PUMPS
SUB-SECTlON 4B
off the pump. Remove the cover O-ring (see Figure 4B-29).
REASSEMBLY. Reassemble the pump, with a preassem-
Pull and/or pry out the cover end cartridge as shown in
bled pumping cartridge, as follows:
1. Clamp the body in a vise or place it on blocks as at
disassembly.
3. Next, remove the four screws attaching the inlet housing
to the body. Lift off the inlet housing (see Figure 4B-31)
and remove the body O-ring. Turn the driveshaft to free the
cartridge and pull the cartridge from the body.
These are right hand rotation pumps. Check the rota-
tion of the new cartridge before installing it in the
4. Remove the large snap ring and pull the driveshaft and
pump. The direction of rotation arrow should point
bearing from the body. Drive the shaft seal and wiper out
in a clockwise direction when the cartridge is viewed
from the shaft end of the body. If it is necessary to remove
from the shaft end.
the shaft bearing, first remove the small snap ring. Then
press the shaft out of the bearing, while supporting the
2. Install the O-ring and back-up ring on the pressure plate
bearing inner race.
hub. Lay the body O-ring in the body groove, and install
the large back-up ring and O-ring on the cartridge. Carefully
install the cartridge in the body so one of the chamfers on
5. Remove the O-rings and back-up rings from the pressure
the cam ring will align with the inlet port when the inlet
plate. Remove the fillister head screws and lift off the wear
housing is installed.
plate. Note the position of the cam ring, rotor, and vanes to
assure correct reassembly. Separate the cam ring, rotor,
vanes, locating pins, and pressure plate.
3. Place the inlet housing over the cartridge so the locating
pins are properly engaged and the inlet is in the correct
position with respect to the body outlet. Install the four
screws and torque them to the values shown in Figure
INSPECTION AND REPAIR. Inspect and repair the fol-
4B-27.
lowing items :
4. Install the cover end cartridge, being certain the pins
1. Discard the shaft seal and all O-rings and back-up rings.
engage the inlet housing. Place the large back-up ring and
Use a new gasket kit for reassembly. Wash the metal parts
O-ring on the pressure plate.
in clean mineral solvent, blow them dry with filtered, de-
hydrated air, and place them on a clean surface for inspec-
5. Install the small O-ring and back-up ring on the pressure
tion.
plate hub. Install the cover O-ring in its groove. Install the
cover and screws. Tighten the screws to the torque values
shown in Figure 4B-27.
2. Check the wearing surfaces of the cartridge parts for
scoring and excessive wear. Remove light score marks by
lapping. Lubriting, Moly-Koteing or equivalent is desirable
after lapping to prevent seizure during start-up. Replace any
OVERHAUL
heavily scored or badly worn parts.
DISASSEMBLY. Use the following procedure in conjunc-
3. Inspect the vanes and inserts for burrs, wear, and exces-
tion with Figure 4B-27 to completely disassemble the
sive play in the rotor slots. Replace the rotor if the slots are
pump:
worn.
1. Support the pump on blocks or clamp the body. in a vise
as shown in Figure 4B-28. If a vise is used, use protective
4. Rotate the bearing while applying pressure to check for
wear, looseness and pitted or cracked races.
jaws to avoid damage to the body and its machined sur-
faces.
5. Inspect the seal and bushing mating surfaces on the shaft
for scoring or wear. Replace the shaft if marks cannot be
2. Mark the body, inlet housing, and cover for correct re-
removed by light polishing.
assembly. Remove the four cover screws and lift the cover
4B-19
