Service
Disassembly
When disassembling the pump, lay out all removed parts in sequence, to ease reassembly. Refer to Fig. 7.
NOTE: Repair Kit 222784 is available separately to replace the piston and intake valve seals. For the best results, use all the new parts in the kit. Kit parts are marked with one asterisk, for example (8*). See Dis- placement Pump Parts on page 23.
Repair Kit 222785 is available to replace the throat packings. For the best results, use all the new parts in the kit. Kit parts are marked with a check mark, for example (3n).
1.Disconnect the displacement pump from the air motor as explained on page 12.
2.Place the pump in a vise, with the jaws on the outlet housing (9).
3.Hold the flats of the priming piston rod (21) with an 8 mm wrench. Using a 3/4 in. wrench, unscrew the priming piston nut (22) from the rod. Slide the priming piston (23) and priming piston guide (24) off the rod. Inspect the surfaces of the guide (24) and piston (23) for scoring, wear, or other damage.
4.Loosen the packing nut (2) using the packing nut wrench (113, supplied), or a hammer and brass rod.
5.Remove the intake cylinder (20), using a 24 in. adjustable wrench. Remove the seal (19) and seat (18) from the intake valve housing (16); always replace the seal with a new one.
6.Unscrew the intake valve housing (16) from the cylinder (11), using a 24 in. adjustable wrench. Pull the housing off the pump. The intake check valve assembly (U) should slide down the priming piston rod (21) as you remove the housing; if it does not slide easily, loosen it by firmly tapping the top of the housing (16) with a rubber mallet. Take care not to drop the assembly (U) as it comes free. Set the check valve assembly aside for disassembly later.
7.Inspect the rod guide (17) while in place in the housing (16). Remove the rod guide only if it is visibly damaged. Using a hammer and brass rod, gently tap around the outer edge of the guide to loosen it.
8.Push the displacement rod (1) down as far as possible, then pull it and the priming piston rod
(21)out of the outlet housing (9) and cylinder (11).
9.Remove the packing nut (2) and throat packings from the outlet housing (9). Do not remove the fluid outlet nipple (7) and
10.Unscrew the plug (AA) of the bleeder valve (33) completely from the valve housing (BB). Do not unscrew the valve housing from the outlet housing (9), because the threads may gall. Clean the valve threads and the bleed hole on the underside of the valve housing.
11.Use a 24 in. adjustable wrench on the pump cylinder (11) flats to unscrew it from the housing
(9).Remove the
12.Inspect the surface of the displacement rod (1) and priming piston rod (21) for wear, scoring or other damage by running a finger over the surface.
13.Use a vise with soft jaws to hold the displacement rod (1) by its flats. Place a 15 mm wrench on the piston flats and unscrew the piston (13) and prim- ing piston rod (21) from the displacement rod (1). Remove the piston guide assembly (V) from the piston (13), and set aside for disassembly later.
14.It is not necessary to remove the priming piston rod (21) from the piston (13) unless you see scor- ing, wear, or other damage to either part. To disassemble, place the piston flats in a vise. Using an 8 mm wrench on the rod flats, unscrew the rod.
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