Bearing Housing & Connecting Rod Replacement - Graco ultra 750 Instruction Manual

BEARING HOUSING & CONNECTING ROD REPLACEMENT
WARNING
Before doing this procedure, follow the Pressure
Relief Procedure Warning on page 24 to reduce
the risk of a fluid injection injury , splashing in the
eyes or in the skin, injury from moving parts or elec-
tric shock. Unplug the sprayer!
C
PACKING WITH
BEARING GREASE
68
25
B
TORQUE TO
175 IN–LB
OIL
(19 N.M)
23
49
24
42
43
47
76
Fig 34–1
NOTE: Stop the sprayer at the bottom of its stroke to get
the crank (E) in its lowest position.T o lower the
crank manually, carefully rotate the blades of the
fan with a screwdriver.
1. Remove the front cover (49). Hold a wrench on the
pump intake valve and unscrew the pump suction
tube. Disconnect the short hose (70) from the pump.
2. Push up the retaining spring (42). Push the pin (43)
out the rear.
3. Loosen the pump jam nut (47). Unscrew the dis-
placement pump (76).
4. Remove the four screws (25) and lockwashers (23)
from the bearing housing (69).
5. Lightly tap the lower rear of the bearing housing (69)
with a plastic mallet to loosen it from the drive hous-
ing (67). Pull the bearing housing and the connecting
rod assembly (68) straight off the drive housing.
6. Remove the pail bracket assembly (F) and reinstall
it on the new bearing housing.
7. Inspect the crank (E) for excessive wear and replace
parts as needed. Evenly lubricate the inside of the
bronze bearing (B) with high quality motor oil. Liber-
ally pack the roller bearing (C) with bearing grease.
307–786
67
E
69
F
70
40
8. Assemble the connecting rod (68) and bearing hous-
ing (69).
9. Clean the mating surfaces of the bearing and drive
housings.
10. Align the connecting rod with the crank (E) and care-
fully align the locating pins in the drive housing with
the holes in the bearing housing (69). Push the bear-
ing housing onto the drive housing or tap it into place
with a plastic mallet.
CAUTION
DO NOT use the bearing housing screws (25) to try
to align or seat the bearing housing; the bearing and
drive housing will not align properly and will result in
premature bearing wear.
11. Install the screws (25) and lockwashers (23) in the
bearing housing. T ighten the screws evenly to
175 in–lb (19 N.m).
68
FACE OF
BEARING
HOUSING
Fig 34–2
12. Screw the displacement pump 3/4 of the way into the
bearing housing (69). Hold the pin (43) up to the pin
hole in the connecting rod (68). Screw in the pump
until the pin slides easily into the hole. Back of f the
pump until the top threads of the pump cylinder are
flush with the face of the bearing housing and the out-
let adapter (A) is facing back. Push the
spring (42) into the groove all the way around the
connecting rod. Tighten the locknut (47) very tight –
about 70 ft–lb (95 N.m) – with a 2 in. open end wrench
and a light hammer. See Fig 34–2.
WARNING
Be sure the retaining spring (42) is firmly in the
groove all the way around, to prevent the pin (43)
from working loose due to vibration. See Fig 34–2.
If the pin works loose, it or other parts could break
off due to the force of the pump action. These parts
could be projected through the air and result in seri-
ous bodily injury or property damage, including dam-
age to the pump connecting rod or bearing housing.
13. Install the front cover (49). Connect the suction tube
(86) and short hose (70) to the pump. See Fig 34–1.
43
42
69
47
TORQUE TO
70 ft–lb
(95 N.M)
retaining