Repair, Replace air cylinder seals | Graco 313342D instruction

Repair

Reference parts illustration on page 8.

1.Remove dosing valve from sprayer system. See system repair manual for instructions.

2.Mount the valve upside down in a vice holding the upper flats of housing (8).

3.Remove screws (27) and seat housing (26). Remove seat (24), and o-rings (25) from housing

(8).

4.Remove housing (8) from vice and clamp upper flats of air cylinder (2) in vice.

5.Unscrew packing nut (7) and remove locknuts (16). Pull fluid housing (8) straight up off of needle assembly (10) and packing stack (17, 18, 19).

6.Unscrew needle (10) from piston rod (5).

7.Remove packings (17, 18, 19). Inspect needle (10) and replace if worn.

Replace air cylinder seals:

1. Unscrew cylinder (4) from cap (2).

NOTE:

For 255478 only: A phillips screwdriver can be used as a handle in the holes on the flats to unscrew cap (2).

2.Unscrew locknut (11).

3.Remove piston (3) and replace o-rings (12, 13, 14, and 23).

4.Clean all parts and lubricate seals with lithium grease.

5.Reassemble using illustration and notes on page 8 and 9.

6.Use loose o-ring (36) when re-mounting your circu- lation valve to the front of the dosing valve 255478.

313342D