hello I have a 98 chevy blazer and have a problem with the actuator. There is a constant suction from the vacuum hose that hooks to the actuator and I was wondering if anyone knew why this is. Even when I have it in 2hi the actuator stays engaged from the vacuum suction. so I have to unhook the vacuum hose to release the cable.

 

Go underneath your blazer and on top of the transfer case there is a vacuum transfer switch. More than likely its stuck in the 4wd position. you can replace it with one from Autozone for less than $20.00 That was what was wrong with mine. Its just above the front driveshaft on the drivers side. It has 3 hoses connected to it. This little vacuum switch tells the front axle when to engage.

I had the same problem on my 96.

 

did you have the floor shifter on yours? im having something similar the front axle on mine is locked up and i can physically shift it into 2 wheel drive but the transfer case is still in fourwheel drive.