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Dehydrating Sealed Refrigeration System; Brazing; Refrigerant Precautions; Open Lines - 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.

Dehydrating Sealed Refrigeration System

It is a misconception that moisture in a sealed refrigerant
system is harmless. Moisture in a sealed refrigerant
system, when exposed to heat generated by the
compressor and motor, reacts chemically with refrigerant
and oil in the system and forms corrosive hydrochloric
and hydrofluoric acids. These acids contribute to the
breakdown of motor winding insulation and corrosion of
compressor working parts, causing compressor failure.
In addition, sludge, a residue of the chemical reaction,
coats all surfaces in the sealed system, and will
eventually restrict refrigerant flow through the capillary
To dehydrate the sealed system:
1. Perform the leak test.
2. Capture refrigerant in system.
NOTE: It is the responsibility of the service technician to
capture refrigerant in system for safe disposal,
before opening any refrigeration system.
3. Repair any leaks in system.
4. Evacuate system.
5. Recharge to specification with new refrigerant.
NOTE: Do not use captured or recycled refrigerant in
units. Captured or recycled refrigerant voids any
compressor manufacturers warranty.


Brazing requires high temperatures. Take all
necessary precautions to protect against personal
injury and property damage.
Satisfactory results require cleanliness, experience, and
use of proper materials and equipment.
Connections to be brazed must be properly sized, free of
rough edges, and clean.
Generally accepted brazing materials are:
• Copper to copper joints: SIL-FOS (alloy of 15%
silver, 80% copper, and 5% phosphorous). Use
without flux. Recommended brazing temperature is
approximately 1400°F. DO NOT USE FOR COPPER
• Copper to steel joints: SILVER SOLDER (alloy of
©2004 Maytag Services
To avoid risk of electrical shock, personal injury or death,
always disconnect electrical power source to the freezer
30% silver, 38% copper, 32% zinc). Use with fluoride
based flux. Recommended brazing temperature is
approximately 1200°F.
• Steel to steel joints: SILVER SOLDER (see above).
• Brass to copper joints: SILVER SOLDER (see
copper to steel connections).
• Brass to steel joints: SILVER SOLDER (see copper
to steel connections).

Refrigerant Precautions

To avoid personal injury do not allow refrigerant to
contact eyes or skin. Do not burn refrigerant.
Do not use refrigerant other than that shown on unit
serial number identification plate.
NOTE: All precautionary measures recommended by
refrigerant manufacturers and suppliers apply
and should be observed.

Open Lines

During any processing of refrigeration system, never
leave lines open to the atmosphere. Open lines allow
water vapor to enter system, making proper evacuation
more difficult.

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