Vac readings on a D30 w/disconnect

I will start this question with some info
88 chief
4.0L
5spd with BA 10/5
NP 231 AAC transfer
D30 axles

No 4wd so I got out the vac guage today to check things out. First I put the transfer case in 4Hi, backed up pulled forward and then chocked the rear wheels... jacked up the front passenger side, turned the front drive shaft... no turn, grabbed the passenger wheel, turned fully. Hooked up the vac guage between the vac lines and the vac motor... I got a reading of 18 in.Hg Vac on all three hoses... I assume the motor is not working? is there any other way to check it... I will try to pull it off the axle tomorrow, I also want to check the fork... but any advise is good... am I getting enough vac to work the motor?
thanks for the help

Kyle

I don't want to hijack this thread, but in addition to his problem ^^^^, I seem to have a fluid leak where my motor attaches to the axle. Is there some sort of gasket or something?