what does the front axle vacuum pump on a jeep yj do and what happens if diconnected?

[adgethechamp]

have a 93 jeep yj but i looked under it today the vacuum pump on the front axle is disconnected and was wondering whats the importance of it? thanks

 

[Unregistered]

Hi,

Just saw you post when looking for other info about the vacuum pump. The vacuum pump is responsible for engaging the front wheel drive of the jeep. If the cables are disconnected you do not have 4x4 on your jeep.