Service Manuals

What info are you looking for ? I have a 379 man aswell as 357 they share the same cabs

 

I am looking for how to repair an air operated passenger window it stopped working where do I start

 

It's a simple system, any air leaks when you hit the switch? If not, start at the switch. It needs air going in and the 2 small lines are up and down. Take the small lines off the switch and verify that 1 has air when the switch is push up and the other has air when pushing down. If that checks out, you need to pull the door panel and to that same check at the lift cylinder t verify that the lines are not kinked of plugged. If you are getting air up and down at the lift cylinder, the the cylinder is probably bad, but first disconnect the window from it and manually operate it to make sure it's not stuck.