I also love my silca. I just bought new washers for the chuck and a replacement leather washer and a new one of those valves that the OP needed to clean. Total cost was like $8, I only needed the chuck washer, but I wanted enough parts to keep this thing running until I die. The pump is fantastic, I've had it since my blue two barrel Zefal self destructed in the early 80's.
You guy can keep your plastic pumps, I'll keep using this columbus tubing baby until I die.
Sheldon