Loosening Screws and Lifter Noise

[Mohammed Bhatti <Mohammed.Bhatti@mci.com>]

Ok, so I finally was able to identify and locate the aux vacuum
pump after help from list members.  After struggling for about
40 minutes to loosen the two bolts, the pump finally came off.

Now the problem is, I can't seem to loosen any of 6 screws so
that I can get to insides of the pump.  I've tried DW40 spray
to try and loosen them, but they wont budge.  Some of the screw
heads seem a little "mashed" though.  Do I need some sort of power
tool to loosen the suckers?

I'm trying to figure out if I've got noisy lifters or a bad vacuum
pump.  If I'm driving down the highway and suddunley hear clacking
similar to lifter noise which goes away after about 10-20 seconds,
could this be a bad aux. vac. pump.  Would'nt noisy lifters always
be noisy (other than at startup)?  The clacking noise I hear is 
intermittent and only sometimes heard when driving.  More often
heard while at idle.

Thanks for any info.

mkb
88 80q