I have a '95 Diesel 77 series. I replaced the automatic hubs with manual hubs a year ago. When I press the 4x4 engage button nothing happens, even the light does not come on. The diff locks also won't engage. If I pull off one of the vacuum lines off the vacuum pump and re-attach it then it engages. What is the possible problem? Is it electrical or the vacuum system? If it is the vacuum pump where can I get another one? What is the best way to trouble shoot this?
4x4 Won't engage
- Thread starter Geobaerg
- Start date
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Try the connections on your 4wd vacuum switching valve. If that is not clicking when you push the button then check for voltage on those wires. There may be a disconnect for the front hubs but I don't think so.