M939A2 fan clutch actuator OUTLET elbow question

[Alexsha]

So, like many, my fan cutch actuator leaks air. Enough so that when I shut the truck off, it airs down pretty quickly. This leaking also seems to cause the fan to run more than it needs to. And so, today I embarked upon a journey to fix the problem (hopefully).

I drained almost 5 gallons of coolant before I could remove the part in question. I disassembled it and checked the 3 o-rings. They seem fine. I cleaned the whole thing with WD40, dried, and lubed it up with silicone. After reassembly, it leaks just slightly. I'm guessing I'll have to take it apart again soon and replace the o-rings.

When I had the thing apart I noticed something odd about the elbow fitting on the outlet port. It was stuffed with copper wire. This let's barely any air through. I have attached a picture of the elbow. Is this normal?

 

[R Racing]

Yes that is normal , its a bronze filter .

 

[MtnSnow]

Yep...It's the filter

 

[Alexsha]

How much air is supposed to be able to pass through the filter? I pressed an air fitting up to it and tried to pump 60psi through it and barely got anything.

 

[Alexsha]

And 1 more question: should there be no air leaking from the hole in the cap or will there always be some air leaking?

 

[Doug Roberts]

mine has started doing the very same thing. It's blowing hard out the actuator. I was thinking I'd have to replace it.

 

[MtnSnow]

Honestly not sure on the air if there should/would be zero air as mine will bubble soapy water.... But on way to help clean those sintered bronze filters is to soak them in vinegar (or carb cleaner etc) at least over night and then reverse pressure (opposite the normal flow) rinse.

 

[idbankrman]

The bronze filter is very hard to clear. Air should not come out the back of the actuator except when the fan is operating and then only a small amount.