I was at the local sand drags and noticed when I had it locked in 4 high with the a/c on vent it would every so often blow out the defrost.What is going on...vacuum leak and where?

 

Good Morning Chris, you are right, it is a vacuum leak, normally one of the lines leading down to your hubs. If you have ABS it will be tie wrapped to the abs wire.

 

Mine started doing that this summer. I have WARN manual hubs and I ripped out all of the vacuum lines from the knuckles to the pump years ago..

 

Mine did that a few years back.Replaced the hoses and no go.I had to replace the Pulse Vacuum Hub Solonoid.

 

Mine was the vacuum pump on the passenger fender well and the hoses to the hubs.

 

Mine did it as well. Did my monthly 4x4 engaugement to keep things lubed up and it blew thru the vents. With my truck running I checked the small hoses at the little vac pump to the reservoir, wiggled and pushed them tighter on and heard the defrost go back to the vents. Checked the hose connections behind the glove compartment(Thanks BD), snugged them too. I figured I'd explain for anybody not knowing what to look for.

 

Thank you for taking the time to post this. I'm going to give that a shot.

 

My pleasure Jason. Just passin on great knowledge that I've learned here. Don't you got the manual hubs now?? Can't remember if it was you or somebody else..I know these ESOF systems are a bugger with vacuum leaks but I paid extra for this option and gosh darn it I'm keeping it, god willing, lol..

 

Yep, WARN manuals and I removed ALL the vacuum lines from the knuckles to the pump. I'm going to go disconnect every line remaining and put a little petroleum jelly on each fitting.

 

Very good choice, seems like theres no other really, its Warns or go home, broke. The vasoline technique, To check for leaks from the pump and reservoir just for kicks??

 

Just hoping something is leaking because it is dry rubber/plastic

 

yea my pump took a dump (2a451 i think is the part #) after that problem gone