Graco 222839 Series A Heat Pump User Manual


 
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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 o-ring (8) unless dam-
aged.
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 o-rings (10). Inspect the inside of
the cylinder for damage by holding it up to the light
at an angle or running a finger over the surface.
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.