Nice looking truck Rich, I'm real partial to the 3604's and I hope mine turns out as well as yours when I finally get to the body work.
At full vacuum the pump should be quite strong and you shouldn‘t have to wet down the window to get them going. I agree with Dave, you shouldn’t here a sucking sound when it's running. You may hear it when you turn it on or off though.
As I said earlier, just cleaning and greasing up the paddle does not mean that it will seal in the bore. In fact a lot of people make the mistake of washing the paddle with solvent which actually does more harm than just greasing it, because it washes away what ever the stuff is the treat it with. Unless you had new gaskets the old ones were probably quite dried out and even if you were very careful you may be getting a small leak at one of them.
I've tried for years with no success, to find out just what that paddle is made of. They were some sort of woven fabric that was impregnated with something that looks like a graphite but that's about all I know.
Even when they were new, the vacuum wipers were marginal at high throttle settings. That's exactly why GM offered the dual action fuel/vacuum pumps as an option. And again, Ficken Wiper Service,
http://www.wiperman.com/ will properly rebuild your motor for about a hundred bucks with new parts. I’ve never heard any complaints from anyone that had theirs rebuilt by them. In fact the only reports that I have heard, is that they worked great after getting them back.
DG
