front hub question

[RiverSide]

when i engage 4x4 the hubs lock fine,but when i disengage the 4x4 the hubs stay locked.I can not spin the front axle.when i manually turn the hubs to lock and back to auto they free up and i can turn the front axle again.
I,ve read somewhere that it take some time for the hubs to free up but even after several miles and bumps etc...they still are locked.Unless i move them manually on & off once.

p.s took them apart cleaned them and greased the hubs..(twice now)
any tips?

[dhanna6powerstroke]

Ever tried backing up 10 feet?

[RiverSide]

yes did that,..still locked.

[dhanna6powerstroke]

Maybe the switch isn't shutting the vacuum pump off. Not sure.

[RiverSide]

i,ll remove the vacuum tubes after engaging the 4x4 and see what happens.