Graco 390 Electric Airless Sprayer Important Safety Instructions Manual page 15

Installation
If pump pin works loose, parts could break off due to
force of pumping action. Parts could project through
air and result in serious injury or property damage.
CAUTION
If the pump jam nut loosens during operation, the
threads of the drive housing will be damaged.
1. Extend pump piston rod full. Apply grease to top of
pump rod at (D) or inside connecting rod (7). Install
jam nut (11) on pump threads.
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2. Install pump rod (D) into connecting rod (7).
3. Install pump pin (32). Verify retainer spring (C) is in
groove over pump pin.
7
C
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4. Push pump (9) up until pump threads engage.
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7
D
11
32
9
5. Screw in pump until threads are flush with top of
drive housing opening.
6. Align pump outlet (E) to back.
E
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7. Screw jam nut (11) up onto pump until nut stops.
Tighten jam nut by hand, then tap 1/8 to 1/4 turn
with a 20 oz (maximum) hammer to approximately
75 ft-lb (102 N•m).
8. Install suction tube (35) and high pressure hose
(14). Tighten nuts (A) and (B).
.
14
B
A
35
9. Fill packing nut with Graco TSL until fluid flows onto
top of seal. Rotate cover (44). Tighten screws (30).
Displacement Pump Replacement
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11
ti
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b
15