Graco 239877 Marine Sanitation System User Manual


 
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Air Motor and Throat Service
D Before you start, be sure you have all necessary
parts on hand. Repair Kit 206728 is available for
the motor. Use all the parts in the kit for the best
results. Parts included in the kit are marked with an
asterisk (*) in the parts drawing and list.
D Two accessory tools should be ordered. Use
Padded Pliers, 207579, to grip the trip rod without
damaging its surface. Use Gauge, 171818, to
ensure the proper clearance between the poppets
and seat of the transfer valve.
Disassembly
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 7.
1. Flush the pump.
2. Relieve the pressure before you proceed.
3. Disconnect the hoses, remove the pump from its
mounting, and clamp the air motor base (5) in a
vise.
4. Use a strap wrench or pipe wrench on the
extension tube (64) to screw it out of the base (5).
See Fig. 4.
5. Pull the extension rod (57) down as far as it will go,
exposing the displacement rod (8).
6. Use a hammer and punch to remove the roll pin
(74) from the displacement rod (8), and unscrew
the extension rod (57) out of the displacement rod.
CAUTION
In step 7, do not damage the plated surface of the
trip rod (11). A damaged trip rod could cause
erratic air motor operation. Use the special
padded pliers, 207579, to grasp the rod.
7. Manually push on the displacement rod (8) to
move the air motor piston (2) up as far as it will go.
Unscrew the cylinder cap nut (29a or 29b). Pull
the nut up. Grip the trip rod (11) with padded
pliers, and screw the nut off the rod. See Fig. 4.
8. Remove the six screws (21) that hold the cylinder
(17) to the base. Carefully pull the cylinder straight
up off the piston (2).
CAUTION
To avoid damaging the cylinder wall, lift the cylinder
straight up off of the piston. Never tilt the cylinder
while you are removing it.
WARNING
To reduce the risk of pinching or amputating your
fingers, always keep fingers clear of the toggle
assemblies (L). See Fig. 5.
9. Use a screwdriver to push down on the trip rod
yoke (22), and snap the toggles down. Remove
the lockwires (31) from the adjusting nuts (30) of
the transfer valves. Screw the top nuts off. Screw
the stems (1a) out of the grommets (12) and
bottom nuts. Take the valve poppets (1b) off the
stems and squeeze them firmly to check for
cracks. See Fig. 5.
10. Grip the toggle rockers (26) with a pliers.
Compress the springs (27), and swing the toggle
assembly (L) up and away from the piston lugs
(M), and remove the parts. Check to see that the
valve actuator (13) is supported by the spring clips
(14), but slides easily into them. See Fig. 5.
11. Remove the trip rod yoke (22), actuator (13), and
trip rod (11). Check the exhaust valve poppets
(16) for cracks.
NOTE: To remove cracked exhaust valve poppets
(16), stretch them out, and cut them with a sharp knife.
12. Remove one of the air motor plates (18 or 20).
Pull the piston (2) up out of the base (5). Remove
the throat packing nut (38) and throat seal (6).