Dust in cab

When was the last time you replaced the cabin filter?

 

I would think a clogged filter would prevent dust, and air, from entering.
Perhaps a missing filter?

 

how's dust getting into the air duct?

 

Dust is always a problem in a truck. If you have one of those air hoses in your truck that connects to the seat air supply do this. Wait until the sun is out so you can see what happens. Get on the highway and put both windows down and start spraying air everywhere even into the back bunk. Floor, dash...everything.

You don't believe how much dirt and dust will get sucked out the windows.

 

Paccar doesn't (or didn't) install cab filters for the HVAC system. You gotta buy an aftermarket filter kit.

 

cab dust : I'll sweep out the cab before using air while parked, after I get as much as I can, I use soap and water, a couple of different size brushes and paper towels with a little elbow grease. some times I'll apply a slippery slick shine to some of the surface.

seats dash and the immediate visible floor get air often

 

sure would be nice if the air line was longer, cant reach everything, a small decent portable 12v vacuum would be nice too

 

dust collection