vacuum pump clacker

["PAT MARTIN" <MARDKINS@msn.com>]

For several months my vacuum pump has been clicking so today I decided to take 
it apart and see how it ticks literally.   

When I opened it up it seems to be a simple piston with a return spring with 
several pressure valves of some sort.   It appears that everything was working 
OK but I suspected that maybe at the extended position that there might be 
some slop so I "adjusted the travel out so that it would extend farther and 
not rattle.  I cleaned out the chamber and the spring area but it was not 
really that dirty anyway.  The one thing that concerned me was that on the 
vacuum side there was oil which leads me to believe that the scraper ring on 
the piston is worn.  That could also cause the piston to stick which would 
cause a clacking.   After all of this I started it only to hear it louder and 
more consistent.  Could my adjustment have made it worse and would it help to 
actually put more tension on the spring.  To me it almost sounds like the 
sound is coming from under the valve cover though.

The question is what could be clacking? And if there is a problem with the 
pump does someone have one they could loan me to troubleshoot.  I pay shipping 
and cost if its for sale and I do need it.
BTW: It has new lifters and thanks Pete for the help and the place.
Pat Martin
864000csq 2 1/2 cat back, H&R-Boge,advanced and loving it.  Drilled and 
stopping it.  Koenig Cobra 16x7 with AVS Intermediates, K&N.
95 subaru legacy 
Bothell, Wa.