Pressure Relief Procedure; Troubleshooting Chart - Graco GH 733 HYDRA-SPRAY Instructions-Parts List Manual

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SERVICE
WARNING
Always relieve system pressure whenever you are
Pressure Relief Procedure
done spraying for a while and before installing,
injury from high pressure fluid In the system.
removing or cleaning any parts to avoid possible
A/ways
follow this
procedure:
shut off the unit by
depressing the enginestop button (J-see Fig
6).
trigger the spray gun, engage the trigger safety,
close the fuel 'cock (E-see Fig
6).
and slowly
open the drain valve (78). Leave the drain valve
open until you are ready to use the unit again.
TROUBLESHOOTING CHART
PROBLEM
properly.
The gas engine operates, but the
paint pump doesn't operate.
The displacement pump operates,
but the output
is
low on the
upstroke.
The displacement pump operates
but the o u t w t is low on the
downstroke andlor on both
strokes.
There is excessive leakage around
the hydraulic motor piston rod
Paint leaks into the wet-cup.
There are excessive surges a t the
dispensing valve.
CAUSE
The hydraulic motor has stalled.
The pressure setting is too low.
The displacement pump outlet
filter (if used) is dirty or
clogged.
The tip or tip filter (if used) is
clogged.
The hydraulic fluid is too low.
The hydraulic pump is worn or
damaged.
The hydraulic motor is worn
01
damaged.
The displacement pump rod
is
seized by dried paint.
The piston ball check is not
seating properly.
The piston packings are worn or
damaged.
The piston packings are worn or
damaged.
The intake valve ball check is
not seating properly.
The piston rod or seal is worn
or damaged.
The throat packings are worn or
damaged.
The displacement pump Outlet
filter
(if
used) is dirty or
clogged.
The spray tip is too big or
it
is
worn.
SOLUTION
Consult the engine manual.
See "Starting the Engine" on
page 5.
page 6.
Increase the pressure. See
Clean the filter.
Remove the tip and/or the filter
and clean them.
Shut off the unit and add fluid
immediately: See page 4.
Replace the pump. Refer to page
11.
Service the motor. See manual
Service the pump. See page 10,
307-158.
Service the piston ball check.
See page 10.
Replace the packings. See
page 10.
~~
Replace the packings. See
page 10.
~~ ~
Service the intake valve ball
check. See page 10.
Replace these parts. See manual
~~
307-158.
Replace the packings. See
page 10.
Clean the filter.
Change or replace the tip.
8
307-465