4x4 problems w/ 96 s-10 blazer

Hello all,

I am pulling my hair out with this one. My wifes 1996 4.3L S-10 blazer kicks out of 4x4 hi when you accellerate hard or reach about 45-50 mph. I don't mean stomping on it either, for example, driveing down road at 40 mph in 4 hi, accelerate to go around someone and 4x4 disengages. This problem started after the 4wd vaccume switch on transfer case was replaced.

Blazer has manual 4wd shifter on floor. I have re-replaced vac switch on transfer case, I have vac at diaphragm under battery and it engages front axle fine, the diaphragm is new also. I have looked at vac lines from what I can see and they appear to be intact. I have had it back to dealership 3 times for same problem, they always say it is fixed and here I am again.

Any ideas? I could use the help!

Check and replace all vacuum lines if they are at all defective or cracked.

This sounds like a vacuum bleed off.

thanks for the input Blazer!!! I appreciate you help. I was thinking that should be the next step. I know that I have one vac line supplying the transfer case and then two running up the fire wall. One goes to vent and the other to the diaphragm. Unless I am missing something else, I will check those let every one know.

thanks again...

Check the connection going to the vacuum ball.

I know my hose there is in bad shape and once I had some idling problems and low and behold, the hose was almost off the ball connection nipple.

Hehe, hey beavis, I said nipple...

Hehe..... YA! ....YA!

Thanks again blazer! I will let you know how it turns out. Once again I appreciate your help.

No prob.