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Refrigerant Leaks - Maytag AFU1202BW Service

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before attempting to service unless test procedures require power to be connected. When removing any wiring from
terminals, replace on the same terminals. Ensure all ground wires are connected before certifying unit as repaired
and/or operational.

Refrigerant Leaks

Free oxygen will explode on contact with oil. Acetylene
will explode spontaneously when put under pressure.
To prevent violent explosions that may result in
serious injury or death to persons in or near the
immediate vicinity, NEVER use oxygen or acetylene
for pressure testing or cleanout of refrigeration
Before attempting to locate a leak, study the diagrams
showing the route of refrigeration tubing and serviceable
NOTE: Urethane foam cells are filled with trapped gas
and if cells are broken (by removing a piece of
foam, etc.) a leak detector will indicate a strong
leak. When foam cells are broken, liberated gas
should be blown off surface or allow unit to
stand for at least 5 minutes before testing.
Symptoms of refrigerant leaks
1. Frost-line, visible inside food-liner, does not extend to
tail-end of evaporator. In properly refrigerated system
frost-line, on the food-liner back wall of the chest
freezer, will extend down to 5–6 inches from the food-
liner bottom. In slow leaks, this frost-line gradually
recedes upward.
When an internal refrigerant leak is suspected,
recharge freezer with proper amount of refrigerant
and mark end of the frost-line (nearest spot to the
bottom) with a crayon. Leave freezer running
(sometimes for months) and observe mark
periodically. If frost-line moves away from mark, a
leak (external or internal) is certain.
2. Feeler bulb of thermostat, is located toward tail-end of
evaporator. In case of shortage in refrigerant, tail-end
of evaporator will not be refrigerated and thermostat
will not cut out causing freezer to run continuously.
(This can be confused with a faulty thermostat.)
3. Although compressor is running continuously, food-
liner temperature will rise.
4. Low suction pressures.
External Or Internal Leak
• "Internal leaks" are refrigerant leaks inside foam
insulation. All other leaks are considered "external".
• Once presence of a leak has been determined (from
symptoms described above), locate leak.
• First, test all joints in compressor compartment. Hold
©2004 Maytag Services
To avoid risk of electrical shock, personal injury or death,
always disconnect electrical power source to the freezer
nozzle of detector on every joint for at least 1 minute.
If no leak can be found at these joints, check for
internal leak.
Finding Internal Leak
Confirm existence of an internal leak by pressure testing.
NOTE: For this test, evaporator and condenser must be
disconnected and individually pressure tested
with dry air or dry nitrogen at pressures between
200–300 psi.
Leave the components under pressure for a minimum of
3 days. If after 3 days, pressure drop is more than 10
psig, at approximately same room temperature,
presence of an internal leak can be assumed.
• Be sure there are no leaks in connections between
pressurizing device and gauge or between gauge and
cabinet. A leak at these joints could be misinterpreted
as an internal leak.
• Apply soap solution to all joints and connections to
check for leaks (bubbles).
• If pressure drop after 3 days is not more than 10 psig,
there is no internal leak.
Pressure test described above will indicate:
• leaking condenser; or
• leaking evaporator; or
• no leak.
Condenser Leak (Internal)
If indications are that internal leak is in condenser, leak is
considered to be nonrepairable. If unit is under warranty,
contact factory for permission to replace unit.
Evaporator Leak (Internal)
If pressure test indicates leak in the evaporator, the leak
could be:
• at the evaporator/suction line; or
• at the evaporator inlet joints, or
• at an unknown location.
Joint is located approximately 2–4 inches below breaker
strip at back left corner. After breaker strip has been
removed, carefully search for capillary by gradually
removing foam insulation.
Evaporator inlet can be lifted above cabinet flange for
examination and repair. After leak has been repaired,
repack void with fiberglass insulation.
NOTE: Removal of breaker strip will destroy it. Replace
breaker strip with new one.
If evaporator leak is at unknown location, contact factory
for permission to replace unit if product is under

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