Graco 253361 Series C, 246781 Series C Displacement Pump Service, Disassembly, Relieve pressure

Displacement Pump Service

Displacement Pump Service

•Be sure you have all necessary parts on hand before you start. If using a repair kit, use all the parts in the kit for the best results.

•Displacement Pump Repair Kit 246920 is available. Parts included in the kit are marked with a dagger

(†) in the parts drawing and list.

Disassembly

1.Flush pump.

2.Relieve pressure, (page 6).

3.Disconnect hoses and remove pump from its mounting. Clamp the air motor base (5) in a vise.

CAUTION

To avoid damaging the shovel tube, do not use slots in the tube to tighten or loosen tube.

10.Check to make sure there is endplay at pinned con- nections.

When there is endplay at the pinned connection, you should be able to slightly move from

side-to-side, the connecting rod (57) pinned to the displacement rod (8) and the piston (52) pinned to the priming rod (58).

If these connections seem too rigid:

•remove the pin

•adjust hole alignment by 1/2 turn in the direction that aligns the thru holes as close as possible, axis-to-axis (FIG. 3). Improper alignment take the self-aligning feature out of the design, which could result in damage to the pump.

Fig 1 - 1/2 Turn Too Deep	Does not permit
	end play

ti10469a

Incorrect Alignment

4.Use strap wrench to remove shovel tube (67).

5.Unscrew shovel (66) from priming rod (58).

6.Unscrew seal retainer (63) from pump cylinder (59). Remove o-ring (61) from seal retainer. Inspect all parts for damage.

7.Use a strap wrench to remove pump cylinder (59) from the extension tube (64). Remove intake seal (62) from pump cylinder. Remove gasket seal (60) from pump cylinder. Inspect all parts for damage.

8.Use a small punch to drive pin (53) out of connect- ing rod (57) and piston (52) connection. Unless priming rod (58) is damaged, leave the pin connect- ing the piston (52) and priming rod (58) assembled.

9.Unscrew piston/priming rod assembly from the con- necting rod (57). Slide piston seal (54) off piston and inspect for damage.

Fig 2 - 1/2 Turn Too Shallow

ti10479a

Does not permit end play

Fig 3 - Correct Permits end play

ti10468a

Correct Alignment

FIG. 3

11.Clean all parts in a compatible solvent and inspect them for wear or damage.

8 309966H