Graco 253485 User Manual

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Service
Bearing and Air Gasket Removal
Tools Required
D Torque wrench
D 10 mm socket wrench
D Bearing puller
D O-ring pick
D Press, or block and mallet
Disassembly
NOTE: Do not remove undamaged bearings.
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 12.
1. Relieve the pressure.
2. Remove the manifolds and disassemble the ball
check valves as explained on page 18.
3. Remove the fluid covers and diaphragm assem-
blies as explained on page 19.
NOTE: If you are removing only the diaphragm shaft
bearing (19), skip step 4.
4. Disassemble the air valve as explained on page
16.
5. Using a 10 mm socket wrench, remove the screws
(25) holding the air covers (23) to the center
housing (1). See Fig. 14.
6. Remove the air cover gaskets (22). Always replace
the gaskets with new ones.
7. Use a bearing puller to remove the diaphragm
shaft bearings (19), air valve bearings (12) or pilot
pin bearings (15). Do not remove undamaged
bearings.
8. If you removed the diaphragm shaft bearings (19),
reach into the center housing (1) with an
o-ring pick and hook the u-cup packings (402),
then pull them out of the housing. Inspect the
packings. See Fig. 13.
Reassembly
1. If removed, install the shaft u-cup packings (402*)
so the lips face out of the housing (1).
2. The bearings (19, 12, and 15) are tapered and can
only be installed one way. Insert the bearings into
the center housing (1), tapered end first. Using a
press or a block and rubber mallet, press-fit the
bearing so it is flush with the surface of the center
housing.
3. Reassemble the air valve as explained on page
17.
4. Align the new air cover gasket (22) so the pilot pin
(16) protruding from the center housing (1) fits
through the proper hole (H) in the gasket.
5. Apply medium-strength (blue) LoctiteR or equiva-
lent to the threads of screws (25). Align the air
cover (23) so the pilot pin (16) fits in the middle
hole (M) of the three small holes near the center of
the cover. Install the screws (25), handtight. See
Fig. 14. Using a 10 mm socket wrench, torque the
screws oppositely and evenly to 130 to 150 in-lb
(15 to 17 NSm).
6. Install the diaphragm assemblies and fluid covers
as explained on page 19.
7. Reassemble the ball check valves and manifolds
as explained on page 18.

Graco 253485 Specifications

General

Brand	Graco
Model	253485
Category	Water Pump
Language	English