3M Graco 50261 Manuel D'instructions page 11

Replacing the air and fluid packings
with gun rebuild kit 50275
Tools needed:
• Wrench 8 mm (5/16 in.)
• Wrench 19 mm (3/4 in.)
• Gun Tool (28) supplied with gun
• Packing Installation Tool (29) supplied with gun
• Mechanics O-ring pick
• Needle nose pliers
• Gun Lube Part No. 50281
WARNING
PRESSURIZED EQUIPMENT HAZARD
To reduce the risk of a serious injury, follow the Pressure Relief
Procedure on page 6 whenever you
NOTE:
• Gun Repair Kit 50275 comes complete with all air and fluid seals
required to rebuild the spray gun.
• Clean parts with a solvent that is compatible with the parts and
the fluid being sprayed.
• Lightly lubricate the parts indicated in Fig. 21 with lubricant 50281.
This item is not included with gun.
Disassembling the gun
1. Relieve the pressure.
2. Flush the spray gun, page 3.
3. Remove the air cap retaining ring (15) and air cap (14).
Remove and replace the seal (15B). See Fig. 22.
12
Fig. 22
4. Trigger the gun while you remove the fluid nozzle (12) with the
gun tool (28).
CAUTION
Trigger the gun whenever you tighten or remove the nozzle. This
keeps the needle seat away from the nozzle seating surface and
prevents the seat from being damaged.
5. Remove the fluid adjustment knob (21) and fluid spring (23).
See Fig. 21, page 10.
6. Pull the fluid needle (13) out the back of the gun.
7. Remove the screw (11), pin (17), wave washer (18), and trigger (10).
8. Remove the hex nut (9) with the gun tool (28).
9. Remove the spray housing (2a) and adapter (4).
Service
are instructed to relieve pressure.
2
1
1 1
Replacing the spray housing o-rings
and packings
1
1
1
2 2a
Fig. 23
1. With the spray housing (2a) removed from the adapter (4), use a
mechanical pick to remove the o-ring (2b) from the housing (2a).
2. Remove o-ring (34) from the adapter (4). See Fig. 23.
NOTE: O-ring (2b) is slightly
3. Install a new o-ring (34) into the adapter (4). Install a new o-ring
(2b) into the housing (2a).
NOTE: To ease o-ring installation, place the adapter (4) into the
spray housing (2a) to plug the end. Install one end of the o-ring
into the groove in the housing, then press the rest of the o-ring
into place.
4. Unscrew the packing screw (8) from the adapter (4) with the
gun tool (28).
5. Using a mechanical pick, push the three fluid packings (5) out of
the adapter (4). Be careful not to damage the adapter. Discard the
old fluid packings.
6. Place the new fluid packings (5) and packing screw (8) onto the
needle (13). See Fig. 24 for the orientation of the parts.
Fig. 24
7. Insert the fluid needle (13) into the back of the adapter (4) to
install the fluid packings (5).
8. Tighten the packing screw (8) just enough to hold the packings (5)
in the adapter (4). The needle (13) must move freely.
Remove the needle.
11
12
1
11
1
1
9
10
larger than o-ring (34).