4wd issues

[albany9044]

so recently ive been having issues with my 4wd so ill start at the beginning. It all started with my actuator going out, so i replaced it and ever since then i still havent been able to get the 4wd to disengage. it will engage and go into 4wd just fine but then when i go to put it back in 2hi im not getting any vacuum out of the solenoid. i tried replacing the solenoid and it worked for 5 minutes then stopped working again. however, i did notice the if i plug the vacuum supply line on the 4wd solenoid (the line that runs from the vacuum resevoir to 4wd solenoid) that the 2wd solenoid disengages the actuator like its supposed to. so im almost wondering if maybe there is a leak in the 4wd solenoid. i have vacuum tested all the lines and they are all fine. any input is greatly appreciated. and i will include the vacuum diagram for reference, thank you.

 

[tonydiv]

I'm assuming that you have a 97 or 98.

I just ditched the entire vacuum system and installed a 4x4posi-lok cable. That way I decide when the front axle is engaged.

If you really want to keep the stock system, make sure that those vac lines aren't full of debris, that could mess up the trigger solenoid.

I would also switch them out to make sure that its the solenoid and not the wiring to the solenoid or the switch.

 

[albany9044]

yes, i have a 98. and i already tried replacing all the vacuum lines and fittings and checked the resevoir

 

[98EXPnSRQ]

This guy does a pretty good job of troubleshooting the 4wd solenoids.

https://www.youtube.com/watch?v=AWXiArMiqBw