Craftsman 580.988390 Operator's Manual page 9

LubricateO-Rings
Lubrication of o-rings is extremely important for installation
and operation. The use of a lubricant (petroleum or synthetic
grease) during assembly helps seat o-rings properly and
provides an improved seal. It also helps protect the o-ring
from damage by abrasion, pinching or cutting and extends
the life of the o-ring.
NOTICE ALWAYSapply a small amount of lubricant on
o-rings prior to assembling the garden hose to the pump
(A), high pressure hose (pump end) (B), high pressure hose
(gun end) (C), turbo wand (gun end) (D), adjustable fan
jet wand (fan jet end) (E) and adjustable fan jet wand (gun
end) (F).
Lubricate all connectionsshown below, following these
instructions:
1. inspect and clean connecting surfaces prior to lubrication
and assembly.
2. Use lubricants sparingly during assembly; a light film is
all that is required.
3. Use a small brush or cotton swab to apply grease directly
to o-rings where they are not accessible (QCfitting, M22
fitting).