Disassemble The Displacement Pump - Graco Dura-Flo 1200 Instructions Manual

Maintenance
Disassemble the Displacement
Pump
When disassembling the pump, lay out all the removed
parts in sequence, to ease reassembly.
NOTE: Packing Repair Kits are available. For the best
results, use all the new parts in the kit. Kit parts are
marked with *. You can also convert the pump to
different packing materials. See Packing Kits, page 21.
1. Place the pump lengthwise in a large vise, with the
jaws on the outlet housing (7) as shown in F
page 15. Using the supplied wrench (110), loosen,
but do not remove, the packing nut (2).
2. Apply a pipe wrench to the flats of the intake valve
(19) from the intake housing (18). Be careful to
catch the intake ball (17) as you remove the intake
valve, so that it does not fall and suffer damage.
Remove the seal (8) from the intake valve. Inspect
the ball and the seat (BS) of the intake valve for
wear or damage.
3. Apply a pipe wrench to the hex of the valve housing
(18). The pump assembly may separate at joint A or
joint B.
To reduced the possibility of damage to the rod (1)
and cylinder (9), always use a rubber mallet to drive
the rod out of the cylinder. Never use a hammer to
drive out the rod,
• If the assembly separates at joint A:
a. Unscrew the valve housing (18) from the
cylinder.
b. Using a rubber mallet, drive the displacement
rod (1) and piston assembly out of the outlet
housing (7) and cylinder (9) until the piston
comes free. Pull the rod and piston from the
cylinder, being careful not to scratch the parts.
c. Unscrew the cylinder (9) from the outlet housing
(7), using a pipe wrench.
d. Remove the two seals (8) from the cylinder.
Shine a light into the cylinder (9) to inspect the
inner surface for scoring or wear.
e. Proceed to step 6.
14
NOTICE
• If the assembly separates at joint B:
a. Unscrew the cylinder (9) and valve housing (18)
from the outlet housing (7).
b. Gently pull the cylinder and valve housing
straight out of the outlet housing; the
displacement rod (1) and piston assembly will
come out with these parts.
c. Place the valve housing (18) in the vise and
unscrew the cylinder (9) from the housing, using
a pipe wrench. The displacement rod (1) and
. 3,
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piston assembly will remain in the cylinder.
d. Using a rubber mallet, drive the displacement
rod (1) and piston assembly out of the cylinder
(9) until the piston comes free. Pull the rod and
piston from the cylinder, being careful not to
scratch the parts.
e. Remove the two seals (8) from the cylinder.
Shine a light into the cylinder (9) to inspect the
inner surface for scoring or wear.
f. Proceed to step 6.
4. Place the flats of the piston seat housing (16) in a
vise, as shown in F
5. Using an adjustable wrench, unscrew the piston ball
housing (10) from the piston seat housing. Be
careful to catch the piston ball (11) as you separate
the piston seat housing and ball housing, so that it
does not fall and suffer damage.
6. Examine the displacement rod (1) for scratches or
other damage. Only if the rod needs replacement,
unscrew it from the piston ball housing (10), using
an adjustable wrench on the flats of the rod.
7. Remove the glands and v-packings (PV) from the
piston seat housing (16). Inspect the ball (11), and
the seat (PS) and guides (PG) on the housing for
wear or damage. See F
8. Unscrew the packing nut (2) from the outlet housing
(7). Remove the glands and v-packings (OV). See
F . 5, page 18.
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9. Clean all parts with a compatible solvent and
inspect them for wear or damage.
. 4, page 15.
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. 5, page 18.
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