4x4 Posi Lock and Troubleshooting vacuum leak

[Mschuman88]

Hi All,

This weekend I installed a 4x4 posi-lock system in my '02. I have a couple of questions:

1. The knob seems to thread in and out - is this normal for that setup?
2. I thought the system would fix my vacuum system (heater vent changing) but I still have a leak somewhere. Any tips or procedures on troubleshooting?

I did plug the 4x4 vacuum supply in the engine bay so I don't believe that's the source of my issue.

 

[DonFitzwater]

Hi All,

This weekend I installed a 4x4 posi-lock system in my '02. I have a couple of questions:

1. The knob seems to thread in and out - is this normal for that setup?
2. I thought the system would fix my vacuum system (heater vent changing) but I still have a leak somewhere. Any tips or procedures on troubleshooting?

I did plug the 4x4 vacuum supply in the engine bay so I don't believe that's the source of my issue.

I've found its easiest to get a smoke machine to find vacuum leaks on vehicles. You'll know right away where it's coming from unless it's a leak in the dash. Check carefully around the firewall where the lines go through.

I don't have anything to add on the posi lock other than on my trucks I install the fixed shift fork and forget about it. No moving parts any more!

 

[JR]

Is your hvac stuck on defrost? If so check to make sure the plastic tee up by the firewall isn't cracked. They get brittle and are a known failure point as they age.
Aside from that it's a matter of starting at the vac pump and working your way up. I just went through this on the wifes TDI, and they have ALOT more vacuum lines under the hood I ended up replacing them all as they looked suspect.