Refrigerant Circuit, Determining Leaks
Refrigerant Circuit, Determining Leaks
Refrigerant Circuit, Tracing Leaks with Electronic Leak Detector V.A.G 1796
Refrigerant Circuit, Tracing Leaks with Electronic Leak Detector V.A.G 1796
NOTE:
- Currents of air quickly disperse refrigerant gas. Draughts must therefore be avoided during leak detection.
- If the refrigerant circuit is completely empty, charge with about 100 g of refrigerant.
Leak detection:
- Start up leak detector in line with relevant operating instructions.
- Always hold test probe beneath suspected leak.
Depending on the model, leak detection is indicated by an increase in clicking rate or a warning tone (refer to operating instructions for leak detector).
Refrigerant Circuit, Locating Leaks with Leak Detection System VAS 6201
NOTE:
- Certain leaks are difficult or even impossible to locate using an electr. leak detector. In such cases, use can be made of the leak detection system VAS 6201.
- Refrigerant circuit leaks result in a loss of refrigerant oil together with the refrigerant. This oil generally remains in the vicinity of the leak location. Adding a small quantity of fluorescent fluid to the refrigerant circuit makes this oil visible under UV light. The fluid (PAG oil containing an additive which shows up under UV light) is poured into the refrigerant circuit and becomes distributed with the refrigerant oil when the air conditioner is switched on.
- The air conditioner must be operated for at least 60 min. to distribute the additive throughout the refrigerant circuit (compressor must run).
- The refrigerant oil containing the additive (which shows up under UV light) can either be poured directly into the open circuit or pumped in with the circuit charged using the hand pump VAS 6201/1 (from leak detection system VAS 6201) via the service connection on the low-pressure side.
- If the leak detection additive is applied via the service connection on the low-pressure side with the refrigerant circuit charged, a small quantity of additive remains in the service connection. This is to be carefully removed so as to avoid subsequent erroneous leak detection.
- If a component forming part of a circuit into which the leak detection additive is poured has to be replaced, thoroughly clean joints with other components after assembling refrigerant circuit. Otherwise, the remnants could lead to erroneous leak detection.
- On discharging the refrigerant circuit, refrigerant oil and thus also leak detection additive enters into the A/C service station. The oil is removed from the refrigerant in the oil separator of the A/C service station and discharged from the A/C service station via the drain. The refrigerant oil drained off is not to be poured back in. It is to be replaced with fresh refrigerant oil.
- Pay attention to the following if leak detection fluid has already been poured into a refrigerant circuit in the course of previous repair work: Only add new leak detection fluid if refrigerant oil is replaced. If only some of the refrigerant oil has been replaced, just add the corresponding quantity of leak detection fluid. If, for example, 100 ml of refrigerant oil has been replaced on a vehicle containing 250 ml, only add 1 ml (cu.cm) of leak detection additive.
- Certain materials and their compounds (e.g. oxidation products on aluminium components, anti-corrosion waxes) also show up under UV light.
Tools and other items required:
1. Hand pump with low-pressure service hose, service coupling and non-return valve VAS 6201/1
2. Cartridge VAS 6201/2
3. Cleaning agent VAS 6201/3
4. UV leak detection lamp VAS 6201/4
5. UV-absorbing safety goggles VAS 6201/6
6. Sticker VAS 6201/7
7. Tube VAS 6201/8 VAS 6201/8
8. Protective gloves VAS 6201/9
Pouring in leak detection additive with refrigerant circuit empty
The cartridge - A - contains 15.4 ml of leak detection additive (one unit - B - corresponds to 2.5 ml).
- Assemble hand pump VAS 6201, item - 1 - with cartridge, item - 2 - VAS 6201/2 .
- Insert tube VAS /8 (item - 7 - ) in hand pump.
- Open hand pump service valve.
With refrigerant circuit empty, the leak detection additive can best be poured in via an open connection.
- Open the refrigerant circuit at a readily accessible connection.
- Cover the surrounding area with sheeting or absorbent paper.
- Hold tube upwards.
- Screw in toggle of hand pump until leak detection additive emerges from tube.
- Fill the refrigerant circuit with 2.5 / - 0.5 ml (milliliter = cm) of leak detection additive.
- Replace O-ring at open connection.
- Assemble refrigerant circuit.
- Affix sticker next to service connections to indicate that leak detection fluid has been added to the refrigerant circuit.
- Evacuate and charge refrigerant circuit as specified.
