Graco 965129, 965124 Displacement Pump Repair, Disassembly, Reassembly, Before you start, Service

Service

Displacement Pump Repair

WARNING

To reduce the risk of serious injury whenever you are instructed to relieve pressure, always follow the Pressure Relief Procedure on page 7.

Before you start:

DTo reduce down time, be sure you have all necessary repair parts available.

DRepair Kit 237498 is available. If you have a repair kit, use all the new parts for the best results. Parts included in the kit are marked with an asterisk (*).

DWhen cleaning parts, use a compatible solvent. Inspect parts for wear or damage and replace as necessary. Scoring or irregular surfaces on the priming rod (8) or polished inner wall of the riser tube (2) causes premature packing wear and leaking. Check these parts by rubbing a finger on the surface and by holding the parts up to the light at a slight angle.

Use light, waterproof grease wherever grease is mentioned.

Disassembly

1.Follow the Pressure Relief Procedure on page 7.

2.Remove nut (10) and priming plate (9) from priming rod (8).

3.Unscrew the foot valve housing (7) from cylinder

(2).

NOTE: Poppet check (6) foot valve packings and bearings (5) slide off priming rod (8) when removing foot valve housing.

4.Unscrew bearing (5) from foot valve (7).

5.Remove the poppet check (6) and inspect foot valve packings (30).

6.Unscrew riser tube (2) from pump base. Clean the tube and inspect it for wear by holding it up to a light at a slight angle. If you see wavy lines or scratches where the piston travels, replace the tube as it will not seal well with the new piston packings and the pump will perform poorly.

7.Loosen the lock nut (4) and unscrew the valve housing (14) from the connecting rod (3), unscrew valve housing (14) from piston housing (16).

8.Remove washers (35*), spreaders (34*), cup packings (36*), o–ring (33*), and cup spacer (20) from the piston housing (16).

9.Clean and inspect all the parts.

Reassembly

1.Reassemble the piston, using all the new parts from the kit and any other new parts needed. Oil the leather cup packings (36*) first. Then assemble the parts on the piston housing (16) in this order: backup washer (35*), spreader (34*), leather packing (36*), cup spacer (20) with new o–ring (33*) installed in it, another leather packing (36*), spreader (34*), and backup washer (35*).

NOTE: To replace the throat packings, follow the procedure given in your separate air motor manual (306982) before continuing with the procedure.

2.Screw the piston assembly onto the connecting rod (3) and adjust the ball travel as instructed in Check Valve Adjustment on page 12. Tighten the locknut (4).

3.Check the o–ring (13) in the pump base and replace it, if necessary.

4.Lubricate the piston packings and the inner wall at the top of the riser tube (2). Wrap the packings with with a guide collar made of 1/64 in. maximum thickness shim stock or metal sheeting. Using a turning motion, work the first leather packing into the riser tube. Remove the guide collar and push the riser tube up and screw it into the base. Torque the tube to 100–150 ft.–lb. (135–204 N–m).

5.Slide bearing (5) onto priming rod (8) with the step side facing the bottom of the pump.

6.Insert foot valve packings (30) into poppet check

(6) replace if necessary.

7.Slide poppet check containing foot valve packings onto priming rod (8) with beveled edge facing the bottom of the pump.

8.Slide foot valve over poppet check and screw bearing (5) into the foot valve (7).

9.Push foot valve up to the riser tube.

10.Inspect o–ring (11) for damage and replace if necessary.

11.Screw foot valve (7) onto riser tube (2).

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