Checking Air Conditioning
Information
Leaking air-conditioning systems must only be filled with nitrogen or forming gas for the purposes of leak testing.
Leak detector additives must only be used if there is no clear indication from the leak test using nitrogen or forming gas.
Leak detector additives from Waeco are compressor oils with fluorescent components and meet the requirements for the operational fluids and fuels.
Only compressor oils with fluorescent components may be used as leak detector additives.
Leak detector additive: Tracer UV additive (500 ml container) TP-3525-500 specifically for Waeco air conditioning service equipment.
Leak detector additive: Tracer UV additive (stick) TP-9825-0301; can be used universally for all air conditioning service equipment.
Special adapter kits are required for filling the Tracer UV additive (stick) TP-9825-0301 and Traserline TP 3860; these are also available from air conditioning service equipment providers (e.g. Waeco).
Fluorinated greenhouse gases are not permitted in leak testing.
Instructions for use and the procedure for filling the air-conditioning system can be found in the operating instructions provided by the respective air conditioning service equipment provider.
Information
The troubleshooting steps shown must be used if complaints are received about the cooling output of the air-conditioning system.
| Condition | Specification OK | Specification not OK |
|---|---|---|
| 1) Check the cooling output, temperature and air flow. Check the air distribution by making adjustments on the air-conditioning control panel. Start the vehicle and check the air-conditioning system for the prescribed nominal temperature values. > 8X00IN - NOMINAL VALUES FOR PRESSURES AND TEMPERATURES |
Specified air flow and temperature is reached. Air distribution is working. Continue with Step 2) . |
Insufficient air flow from the air vents. Continue with Step 3. Required temperature is not reached. Continue with Step 2). |
| 2) Perform on-board diagnosis on all control units using the PIWIS Tester. | No fault memory stored, air flow and temperature complies with specified nominal values. Function OK. No further action required. No fault memory stored and the temperature does not reach the specified nominal values. Continue with Step 4. |
Fault present: Work through the fault memory in accordance with Guided Fault Finding instructions. Continue with Step 1). |
| Check the following points one after the other. Replace if necessary. Remove particle filter and check for dirt and dust particles. > 851819 - REMOVING AND INSTALLING PARTICLE FILTER Check fan motor for correct operation and control. Use wiring diagram for this. Check the mechanical operation of the servo motors/flaps using the PIWIS Tester. |
Fan motor OK. Particle filter OK. Servo motors/flaps OK. Continue with Step 4). |
Replace particle filter. > 851819 - REMOVING AND INSTALLING PARTICLE FILTER Replace fan motor. > 853019 - REMOVING AND INSTALLING FAN MOTOR Replace servo motor. Example: > 872019 - REMOVING AND INSTALLING SERVO MOTOR FOR DEFROSTER If the servo motor flap is faulty, replace heating/fresh-air unit. > 851519 - REMOVING AND INSTALLING HEATING/FRESH-AIR UNIT (COMPLETE) If the servo motor flap is faulty, replace heating/fresh-air unit. Following repairs, continue with Step 1). |
| 4)
Connect air conditioning service equipment, measure high and low pressure and compare with nominal values. > 8X00IN - NOMINAL VALUES FOR PRESSURES AND TEMPERATURES |
High and low pressure OK. Function OK. No further action required. |
High pressure too high. Continue with Step 5). High pressure too low. Continue with Step 6). Low pressure too high. Continue with Step 7). Low pressure too low. Continue with Step 8). |
| 5)
High pressure too high. Check the following points one after the other: Check the condenser for dirt/dust particles and damage. Check electrical operation, condenser fan activation. Drain refrigerant and measure and document the amount of refrigerant removed. >> Too much refrigerant. > 870317 - DRAINING AND FILLING REFRIGERANT R1234YF |
Clean the condenser. Repair electric fan activation mechanism. Use wiring diagram. Fill the air-conditioning system with the prescribed amount of refrigerant. > 8X00IN - TECHNICAL DATA FOR AIR-CONDITIONING SYSTEM WITH COOLANT R1234YF Continue with Step 1). |
|
| 6) High pressure too low. Check the following points one after the other: Check electrical operation, air-conditioning compressor activation. Drain refrigerant, measure and document the amount of refrigerant. |
If the amount of refrigerant is correct, remove the expansion valve and check for foreign bodies (e.g. chips, abrasion). > 877019 - REMOVING AND INSTALLING EXPANSION VALVE Replace expansion valve if necessary. Continue with Step 1) |
Repair air-conditioning compressor activation mechanism. Use wiring diagram. If there is not enough refrigerant, fill the air-conditioning system according to specifications. > 8X00IN - TECHNICAL DATA FOR AIR-CONDITIONING SYSTEM WITH COOLANT R1234YF Check refrigerant circuit and connection points using a leak detector. >> Once you have determined the cause of refrigerant loss, replace seal or spare part. Continue with Step 1) |
| 7) Low pressure too high. Check the following points one after the other: Drain refrigerant and measure and document the amount of refrigerant. Too much refrigerant. > 870317 - DRAINING AND FILLING REFRIGERANT R1234YF |
If the amount of refrigerant is correct, remove the expansion valve and check for foreign bodies (e.g. chips, abrasion). > 877019 - REMOVING AND INSTALLING EXPANSION VALVE Replace expansion valve if necessary. Continue with Step 1) |
If there is too much refrigerant, fill the air-conditioning system according to specifications. > 8X00IN - TECHNICAL DATA FOR AIR-CONDITIONING SYSTEM WITH COOLANT R1234YF Continue with Step 1) |
| 8) Low pressure too low. Check the following points one after the other: Drain refrigerant and measure the amount of refrigerant. Not enough refrigerant. > 870317 - DRAINING AND FILLING REFRIGERANT R1234YF Loosen lines on the air-conditioning compressor and check for foreign bodies (e.g. chips, abrasion). > 873419 - REMOVING AND INSTALLING AIR-CONDITIONING COMPRESSOR |
If the amount of refrigerant is correct, remove the expansion valve and check for foreign bodies (e.g. chips, abrasion). > 877019 - REMOVING AND INSTALLING EXPANSION VALVE Replace expansion valve if necessary. Continue with Step 1) |
Fill the air-conditioning system with the prescribed amount of refrigerant. > 8X00IN - TECHNICAL DATA FOR AIR-CONDITIONING SYSTEM WITH COOLANT R1234YF Check refrigerant circuit and connection points using a leak detector. >> Once you have determined the cause of refrigerant loss, replace seal or spare part. Replace air-conditioning compressor if necessary. Continue with Step 1) |