PUMPS
SUBSECTION 5B
4. Check for broken or cracked parts. This type of damage
can be caused by large metal objects or defective relief
valves (high pressure).
No force must be used when installing the
bushing assemblies into the body. If the bush-
5. If the bushings are worn, inspect the walls of the body
ing assemblies jam in the bore, remove and
where the gears rotate. Excessive wear in this area is cause
examine them for nicks or scratches. This type
for the replacement of the pump.
of damage can be removed with a fine grit hand
stone.
6. Inspect the gears for proper and even wear across each
tooth surface. If wear to the gears is excessive, replace the
3. Place the body on clean bench with the hollow dowels
pump.
facing up and install the flange end bushing assemblies into
the body. Note that the bushing lobes are facing in and the
7. Replace the shaft seal as described earlier in this sub-
recessed area is opposite the hollow dowels.
section.
4. Lay the pump on its side and slide drive gear shaft (12)
through the bore so the splined end protrudes from the
hollow dowel end of the body
ASSEMBLY. Assembly is basically the reverse of disas-
5. Install seal (14) as previously described under the head-
sembly. Install new O-rings, back-up washers, and lobe
ing SEAL REPLACEMENT.
seals. Coat all parts with clean hydraulic oil to facilitate as-
sembly and provide initial lubrication. Assemble the pump
6. Install O-ring (04). then slide mounting flange (13)
as follows (see Figures 5B-1 and 5B-2).
squarely onto the splined shaft taking care not to damage
seal (14).
1. Layout the bushing assemblies for the mounting flange
7. Carefully install driven gear (11).
and end cover as shown in Figure 5B-2.
8. Repeat steps 2 and 3 for the end cover assembly. Posi-
tioning of the bushing assembly is the same as described in
2. Fit the back-up washers onto lobe seals (07) of the bush-
step 3.
ing assemblies as shown in View "A-A" of Figure 5B-1.
9. Install the other O-ring into the body of the pump
NOTE
10. Align the marks made in disassembly and place end
When fitted correctly, the back-up washers must be
cover (03) against the body. Install the four capscrews with
level and flush with the top surface of the bushing
the lockwashers and torque to 36 ft-lbs.
lobes.
Figure 5B-2. Bushing Assembly Installation
5B-4
