Troubleshooting Chart - Graco Hydra-Cat H.P. Series Instructions Manual

PROBLEM
System will not run or
stops while running.
The fluid pressure
bounces significantly
(>500 psi) while pump is
running
Mix ratio test is
significantly different from
the mix ratio setting.
Spray output is spitting
A squeaking or knocking
noise is heard.
The proportioner speeds
up or runs erratically

Troubleshooting Chart

CAUSE SOLUTION
Air pressure or air Increase air pressure. Check air compressor and air supply filters
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
Air volume is too Verify that air pressure at the air motor inlet is not dropping during
low. pump changeover. Check air compressor and air supply filters
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. 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 was Perform ratio test again following ratio test procedure on page 12.
not performed at
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.
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.
The bearings are Lubricate the bearings or replace them if required. See "service the
dry or worn. bearings" on page 18.
Running out of one Check and refill material reservoirs.
material.
The cylinders are See troubleshooting techniques below to isolate the problem
worn or damaged. cylinder(s). See "Service the cylinders" on page 16.
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