Graco ULTRA 500 Instructions-Parts List Manual page 26

PRESSURE CONTROL REPLACEMENT (Refer to Fig 20)
Tools Needed:
Phillips screwdriver
314" open end wrench
112" open end wrench
Adjustable wrench
Small screwdriver
1. Disconnect the main fluid hose
( 9 0 )
and the secon-
2. Disconnect the fluid hose (47) from between the
dary fluid hose, if used, from the sprayer.
displacement pump outlet nipple
(46)
and pressure 47
control inlet nipple (344).
3. Loosen the filter bracket nut (28) and washer (13)
using a 314" open end wrench.
4. Hold the pressure control adapter (3411 firmly with
a 314" open end wrench. Use an adjustable wrench
filter (48).
to loosen the swivel union (8). then remove the fluid
5. Remove the pressure control cover and screws (36,
15). and disconnect the four motor leads st the ap-
propriate terminals.
6. Refer to Circuit Board Replacement on page 25,
remove the circuit board and retain.
7. Remove the conduit (22).
8.
Use a 112" open end wrench
to
loosen and remove
the pressure control mounting screws (37) located
below the pressure control box. Remove the box.
9. Install the new pressure control assembly in the
reverse order of disassembly. Be sure to reinstall
the conduit seal &not shown) around the wires in
ne
the conduit connector (54) to Drevent motor con-
tamination from entering the control box.
10. Perform the pressure control calibration procedure
on page 27, before regular operation of the sprayer.