NOTE:
- Pay attention to the following if leak detection fluid has already been poured into a refrigerant circuit in the course of previous repair work: Only add new leak detection fluid if refrigerant oil is replaced. If only some of the refrigerant oil has been replaced, just add the corresponding quantity of leak detection fluid. If, for example, 100 ml of refrigerant oil has been replaced on a vehicle containing 250 ml, only add 1 ml (cu.cm) of leak detection additive.
- The air conditioner must be operated for at least 60 min. to distribute the additive throughout the refrigerant circuit (compressor must run).
- Depending on the magnitude and location, it may take several days for sufficient refrigerant oil and additive to emerge to clearly identify the leak.
Leak Detection Additive, Adding with Refrigerant Circuit Charged
NOTE:
- Pay attention to the following if leak detection fluid has already been poured into a refrigerant circuit in the course of previous repair work: Only add new leak detection fluid if refrigerant oil is replaced. If only some of the refrigerant oil has been replaced, just add the corresponding quantity of leak detection fluid. If, for example, 100 ml of refrigerant oil has been replaced on a vehicle containing 250 ml, only add 1 ml (cu.cm) of leak detection additive.
- A small quantity of leak detection additive remains in the service connection. This is to be carefully removed so as to avoid subsequent erroneous leak detection.
- The air conditioner must be operated for at least 60 min. to distribute the additive throughout the refrigerant circuit (compressor must run). Depending on the magnitude and location, it may take several days for sufficient refrigerant oil and additive to emerge to clearly identify the leak.
The cartridge - A - contains 15.4 ml of leak detection additive (one unit - B - corresponds to 2.5 ml).
- Switch off ignition.
- Remove cap from service connection on low-pressure side of refrigerant circuit.
- Assemble hand pump VAS 6201, item - 1 - with cartridge, item - 2 - VAS 6201/2.
- Insert tube VAS 6201/8 (item - 7 - ) in service coupling and open service coupling by screwing in handwheel. Hold hose upwards and screw in toggle of hand pump until leak detection additive starts to emerge from tube.
NOTE: Make sure hand pump hose is completely filled with refrigerant.
- Close service coupling and remove tube from locking mechanism.
- Cover area around service connection on vehicle with sheeting or absorbent paper.
- Connect filler unit to refrigerant circuit service connection on vehicle.
- Open service connection by screwing in handwheel.
- Screw in toggle of hand pump to transfer 2.5 + /- 0.5 ml (milliliter= cu.cm) of leak detection additive to refrigerant circuit.
- Disconnect filler unit from service connection.
- Use absorbent paper, for example, to remove remnants of leak detection additive from service connection.
- Seal service connection with cap.
- If necessary, use cleaning agent to clean area around service connection.
- Affix sticker next to service connections to indicate that leak detection fluid has been added to the refrigerant circuit.
Refrigerant Circuit, Locating Leaks with UV Lamp VAS 6196/4
CAUTION:
- Never look into UV lamp.
- Never point UV lamp at other people.
NOTE:
- After filling, the air conditioner must be operated for at least 60 min. to distribute the additive throughout the refrigerant circuit compressor must run/be actuated).
- Depending on the magnitude and location, it may take several days for sufficient refrigerant oil and additive to emerge to clearly identify the leak.
- In the event of leaks at the evaporator, the additive may be washed out with the condensate and emerge via the condensate drain. As on most vehicles the evaporator is not accessible without considerable effort, checking the condensate drain for example can provide an indication of evaporator leakage. This does however require the additive to have been in the refrigerant circuit for a lengthy period (several days).
- The safety goggles are not only designed to provide eye protection. They also make the additive more readily visible under UV light.
- Depending on the accessibility of various parts of the refrigerant circuit, it may be necessary to remove certain vehicle components (e.g. bumper or air cleaner).
- Move vehicle to a less brightly lit area of the workshop (daylight or bright artificial lighting diminishes the effect of the UV light).
- Check accessibility of various parts of the refrigerant circuit and remove components in area of refrigerant circuit which would block view of refrigerant circuit components (e.g. noise insulation and bumper).
- Wear safety goggles to protect eyes.
- Connect UV lamp to a 12V battery (vehicle battery). Take care to ensure correct polarity of connections.
- Switch on UV lamp and illuminate components of refrigerant circuit. Locations at which leakage has resulted in the emergence of refrigerant, refrigerant oil and thus also leak detection additive show up under UV light (fluorescent).