Pressure Control Replacement - Graco ULTRA 500 Instructions-Parts List Manual

Pressure Control Replacement

WARNING
FLUID INJECTION HAZARD
To reduce the risk of serious injury,
follow the illustrated Pressure Relief
Procedure warning on page 12 when-
ever you are instructed to relieve pressure.
1. Relieve pressure.
2. Disconnect the filter/drain valve assembly and the
pump supply hose at the pressure control while
holding the pressure control fitting (A) firmly. See
the CAUTION, below. See Fig. 17.
CAUTION
Do not allow the fittings (A) to turn when removing
or connecting the hose and filter/drain assembly.
Do not over tighten the screws when attaching the
pressure control board/cover. Turning the fittings or
over tightening the screws may shift the calibration
of the pressure control.
TO GUN
Fig. 17
3. Remove the four mounting screws and washers
(302, 303, 304) from the pressure control board/
cover (301). See Fig. 18.
4. Carefully remove the pressure control board/cover
(301) so as not to stress the cables.
5. Remove the potentiometer cable (310) from the
pressure control board/cover (301).
6. Disconnect the pressure control board/cover black/
white M+ and black M– leads from the motor +
and– leads.
7. Disconnect the red motor leads from the TS leads
on the pressure control board/cover (301).
8. Disconnect the brown power lead (L1) from the
filter board.
9. Disconnect the blue lead (L2) from the filter board.
10. Loosen the ground terminal screw (317) and dis-
connect the ground lead (C).
11. Pull off the pressure control board/cover.
TO PUMP
301
A
FILTER/DRAIN
VALVE ASSEMBLY
A