when i reach up at the tri vaccum on the t case it seems to be loose or at least i can move it. i tried the vise grip test on the actuator under the battery and the 4x4 works perfect but when i let the vaccum handle it the blazer seems to slip in and out of 4 wheel drive when iaccellerate, do you have to take the t case down to replace or repair this fitting??????????

 

It's not a fitting, it's a switch. No, you do not have to take the T-case out to change it, just get a 7/8" wrench and spin it out. It sounds more to me like you have a rotted vacuum hose though.

 

Well, I guess posting in your own thread is better than jumping on someone elses...

As I said in the other thread where you asked this question, I have big hands/forearms and I have never had any issues messing with this fitting.

As Bill pointed out though, if you are messing with the lines, it may make it easier to get to them by removing the transmission cross member and dropping the back of transmission/transfer-case down.

You can test for a vacuum leak by using an unlit propane torch, tracing around any suspected leak locations with the engine idling. If the idle speed changes, you have found a leak.

 

Excellent idea, I've never heard that one before. I'm going to have to try this out myself.