2nd Gen Non-Engine/Transmission 4WD Actuator…

[KPotter44]

So I went up in the forest the other day and the 4WD does not work. I think I could hear it trying, but would not fully engage and the light did not come on. I’ve been reading about this and wondering, can I just hook up a hand operated vacuum pump to the actuator and see if it holds vacuum? That would indicate wether or not the diaphragm is still intact, correct? Thanks. Replacing the actuator doesn’t look like a big deal, just want to make sure before I buy parts.

 

[Road Dog]

First, check the vacuum lines for leaks. On my previous truck the tubing touched the exhaust and melted.

Second, check that you have vacuum.

 

[petersonj]

can I just hook up a hand operated vacuum pump to the actuator and see if it holds vacuum?

Yes.

Place the transfer case into 4 HI. Jack up the right wheel. Turn the ignition switch to the "Run" position. Operate your vacuum pump on one of the ports on the CAD unit. The 4wd indicator lamp should light and the right wheel should lock (you may have to rotate the wheel slightly). If one port doesn't work, try the other. These steps will prove whether or not the CAD unit is working properly.

Likely, you have vacuum leaks.

- John

 

[KPotter44]

Thanks Road Dog and John for the comebacks. I purchased a vacuum pump and disconnected the lines at the actuator. Neither side would hold vacuum so I replaced the actuator. Works better than it has for a while. Must have had a pinhole in the diaphragm? Anyway, thanks you guys and I’m back on the road.

 

[petersonj]

Good Job!

- John

 

[Regcabguy]

Maybe the makers will return to a lever. When I ordered mine the fleet guy was curious why I didn't want a knob?

 

[JMcCoy]

Posi-Loc cable actuator will fix your problem for good and give you the option of 4WL. It worked flawlessly for years, until I went to 35 spline solid axle shafts.

 

[Rosie the rustbucket]

Posi-Loc cable actuator will fix your problem for good and give you the option of 4WL. It worked flawlessly for years, until I went to 35 spline solid axle shafts.

What do you mean by 4WL as an option?

 

[BigPapa]

I THINK he meant 2WL. Basically, low range in two-wheel-drive.

 

[JMcCoy]

Yes, 2WL!
Sorry. Lack of sleep!