Service - Graco President L Series Technical Data Manual

Servicing the Air Motor
Before you Start
D Be sure you have all necessary parts on hand. Air
Motor Repair Kit 207385 includes repair parts for
the motor. Use all the parts in the kit for best
results. Parts included in the air motor kit are
marked with double asterisks (**) in text and
drawings. See the parts list and drawing for your
pump (pages 14 to 22) for further information.
D Two accessory tools should be used. Padded
pliers, 207579 is used to grip the trip rod without
damaging its surface. Gauge, 171818, is used to
ensure the proper clearance between the poppets
and seat of the transfer valve.
Disassembly
1. Flush the pump. Follow the Pressure Relief
Procedure Warning, at left, before proceeding.
2. Disconnect the air hose from the motor. If
necessary, disconnect the motor from the pump.
Clamp the air motor base in a vise.
3. Manually push up on the piston rod to move the
piston assembly to the top of its stroke. Unscrew
the cylinder cap nut (F) from the cylinder (G). Pull
up on the cap nut. Grip the trip rod (H) with
padded pliers 207579 and screw the cap nut off
the trip rod. See Fig. 2.
CAUTION
Do not damage the plated surface of the trip rod.
Damaging the surface of the trip rod can result in
erratic air motor operation. Use the special padded
pliers, 207579, to grasp the rod.
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Service

4. Remove the eight screws (Z) holding the cylinder
(G) to the base (J). Carefully pull the cylinder
straight up off the piston. See Fig. 2.
To avoid damaging the cylinder wall, ALWAYS lift the
cylinder straight up off of the piston. Never tilt the
cylinder as it is being removed.
Always keep fingers clear of the toggle assemblies
(E), to avoid pinching or amputating them. See
Fig. 3.
5. Use a screwdriver to push down on the trip rod
yoke (K) and snap the toggle assemblies (E)
down. See Fig. 3. Remove the lockwires (L) from
the adjusting nuts (M and Q) of the transfer valves
(N). Screw the top nuts (M) off. Screw the valve
stems (O) out of the grommets (P) and lower
adjusting nuts (Q). Take the valve poppets (R) off
the stems and squeeze them firmly to check for
cracks.
Hold trip rod with
padded pliers
207579, to prevent
damage to rod
BB
Fig. 2
CAUTION
WARNING
H
Z
F
G
J