going from 4 hi to 2hi front axle stays engaged replaced the vacuum solenoid valve but no change

 

3 or 4 button switch on the dash?
Is it equipped with a 3 port vacuum switch on the transfer case, driver side, inboard and above the encoder motor?

 

4 button

 

Check post #2 again.

 

no vacuum switch

 

With the engine at idle, select 2WD: is there manifold vacuum to one of the vacuum lines on the switch that you replaced, (on the firewall)?

 

yes, when i select 4 hi it pulls in the vacuum diaphragm under the batt. box but when i go back to 2hi the diaphragm stays pulled in untill i release the vacuum line that attaches to it

 

Unplug the 2 vacuum lines from the vacuum switch, engine at idle, select 2WD: One port on the switch should hold vacuum when you suck on it The other port should be vented to atmosphere.

The port that holds vacuum must have the engine vacuum line connected to it. The line that goes to the other port goes to the actuator under the battery tray.

This will tell if the lines got transposed, (switched around).

 

that worked thanks captain !

 

Good job! Thanks for posting back.