Gday mate.... :)Originally Posted by 5D4E48515D523C0 link=1307593822/0#0 date=1307593822
Most likely theres some precipitated mineralisation on and around the valve seat that has captured the ball-bearing and locked the spring as well.
Theyre not difficult to clean out, you just have to be careful of the Spring and the Ball (or other sealing valve arrangement), just in case they do spring out once youve completely removed the adjustment screw.
Once youve removed these parts, the easiest thing to do for removing any calcification, etc is to use those Dentist Pick Tools you see in Jaycar and elsewhere, to remove all of the foreign matter. Another handy device is a Bronze Brush, of the type used by shooters for cleaning out rifle barrels; these make short work of anything thats a bit difficult to remove, when placed in a Drill Chuck and operated at a slow-ish speed.
Once its all gone, give it a good flush-out. If the Spring and Ball are damaged, you might be able to source a replacement from a Bearing Service retailer and maybe even the spring as well. They should both be of s/steel too...
Much easier to do all of this if you remove the Pump of course but I dont know how easy or difficult that will be on your machine....
All the best,