8
SERVICE
Pump Repair Notes
1. Shut off the air to the pump, close the air control valve
and the bleed–type master air valve.
2. Disconnect the air and fluid hoses.
Reassembly Notes
1. The pump is marked with cast–in arrows (
Y
). Fig. 3
shows the location and direction the arrows must
face for proper reassembly.
2. The outlet manifold (on top of the pump) is marked
GRACO; the inlet manifold has no special markings.
Fig. 3
1” NPT
FLUID
OUTLET
1” NPT
FLUID
INLET
1/4 NPT
AIR INLET
CAST–IN
ARROW
CAST–IN
ARROWS
Repairing the Air Director Valve Assembly
(See Fig. 4)
NOTE:
The air director valve assembly (52) is replace-
able as a unit. Perform steps 1–3, then reassem-
ble using the new valve assembly (steps 14–18).
To disassemble and repair the existing air direc-
tor valve assembly, perform steps 1–18.
1. Remove the screws (35) and washers (36). Gently
tap the air inlet plate (37) from the top and bottom
with a plastic mallet to help loosen the assembly .
Then pull the assembly out of the pump housing.
2. Remove the valve caps (30 and 33).
3. Use a 5 mm hex key wrench to remove the screws
(39) from the valve block (32). Then remove the air
inlet gasket (38) and plate (37).
4. Unscrew the actuator pin (27), then slide the pilot
valve spool (28) out of the block (32).
5. Use a 3 mm hex key wrench to remove the four
screws (22). Tap the slide valve plate (23) with a plas-
tic mallet to loosen it, then remove the plate, gasket
(24), slide valve (25), and spring (26) from the valve
block (32).
6. Slide the valve spool (31) out of the valve block (32).
Check the o–rings (29) carefully and replace, if nec-
essary.
7. Clean all parts thoroughly and inspect for wear or
damage. If the pilot valve bore (S) has nicks, burrs, or
excessive wear, replace the valve block (32). Clean
the threads of the actuator pin (27) and the threads
inside the pilot valve spool (28) to remove the old
thread sealant.
Fig. 4
35
36
REF 32
39
38
37
33
24
23
22
25
27
REF 27
28
30
29
31
29
32
GREASE
RECESS
GREASE OUTSIDE OF
CAPS (30, 33) AND
SPRING (26) BEFORE
REASSEMBLING
SLOT
TORQUE TO
3.4–4.5 N.m
(2.5–3.3 ft–lb)
TORQUE TO
6.8–7.9 N.m
(5–5.8 ft–lb)
TORQUE TO
8.5–9.5 N.m
(6.2–7 ft–lb)
S
APPLY LOCTITE
r
NO. 222
TO THREADS
26
