Graco 965477, 965478, 965481, 965479, 965466 Troubleshooting Chart, Problem, Cause, Solution, 684025

Troubleshooting Chart

PROBLEM	CAUSE				SOLUTION
System will not run or	Air	pressure or		air	Increase air pressure. Check air compressor and air supply filters
stops while running.	volume is too low.				regulator, lubricator valves and other components for blockages
					and restrictions. If this is a new system, be sure that air supply
					components have been sized properly.
	The	fluid	valves or		Check the gun, fluid hoses, mix manifold, static mixer, fluid filters,
	hoses are closed or				regulators, valves and other fluid line components for blockages
	restricted.				and restrictions. If this is a new system, be sure that the fluid
					components have been sized properly.
	The	air	motor	is	Service the air motor. See “servicing the Air Motor” on page 17.
	worn or damaged.
	The displacement				See troubleshooting techniques below to isolate the problem
	cylinder(s) is				cylinder. See “Service the cylinders” on page 16.
	damaged or has
	seized
The fluid pressure	Air	volume is		too	Verify that air pressure at the air motor inlet is not dropping during
bounces significantly	low.				pump changeover. Check air compressor and air supply filters
(>500 psi) while pump is					regulator, lubricator valves and other components for blockages and
running					restrictions. If this is a new system, be sure that air supply
					components have been sized properly. 1” NPT hoses, fittings and
					accessories are required to provide the necessary air volume.
	Feed pump				Reduce feed pump pressure. Feed pump pressures must be less
	pressure is too				than 25% of proportioner output pressure.
	high.
	The displacement				See troubleshooting techniques below to isolate the problem
	cylinder(s) check				cylinder. See “Service the cylinders” on page 16.
	valves are not
	seating.
Mix ratio test is	Mix ratio test was				Perform ratio test again following ratio test procedure on page 12.
significantly different from	not performed at
the mix ratio setting.	the normal
	operating pressure
	of the pump
	Running out of one				Check and refill material reservoirs. Repeat the test after the air has
	material.				been removed from the system.
	The displacement				See troubleshooting techniques below to isolate the problem
	cylinder(s) are worn				cylinder(s). See “Service the cylinders” on page 16.
	or the check valves
	are not seating.
Spray output is spitting	Running out of one				Check and refill material reservoirs. Remember that once air is in
	material.				the fluid system it may take a while for all of it to escape..
	Siphon hoses			are	Tighten and seal all siphon fittings on proportioning pump and feed
	leaking in air.				pumps.
A squeaking or knocking	The	bearings		are	Lubricate the bearings or replace them if required. See “service the
noise is heard.	dry or worn.				bearings” on page 18.
The proportioner speeds	Running out of one				Check and refill material reservoirs.
up or runs erratically	material.
	The	cylinders		are	See troubleshooting techniques below to isolate the problem
	worn or damaged.				cylinder(s). See “Service the cylinders” on page 16.

684025 15