Disassembly - Graco Dura-Flo 1800 Instructions And Parts Manual

Disassembly

Lay out all the removed parts in sequence, to ease reas-
sembly. Clean all parts with a compatible solvent and
inspect them for wear or damage. Refer to F
Repair Kits are available to replace the throat (T)
and piston (P) packings, and to replace the o-rings
and cylinder seals. For the best results, use all the
new parts in the kit. Kit parts are marked with an
asterisk, for example (11*). These kits also can be
used to convert the lower to different packing mate-
rials. Refer to pages 16-20.
1. Flush the pump, if possible. Stop the pump at the
bottom of its stroke. Relieve the pressure, page 6.
2. Disconnect the lower from the motor. See your sep-
arate pump assembly manual.
3. Stand the lower upright in a large vise. Loosen, but
do not remove, the packing nut (3). Remove the six
long cap screws (20).
4. Lift the outlet housing (19) straight up off the lower.
Be careful not to scratch the displacement rod (1)
while removing the housing.
5. Lift the cylinder (7), displacement rod (1), and piston
assembly off the intake housing (17).
6. Remove the seal (6), ball guide (14), intake ball
(16), intake seat housing (15), and o-ring (27) from
the intake housing (17). Inspect the ball (16) and the
ball seat (A) on the housing (15) for wear or dam-
age.
7. Remove the seal (6) from the bottom of the outlet
housing (19). Unscrew the packing nut (3). Remove
the glands and v-packings (T) from the housing. Do
not remove the outlet fitting (4) and o-ring (5) unless
they need replacement.
8. Unscrew the bleeder valve plug (35) completely
from the valve body (34). Clean the valve threads
and the bleed hole. It is not necessary to remove the
valve body.
CAUTION
To reduce the possibility of costly damage to the rod
(1) and cylinder (7), first place the cylinder on a soft
block of wood. Always use a rubber mallet or an arbor
press to drive the rod (1) out of the cylinder (7). Never
use a hammer to drive the rod.
311825L
9. Stand the cylinder (7) upright on a wooden block.
Using a rubber mallet or an arbor press, drive the
displacement rod (1) and piston assembly down into
the cylinder as far as possible, then place the cylin-
der on its side and continue to drive the rod out the
. 1.
IG
bottom until the piston comes free. Pull the rod and
piston from the cylinder, being careful not to scratch
the rod or cylinder.
Accessory Service Tools are available which fit
over the top of the displacement rod, making it eas-
ier to use a 24 in. adjustable wrench or 3/4 in. drive
socket when disassembling/assembling the rod
and piston.
•
•
10. Put the flats of the piston seat housing (12) in a vise.
Unscrew the rod (1) from the housing (12), leaving
the ball guide (9) assembled to the rod. Be careful
that the piston ball (10) doesn't fall as you separate
the housing (12) and ball guide (9).
11. Remove the glands and v-packings (P) from the pis-
ton seat housing (12). Inspect the ball (10) and ball
seat (B) on the housing (12) for wear or damage.
12. Inspect the outer surface of the displacement rod (1)
and the inner surface of the cylinder (7) for scoring
or wear; replace if damaged. If replacing the rod,
remove the ball guide (9) (see step 13).
Do not remove the ball guide (9) from the displace-
ment rod (1) unless either part needs replacement.
13. Place the flats of the ball guide (9) in a vise. Using a
24 in. adjustable wrench or 3/4 in. drive socket,
unscrew the rod (1) from the ball guide.
For Dura-Flo 1800 (430 cc) Lowers, order Part
No. 109507 Tool.
For Dura-Flo 2400 (580 cc) Lowers, order Part
No. 109508 Tool.
Repair
7