[House]

just got the tow rig back from a motor swap, they pulled the cab to do it, at first the air conditioning was working right when picked up, but now its coming out the defrost vents, any idea's?

 

[gregrob]

Vacum leak somewhere, it defaults to that position. Poke around inside the pass side fender where the pump and reservoir, check all the lines, and the res for cracks.

 

[THEDIESELMAN]

Yep you have a vacum leak somewhere but I would check out the lines going to the hubs.

 

[fishinfool98]

check the lines in the pass floor board also mine was doing the same thing
a while back just look for a tee thats where mine was LOOSE

 

[Sapps]

Who did the swap? What was wrong with the old one? What mods to the new motor?

 

[Cool Canuck]

You might want to start at the vacuum pump and make sure it is working first. (Passenger Fender) and the go from there.

 

[Arisley]

Yep, it may have been damaged in the cab removal.

 

[skylinedan]

Yup those lines have a tendicy to get hard from age and heat under the hood so they get brittle and when you go messing with them they brake real easy. Or some one just missed the line when they put the cab back on, I've done it. I goe throught the truck and make sure everything works right before the customer picks it back up, but you get in a hurry and things get missed.

Dan

 

[Arisley]

Usually little things.