i have a 2001.5 they are the same as the older trucks 94-2001.5
make sure that the air line that goes from your tcase to your frame up to your right wheeel well is not rusted out.... when i pulled my tranny to put in a clutch i forgot to put it back on but then my 4x4 would not work.. so then after that i found the problem got it together and still did not work. wel the weak i drove around withthe steel tubing not fastend to the frame the rust gave way witch lead to a leak. i fixed that 4x4 worked again two or maybe three weaks later it stoped again and thats where i found the beroken hose by the master cylender.

 

when your metal hose rusted out were did you have to go to get a new one?

 

i have an 02 and under my vp44 there is a fitting that blows off for whatever reason and it shuts off heat and the 4x4 system