AIRLESSCO MP400 - Manual (Page 20)

Troubleshooting
20 332882A
Troubleshooting
Problem Cause Solution
Unit doesn’t prime Air leak due to loose suction
nut Tighten suction nut.
Air leak due to worn o-rings For Hi-Boy: Replace o-ring (108526) on suc-
tion seat and o-ring (867370) below suction
seat.
For Stand: Replace o-ring (120777) on suc-
tion seat and o-ring (121370) below suction
seat.
Air leak due to hole in suction
hose Replace suction hose.
Stuck or fouled balls Service inlet and outlet valves.
Unit primes but has poor or no
pressure Pressure set too low Turn up pressure.
Filter(s) are clogged Clean or replace gun filter, inlet filter, and/or
manifold filter.
Outlet valve fouled/worn. Service outlet valve.
Prime valve bypassing Clean or replace prime valve (866428).
Packings and/or piston worn Tighten packing nut, repack unit.
Unit does not maintain good
spraying pressure Worn spray tip Replace spray tip.
Packings and/or pistons worn Repack unit.
Upper seat worn Replace upper seat.
Unit does not run Blown fuse Replace fuse:
120V models: 12.5A time delay fuse
220V - 240V models: 8A time delay fuse