Posted by chriscase on Monday, October 15, 2007 at 00:51:41 :
In Reply to: The stuff that looks like rabbit droppings? posted by chriscase on Monday, October 15, 2007 at 00:41:20 :
Not on the old PW's, but on modern pumps?
Two ceramic rings, each with one face honed to flat within a couple millions of an inch. So flat that when they mate, water can't flow between them. Then one part has a rubber O-ring inside, that grabs it to the shaft, the other has an o-ring outside that grabs it to the housing. And there is a spring to keep pressure on the two. Wa-la, high pressure, high seal, long life. Used in A/C compressors too, where they leak less than 1/2 oz Freon per year. The o-rings allow a bit of flex for when the bearings get a bit looose. Seal, shaft, and bearings come as one unit for rebuilders. Called a um 'pellet'?, for about $6.
Our old pumps with the zerk use a more normal seal. But can be found in the more modern type from most rebuilders.