95 4wd not working

[billyb22]

Ok, sorry guys for another 4x4 question. I have read the other threads and found them helpful, but I am still looking for some advice.
My 1995 will not go into 4 wheel drive. When the dash mounted buttons are pressed, the lights come on and the vehicle "moves" like it is in 4x4 mode.
I mean the truck feels like it is geared into 4x4 mode, but the front wheels wont pull. With all the snow and ice here, it is easy to see that the rear wheels are the only ones getting power. The dash lights do not blink. They stay on solid like they are supposed to. This is the same if either HI or LOW is pressed. I had my 7 year old push the buttons while I was under the truck, and I can hear and feel the encoder working. I called the tranny shop and they agreed that the vacuum switch mounted on top of the xfer case should be replaced as it is generally the culprit.
I replaced that today (had a heck of a time getting it restarted in the threads). Still the same problem. My next move is to replace the actuator under the battery. Do you guys agree with this? I have looked at what I can see of the vacuum hoses, and they actually look reaaly good - nice and flexible. I have not taken the battery out yet, but plan to pick up the new part tonight ($51.99 at NAPA) Is ther any way to get it into 4x4 mode and leave it in for now?
Thanks guys for reading through yet another 4x4 question.

[laxman21]

Originally Posted by billyb22

Ok, sorry guys for another 4x4 question. I have read the other threads and found them helpful, but I am still looking for some advice.
My 1995 will not go into 4 wheel drive. When the dash mounted buttons are pressed, the lights come on and the vehicle "moves" like it is in 4x4 mode.
I mean the truck feels like it is geared into 4x4 mode, but the front wheels wont pull. With all the snow and ice here, it is easy to see that the rear wheels are the only ones getting power. The dash lights do not blink. They stay on solid like they are supposed to. This is the same if either HI or LOW is pressed. I had my 7 year old push the buttons while I was under the truck, and I can hear and feel the encoder working. I called the tranny shop and they agreed that the vacuum switch mounted on top of the xfer case should be replaced as it is generally the culprit.
I replaced that today (had a heck of a time getting it restarted in the threads). Still the same problem. My next move is to replace the actuator under the battery. Do you guys agree with this? I have looked at what I can see of the vacuum hoses, and they actually look reaaly good - nice and flexible. I have not taken the battery out yet, but plan to pick up the new part tonight ($51.99 at NAPA) Is ther any way to get it into 4x4 mode and leave it in for now?
Thanks guys for reading through yet another 4x4 question.

How are the vacuum lines? Any holes or rot?

Pull the hose off the actuator and make sure you are getting vacuum to the actuator before replacing it. start truck and put in 4x4.

Before replacing parts, check backward from the actuator next time.

you can check the actuator by pushing it in and placing you finger over the hose hole and see if it holds or just hook up the line and see if it works.

And, yes, it's a pain to get the switch back in.

[billyb22]

I replaced the switch first at the recommendation of a reputable transmission shop owner.
The lines looked nice and supple - I checked those before replcing the switch.
I picked up the new actuator just in case...
I pulled out the battery and tray. Iunbolted the actuator from the fender and as I'm lifting it out, my fingers went right through the rubber diaphram side.
It was as if some solvent or brake fluid rotted and weakend it.
I put in the new actuator and now it works great.
New problem - BRAKE light on dash is lit always - only goes out when brake pedal is pressed.
I will post another thread for that.
Thanks Laxman...