Graco 204464 B Series, Instructions-Parts List Manual

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Service (Model 204464)
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 5.
Before You Start
D
Have all necessary repair parts on hand. Recom-
mended spare parts are marked with an asterisk
(for example, 15*).
D
Use a compatible solvent to clean parts. Inspect
parts for wear or damage and replace as needed.
D
Flush the pump if possible. Stop the pump at the
bottom of its stroke. Relieve the pressure before
servicing any part of the system.
D
Disconnect the air and fluid hoses.
Servicing the Air Motor
WARNING
To reduce the risk of injury from trapped air pres-
sure when servicing the air motor, always remove
cylinder cap (13) from air cylinder (4) before remov-
ing air cylinder from base (9).
Air Valve and Piston Repair
1. If your pump has a motor shield (B), unscrew the
shield retaining screw (A) and lift the shield up and
off the air motor. See Fig. 3.
2. Unscrew the cylinder cap (5) from the cylinder
(21). To remove the spring (15), pry gently under
the coils in the direction of the helix. Check the
spring (15) and gasket (11) and replace as neces-
sary.
3. Unscrew the cylinder (21) from the air motor base
(20) and lift the cylinder straight up off the air
piston (1).
4. To unscrew the piston from the rod, refer to the
piston detail in Fig. 3. Use a pliers (D) on the air
exhaust plate (1e) and a wrench (C) on the piston
rod (3).
5. Remove the three capscrews (1a) and disas-
semble the piston (1). Clean all parts in a compat-
ible solvent and blow dry. Check for wear or dam-
age and replace as necessary. If any valve plate
spacers (1b) are damaged, replace all three to
maintain the proper clearance between the valve
plates (1d and 1e).
6. Remove the washer (17), lower spring (16), and
gasket (18). Inspect for wear or damage and
replace as necessary.
7. Disconnect the piston rod (3) from the pump
connecting rod and pull the piston rod up out of the
air motor base (20). Remove the o-ring (12*) and
seal (7*). Inspect and replace if necessary. Recon-
nect the piston rod (3) and the pump connecting
rod.
8. Reinstall the gasket (18*), spring (16*), and wash-
er (17). Reassemble the piston (1). Apply thread
sealant to the screws (1a*) and torque to 10–14
in-lb (1.3–1.6 N
S
m). Apply thread sealant to the
threads of the piston rod (3) and carefully screw
the piston (1) onto the rod. For final tightening,
refer to step 4 and the piston detail in Fig. 3. When
installed, there should be 0.032 in. (0.8 mm)
minimum clearance between the washer (17) and
the shoulder of the piston rod (3).
9. Reinstall the spring (15*) and gasket (11*) on the
cylinder cap (5) and screw the cap onto the cylin-
der (21). Check that the shield bezel (22) is in
place on the air motor base (20). Screw the cylin-
der into the base.
10. Reinstall the air motor shield (B) and secure with
the shield retaining screw (A).