Section 22: HEATING AND AIR CONDITIONING
PA1562
42
9.7 WATER RECIRCULATING PUMP
This vehicle is provided with a water
recirculating pump which is located in the
evaporator compartment (Fig. 45). The water
recirculating pump consists of a centrifugal
pump and an electric motor which are mounted
in a compact assembly.
FIGURE 45: PUMP LOCATION (CENTRAL A/C) 22331
The (seal less) pump requires no periodic
maintenance other than replacement of motor
brushes. Replacement of motor brushes can be
performed without removing the pump
assembly. Inspection of the pump, to determine
if the pump is working properly, should be made
while the pump is in operation. If there is
evidence that the pump is not operating as per
specifications, the unit must be disassembled for
corrective measures.
Disassembly of the pump will be necessary only
in the case of a rotor failure or motor failure.
9.7.1 Removal
1. Stop engine and allow engine coolant time
to cool.
2. Close shutoff valves. Refer to "05
COOLING" under heading "Draining
Cooling System" for location of valves.
3. Disconnect the electrical wiring from the
motor.
WARNING
Before proceeding with the following steps,
check that coolant has cooled down.
4. Disconnect water lines from pump at flange
connections. Place a container to recover
the residual coolant in the line.
5. Remove the two clamps holding the pump
motor to its mounting bracket. Remove the
pump with the motor as an assembly.
9.7.2 Disassembly
1. Separate the housing (1) from the adapter
(7) by first removing the 4 capscrews.
Remove housing carefully to prevent
damaging the O-ring (2).
2. Remove rotor assembly (4), washers (3)
and shaft (5) from the adapter.
Inspection
Components removed from the recirculating
pump and motor assembly should be compared
with new parts to determine the degree of wear.
9.7.3 Brushes
1. When removing brushes, note the position
of the brush in the tube. Brush life is
shortened if the brushes are not replaced
properly.
2. Examine brushes for the following:
a. Wear
Replace the brushes if less than 25%
of the usable brush is left (less than
0.300 inch [8 mm]).
b. Chipped edges
Chips can be caused by improper
handling or installation. Badly chipped
brushes should be replaced regardless
of their length.
c. Annealed brush spring
This can be detected by noting the
resiliency of the spring. Annealing is
caused by failing to tighten the brush
caps properly, thus not providing a
good low resistance contact between
the terminal and the brush tube.
Replace brushes showing evidence of
annealed springs.
d. Frayed or broken pigtail
An improperly installed brush may
have the pigtail (shunt) pinched under
the terminal or between the coils of the
spring. If the pigtail is badly frayed or
broken, replace the brush.
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