Checking air conditioning circuit for leaky points - AR83.30-P-1209-01D

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WORKSHOP EQUIPMENT

WE58.40-Z-1002-20A

Air conditioning leak detector

Fig 1: Checking For Leakage With Air Conditioning Charged

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Checking for leakage with air conditioning charged

Start vehicle engine and switch on air conditioning
Check entire air conditioning circuit with probe on leak detector
In areas where leaky points are suspected stay a while
Leakage test with air conditioning discharged

On vehicles with empty air conditioning on which no obvious leakage can be detected by evacuation, check as follows:

Evacuate air conditioning.
Charge air conditioning with approx. 200 g of R134a refrigerant
Allow engine to idle , air conditioning ON
- If the A/C compressor does not switch on, activate with hand-held tester and allow to run for approx. 2 minutes.
Engine OFF
Charge air conditioning with additional quantity of nitrogen to a system pressure of approx. 20 bar
Find leakage with leak detector

CAUTION:

Do not evacuate nitrogen with recycling unit

Fig 2: Checking Leakage With Air Conditioning Discharged

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

Since refrigerant is heavier than air and flows downward, always hold the leak detector probe below the suspected leaky point.

Line connections, pipe joints, condenser and evaporator are the most frequent cause for refrigerant loss.