals or QDC, that's a big maybe and would hope not LOL.

Just not sure how to get a complete purge end to end and never worried about it. Guess one could leave the fitting (not QDC) a bit loose and run truck to leak, shut it down and tighten... Too much work and messy.

The tee and brake bleeder valve fitting off the Cadillac valve might / could assist in getting some air out. Here's a link >> See the pictures for the MOD.

Operative word here is MAY... YR MAY V. Click and read on >

Substitution: Fan Hydraulic System Bleeder – HMMWV Systems

Bolt it up & rocket ON , CAMO

Is it your understanding that the lines to the fan clutch are NOT prefilled with fluid prior to installation? Is normal operation to hook up the lines to the clutch, then fluid from the Cadillac valve compresses the air and operates the fan clutch.... Instead if actually displacing the air with fluid.

 

[Milcommoguy]

I don't understand anything... it just works. Never gave it a second though. Put it together and drive it.

How about you tell me how your going to get fluid all the way to the end of the clutch piston area without some air.

Sent you a link to some fancy bleeder valve set up. Give it a try if you can't sleep at night.

To much info is dangerous, CAMO

 

[fpchief]

Not to test it.... More about the final install. Filling it with fluid before hooking everything up.

Sometimes we would augment the maintenance guys when we HAD to get vehicles back operational. The lines are 100% not prefilled (however you would do that) prior to Install.

 

[Thumper580]

Sometimes we would augment the maintenance guys when we HAD to get vehicles back operational. The lines are 100% not prefilled (however you would do that) prior to Install.

So if I prefill the lines I'm ok....