have a 85 s10 blazer 4x4 have replaced the vacuum switch and the vacuum actuator still nothing could there be a vacuum line that is leaking when i engage the 4 wheel drive the shift cable that connects to the acuator dont move at all and if its a vacuum line or lines does anyone know off hand what sizes they are the 3 that come off the vacuum switch go to actuator and to the manifold im not sure were the other one goes i havent looked any help would be apperciated

 

They are likely 1/8" or 3/16" vacuum lines. A quick measurement would tell you. There will be one line that runs from the engine to the vacuum switch. Another line that runs from the vacuum switch to the actuator. The third line is just a vent to release the actuator once the transfer case shifts out of either of the two 4wd modes.

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