64 51 ... Leak-testing evaporator

WARNING: This page is about a different car, the 2010 BMW M3, 2009 BMW M3, and 2008 BMW M3. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

64 5 121
64 5 124

See HEATING AND AIR CONDITIONING - SPECIAL TOOLS .

WARNING: It is essential, when handling nitrogen, to observe the standard national safety regulations.
Ensure that employees are advised of how to handle pressurized vessels and nitrogen correctly (danger of asphyxiation). For this purpose, follow the notes and instructions in the technical safety specifications available from the gas supplier.

Necessary preliminary tasks:

Remove expansion valve

Replace sealing rings (1) and coat with refrigerant oil

Fig 1: Identifying Sealing Rings

Courtesy of BMW OF NORTH AMERICA, INC.

Screw down special tool 64 5 124 with retaining clip (1).

Tightening torque 64 53 13AZ , see 64 53 REFRIGERANT LINES AND EXPANSION VALVE .

Fig 2: Identifying Retaining Clip

Courtesy of BMW OF NORTH AMERICA, INC.

Connect special tool 64 5 124 to special tool 64 5 121 .

Fig 3: Connecting Special Tool (64 5 124)

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Risk of damage: Use only nitrogen pressure bottles with pressure reducers for leak-testing.
Pressurize evaporator to 10 bar slowly only. Excessively fast pressurization and pressures in excess of 20 bar may cause damage to the evaporator.

Connect nitrogen pressure bottle with pressure reducer to pressure gauge and then connect to special tool 64 5 121 (connecting hose).

NOTE:

Testing apparatus must be leakproof.
Ambient temperature and temperature of vehicle must not change during the test procedure.
Do not move the vehicle during this period

Apply test pressure of 10 bar slowly and close nitrogen pressure bottle.

Check leak-tightness of testing apparatus and of connection to refrigerant line.

Set test pressure of 10 bar is only permitted to drop by 2 bar to 8.5 bar over a test period of 1.5 hours.

If the pressure loss is greater than 1.5 bar, this indicates that there is a leak in the evaporator unit.

WARNING: After leak-testing, unscrew special tool 64 5 121 slowly from special tool 64 5 124 to reduce pressure.

After leak-testing:

Replace all sealing rings and moisten with refrigerant oil