Specifications

13
BMB/BMC
Series
Assembly
Considerable care should be taken to
prevent wedging or jamming. Never
force the parts together. They will drop
into place if properly aligned.
1) Provide a can of clean oil, preferably
SAE-50 motor oil or mineral oil.
2) Fix Body (1) in a bench vise, inside
face up. Install Port Seal Screws (24 &
26) with new Gaskets (25 & 27).
3) Lubricate Arbors (10). If the Arbors
and Sleeve Bearing were removed,
press Arbors into the Pump Body (1)
using a Driven Metering Gear (6) as a
guide for pressing arbors perpendicular
(upright) to the plate. Reinstall Sleeve
Bearing lead end first into Body (1)
and press in place allowing Sleeve
Bearing to project from inside face
slightly less than the thickness of the
Port Plate (5).
Caution: Extreme care must be taken
with arbors when pressing out
of or installing into cast body.
4) Carefully place Port Plate (5) over
Arbors (10) making sure ports line up
with ports in Body (1). Make sure plate
is not 180° out of position; relief grooves
face up toward Center Plate (4).
5) Assemble Driving Metering Gear (7),
Round Key (12) and Drive Shaft (8).
6) Lubricate Sleeve Bearing and place
Driving Metering Gear assembly into
Body (1) and through Sleeve Bearing.
Rotate several times to insure free
rotation.
7) Place one Driven Metering Gear (6)
on its arbor and rotate several times
to be sure it is free. Repeat process
for the other Driven Metering Gear (6).
8) Rub a slight amount of oil over gear
recesses of the Center Plate (4), then
carefully lower over the Metering
Gears.
9) Put a drop of oil in the port recesses
on either side of the meshing point of
the gears. Turn the shaft to make sure
the gears turn freely.
10) Place Rear Side Plate (3) over
Center Plate (4) and screw in Binder
Screws (28) finger tight. Again, make
sure pump turns freely.
11) Tighten the Binder Screws (28) to
150 lbs.-in., 50% of the recommended
tightening torque. Follow the order
shown in Figure 7. Make sure the
pump turns freely.
12) Tighten Binder Screws (28) (following
the order shown in Figure 7) to rec-
ommended tightening torque of 305
lbs.-in. and make sure pump turns
freely.
Note: If the pump will not turn freely after
each component is installed, then
the last piece installed needs addi-
tional attention or replacement.
13) Turn the pump over (so the Drive
Shaft is facing upward) and clamp on
edges of Rear Side Plate (3) in vise.
14) Use of a Zenith
®
Lip Seal Installation
Guide (Bullnose) is recommended to
prevent seal damage. Place a new
Lip Seal (15) over the Bullnose with
spring-loaded open end facing down
and push down firmly to slightly
expand Lip Seal inside diameter.
See Figure 8.
Caution: Do not push the Lip Seal com-
pletely down the bullnose or
permanent damage to the seal
may result.
15) Remove Lip Seal from Bullnose and
attempt to slide Lip Seal onto Drive
Shaft.
16) If the seal does not slip on easily,
repeat Step 14, being careful not to
over-expand the Lip Seal. (The seal
will soon recover from the slight
expansion necessary.)
17) Once the Seal is installed onto the
Drive Shaft, place the Seal Plate (16)
into position as shown in Figure 9.
18) Install the three Seal Plate Screws
(20) and tighten evenly to draw the
Lip Seal into the pump body, being
careful not to cock the seal or damage
it in any way. See Figure 9.
19) Torque the three Seal Plate Screws
(20) to 50 lbs.-in.
20) Reinstall Outer Drive Gear (2) with
relieved side upward. Replace
External Locking Retaining Ring (30)
onto Drive Shaft (8).
21) Install Drive Strap (31) and Drive
Strap Screws (32).
22) After pouring oil into the inlet port,
rotate pump to lubricate internal
components and check for free
rotation.