7B
Quickly Checking of Refrigerant Charge
M13 Engine Model
There is not sight grass in M13 engine model.
Regarding the refrigerant charge, refer to “Charging of A/C System” in Operation Procedure for Refrigerant Charging .
K9K Engine Model
Charge of Refrigerant
The following procedure can be used for quickly checking whether the A/C system has a proper charge of refrigerant or not. Run engine at fast idle, and operate A/C at its maximum cooling capacity for a few minutes. Then, look at the sight glass (1) on receiver/dryer (2) and compare what is observed with the symptoms listed in below.
3. Bubbles
Checking Refrigerant Charge
Item No. Symptom Charge of refrigerant Correction
1 Bubbles observed in sight glass Insufficient charge of refrigerant in system Check system for leaks with a leak tester.
2 No bubbles observed in sight glass No or insufficient charge of refrigerant in system Refer to the items 3 and 4.
3 No temperature difference between compressor inlet and outlet Empty or nearly empty system Evacuate and charge system and then check it for leaks with a leak tester.
4 Noticeable temperature difference between compressor inlet and outlet Proper or too much charge of refrigerant in system Refer to the items 5 and 6.
5 When A/C is turned OFF, refrigerant in sight glass clears immediately and remains clear Too much charge of refrigerant in system Discharge excess refrigerant in order to obtain a specified charge.
6 When A/C is turned OFF, refrigerant in sight glass once produces bubbles and then clears Proper charge of refrigerant in system No correction needed because charge of refrigerant is normal.