vacuum disconnect axle locking system

[buckeyes8603]

I have a 95 ex with a 4x4 prob. when i switch from 2wd to 4wd the light goes on in the cab but no 4wd i read some on this vacuum disconnect axle locking system but have know idea how to troubleshoot to find out what is really going so if anyone can direct me to some literature on the system and how to troubleshoot it that would be great. someone also said that it was an o-ring is this true or not I don't just want to start throwing things at it hoping that it resolves the problem. so if anyone know anything about this system please help

 

[Cobraguy]

You have two vacuum lines down to the right side axle and they plug into a vacuum motor. Vacuum on one port engages the axle halves and gives you 4WD. Vacuum on the other port disconnects the axle for 2WD. You more than likely have a bad vacuum line, reservoir, leak, etc. But it's possible to be a bad motor (bellows) too. Finally, there is a fork and slider in there. But it would surprise me if they are bad. Shoot...just pull the disconnect off the axle and take it to your bench to check. Be careful not to tear the gasket. Four simple screws and it pops off. Apply vacuum to each side and see if it holds vacuum...and moves the slider.