Sanyo ASW U1100T, Service Manual

Page: 20 / 29

- 19 -
13. Troube shooting of Bearing Assembly (Bearing Case Complete)
For Fully Automatic Washing Machines.
1.
Abnormal (Squeaky) sound is heard during washing:
Symptom: The squeaky sound occurs when the brake system operates. During washing, the Pulsator turns
CW (clockwise) and CCW (counterclockwise), producing water flow in the CW and CCW
direction. The water flow exerts force on the Spin Tub in the same directions though interlocked
with the Brake Wheel during washing. The Spin Tub turns a little if the friction with the brake
lining reduces, generating braking sound. This symptom will not arise due to use of long
duration but is entirely an initial fault.
Diagnosis: Turn off the power. Open the Washer Lid. Hold the Spin Tub and lightly turn it CW. If sound is
heard from the brake, it is defective.
Cause: The cause can be limited to foreign substance (grease in particular) affixed to the surface of
brake lining and brake wheel, which is attributed to poor quality control in the Bearing Assembly
manufacturing process.
Handling: Replace the Bearing Case (complete) and wipe the Brake Wheel surface with alcohol.
2.
Spin tub stops sound (squeak):
Symptom: Squeaky sound is heard immediately before the Spin Tub stops.
Cause: This symptom often arises when friction factor between brake lining and brake wheel is too big.
Therefore, this occurs when brake time is short, the cause of which is attributed mainly to the
improperness of brake lining material, roughness of brake wheel surface and excessive
strength of brake spring, but attachment of foreign matter and high humidity can also be
responsible for the symptom.
Diagnosis: Allow water extraction program to complete automatically instead of forcibly, apply the brake,
and listen for squeaky sound when the Spin Tub stops.
Handling: Replace the Bearing Case (complete) and wipe the Brake Wheel surface with alcohol.
3.
Brake does not work:
Symptom: Brake is applied when water extraction has completed, but the Spin Tub takes too long time to
come to a complete stop.
Cause: Braking torque is too small, which is attributed to excessive abrasion of brake lining, attachment
of foreign substance (grease in particular) on the surface of brake wheel and brake lining, etc..
Diagnosis: Taking approx 10 sec. of braking time, which is normally about 5 sec, can be determined to be
defective.
Handling: Replace the Bearing Case (complete) and wipe the Brake Wheel surface with alcohol.
4.
Abrupt braking (When the Spin Tub stops, the entire machine moves):
Symptom: Brake is applied when the water extraction has complete, but the Spin Tub takes a very short
time to come to a complete stop.
Cause: Braking torque is too big, which is attributed to abnormal shape of brake lining. This symptom
occurs particularly when clearance between brake lining and brake wheel is too small at their
tips.
Diagnosis: Taking only 2 or 3 sec. of braking time, which is normally about 5 sec at no load, can be
determined to be defective.
Handling: Replace the Bearing Case (complete) and wipe the Brake Wheel surface with alcohol.