f. Adjustment. Adjust the impeller by installing or
removing the impeller adjusting shims (6, fig. 4-14).
a. Description. The water pump is mounted inside
Install shims until the impeller will rub against the vane
the water pump frame, and is operated by an electric
plane when it is installed. Remove 0.004 shim and
motor. It draws water through the suction strainer and
install impeller and vane plate. The impeller should turn
the hose, from the water source, and forces it through
freely without rubbing against the vane plate after the
the discharge hose to the water heater. On the pump
proper adjustment has been made.
housing a drain cock is located. It is used to drain the
g. Installation. Install the water pump drain cock
water from the pump.
by reversing the procedures in b above.
b. Removal.
(1) Remove the electric motor and the pump
from the pump frame (para 4-24d (1) thru (6)).
a. Control Panel Circuit Breaker Subassembly.
(2) Remove the nuts from the studs that hold
(1) Description.
A
circuit
breaker
the pump housing (9, fig. 4-10) to the bracket (5).
subassembly is a switch device which stops the flow of
(3) Separate the pump housing (2, fig. 4-12)
current in a continuous circuit when the circuit is
from the bracket (3) as illustrated in figure 4-12, and
overloaded. The instructions in this paragraph pertain to
remove the gasket from the bracket (3, fig. 4-13).
the circuit breaker subassembly either on the water
(4) Unscrew and remove the water line
heater or the water pump.
strainer (9, fig. 4-14),with the pipe nipple (10) and with
(2) Removal.
tee (13) from the housing (17).
(a) Remove the six screws (fig. 4-11)
(5) Remove the vane plate (21, fig. 4-14)
that secure the control panel box cover to the box, and
from the bracket (26), and remove the impeller (23)
separate the cover from the box.
from the motor shaft (paras 4-25b (2) thru (6)).
(b) Remove the screws that secure the
(6) Remove the shims (6), washer (24),
circuit breaker subassembly to the cover, and separate
mechanical seal (5), stationary seals (4 and 25) from the
the subassembly from the cover.
motor shaft.
(c) Turn
the
circuit
breaker
(7) Unscrew and remove the drain cock (8,
subassembly over to expose the wire connections as
shown in figure 4-16.
(d) Loosen the screws that attach the
c. Inspection.
(1) Inspect the housing for breaks, cracks and
wire connections to the circuit breaker subassembly.
damaged threads.
(e) Remove the wires from the circuit
(2) Inspect for broken, cracked or dirty
breaker subassembly.
impeller and vane plate.
NOTE
(3) Examine the mating surfaces of the seals
Tag the wires for identification if
to see that they are highly polished, and are not pitted,
color-coded wires are not used.
scratched and corroded.
(3) Inspection. Use an ohmmeter to check
(4) Inspect the drain cock for broken handle
for continuity across the terminals with the switch in the
and damaged threads.
ON position. Inspect for damaged threads and broken
d. Servicing. Clean dirt and foreign matter from
case.
the impeller and the vane plate.
(4) Installation.
Replace defective circuit
e. Repair. Replace a defective pump housing,
breaker subassembly with a serviceable one and install
vane plate or impeller. Repair the water pump by
it by reversing the procedure in a (2) above. Connect
installing a new water pump repair kit.
the wires according to the wiring diagram in figure 4-15
for the water pump.
4-22
