Figure 7-1.Typical washer motor.
motor with pulleys, mounting bracket, and high-speed
Pump.The pump removes water from the tub
after each cycle. Normally, the pump is located next to
the motor and is engaged by the electrical solenoid. The
solenoid engages the friction wheel of the pump (fig.
7-2) with the friction wheel on the motor, causing the
shaft to turn the impeller and extract water from the tub.
The discharge hose of the pump must be mounted above
the water level of the tub, or the water will dram without
the operation of the pump. In some cases, the pump is
belt-driven and the solenoid tightens the belt to make
the pump operate.
One of the major causes of pump failure is foreign
objects lodged in the pump impeller. To correct this
situation, you remove the cover clamp (fig. 7-2) and the
cover and remove the lodged item from the pump.
Other causes are slippage between the friction wheels of
the pump and motor and failure of the solenoid. Also,
check for clogged hoses leading to and from the pump.
Inlet Valves.Water inlet valves equipped with
two solenoids are called mixing valves. They have two
water inlets: one hot and one cold. They actually mix
hot and cold water. When the temperature control
switch is set in the HOT position, the solenoid on the
hot-water side of the valve is energized. That permits
only hot water to enter the machine. Conversely, when
the temperature control switch is set in the COLD
position, the solenoid on the cold-water side of the valve
is energized, and only cold water is permitted to enter.
Positioning the switch in the WARM position energizes
both solenoids, allowing hot and cold water to mix.
When water fails to enter the machine naturally,
check the water supply first. Then check the screen at
the inlet valve. At the hose connection to the inlet valve,
there is a fine screen: make sure it is free of any foreign
Figure 7-2.Pump assembly.
objects. Ensure that you have power to the inlet valve
solenoid. Remember the electrical power must come
through the water-level control switch, water-
temperature selector switch, and timer.
As a last resort, disassemble the valve and check for
foreign objects. Also, ensure that the plunger inside the
valve is free to operate; there must be at least 10 pounds
of water pressure to overcome the spring pressure of the
plunger in the solenoid valve.
Water-Level Switch.The water-level switch,
normally actuated by pressure, controls the amount of
water that enters the tub. The switch has an adjustment
screw to set the level of the water. The tighter the screw,
the more pressure is required to operate the switch, and
the higher the water level required The water-level
switch has two sets of contacts, one normally opened
and the other normally closed. As the correct water
level is reached, the switch opens one set of contacts,
de-energizing the water fill valve. The other set of
contacts closes and completes a circuit to the timer,
allowing the timer to operate and start the next cycle.
The timer will not operate during the fill cycle.
Safety Switches.Most washers have at least two
safety switches. One is an off-balance switchthat opens
a circuit to the motor if the clothes shift to one side.
Moving the tub to the center and rearranging the clothes
will close the switch, allowing the washer to operate.
This switch prevents damage to the machine from the
vibration of operating with an unbalanced load The
other safety switch is located near the door of the
machine. Opening the door will stop the machine from
operating. Some machines do not have this switch but
have a locking solenoid. When the machine goes into
the spin cycle, the solenoid latches the door to keep it
from being opened during the spin cycle.