Air conditioning system has gradually become the standard equipment of cars. There are many kinds of air conditioners used in automobiles, and their structures are similar. The maintenance interval shall be generally once a year or as required. If it is found that the refrigeration effect is not good in use, it should be checked. The fault is usually caused by refrigerant leakage. Inspection and repair can be carried out through the following steps.

1.查找泄漏部位

1. Find the leakage part

目前车辆上使用的空调系统一般为单冷开启式，制冷剂多采用氟里昂（R12或氟里昂的替代产品134a）。在使用中，制冷剂易从各连接接头、油封处泄漏，制冷剂泄漏将会导致制冷效果差或不制冷等现象。

At present, the air conditioning system used in vehicles is generally single cold open type, and the refrigerant is mostly Freon (R12 or alternative product 134a of Freon). In use, the refrigerant is easy to leak from the connection joints and oil seals, which will lead to poor refrigeration effect or no refrigeration.

（1）检查漏油痕迹。在空调制冷循环系统中，冷却油是用来润滑密封轴承以及压缩机内其他运动部件的，少量的润滑油将会与制冷剂一起进入制冷循环系统中。如果制冷循环系统发生泄漏，泄漏处就会出现油渍，所以在检查中，发现管路及接头处有油渍，就可以确定该处有泄漏故障，应进行修理。

(1) Check for traces of oil leakage. In the air conditioning refrigeration cycle system, the cooling oil is used to lubricate the sealed bearing and other moving parts in the compressor. A small amount of lubricating oil will enter the refrigeration cycle system together with the refrigerant. If the refrigeration cycle system leaks, there will be oil stains at the leakage. Therefore, if there are oil stains on the pipelines and joints during the inspection, it can be determined that there is a leakage fault at this place, which should be repaired.

（2）观察检视窗，判定制冷剂泄漏情况。起动发动机（约1000r/min），打开制冷控制开关（A/C），将温度开关控制杆置于COLD（冷）位置，风扇开关开到的位置，可以从检查窗处观察到制冷剂的流动状态，来判断制冷循环系统中有无泄漏。

(2) Observe the inspection window to determine the leakage of refrigerant. Start the engine (about 1000r / min), turn on the refrigeration control switch (A / C), set the temperature switch control lever to the cold position, and turn on the fan switch to the maximum position. The flow state of refrigerant can be observed from the inspection window to judge whether there is leakage in the refrigeration cycle system.

制冷剂流动正常：制冷剂大体上透明，此时出风口的风是冷的。制冷系统的状态正常。

The refrigerant flow is normal: the refrigerant is generally transparent, and the air at the air outlet is cold. The state of the refrigeration system is normal.

制冷剂不足：制冷剂不足时，就会经常看到气泡流动，制冷剂呈乳白色，这时制冷效果不佳。

Insufficient refrigerant: when the refrigerant is insufficient, bubbles will often be seen flowing, and the refrigerant is milky white, and the refrigeration effect is poor.

没有制冷剂：如果制冷系统严重泄漏，观察玻璃窗内就什么也看不到，此时空调系统不会制冷。富康轿车的储液罐上有A、B两个检视窗。检视窗A可以判断储液罐中干燥剂的水分含量是否饱和。若呈蓝色，表示正常；若呈红色，表示水分已呈饱和状态。应缓慢的排尽空调系统中的制冷剂，更换储液罐中的干燥剂，然后重新加注制冷剂。B检视窗的作用和前面介绍的内容相同，主要用于观察制冷剂的情况。

No refrigerant: if the refrigeration system leaks seriously, nothing can be seen in the observation glass window. At this time, the air conditioning system will not cool. There are two inspection windows a and B on the tank of Fukang car. Inspection window a can judge whether the moisture content of the desiccant in the reservoir is saturated. If it is blue, it means normal; if it is red, it means that the water is saturated. The refrigerant in the air conditioning system should be drained slowly, the desiccant in the reservoir should be replaced, and then the refrigerant should be refilled. The function of the B inspection window is the same as that described above. It is mainly used to observe the condition of refrigerant.

在检查时，所有连接部位或冷凝器表面一旦发现油渍，一般都说明此处有制冷剂泄漏。发现有泄漏现象时，应及时进行排除泄漏故障，补充制冷剂和润滑油，以防泄漏润滑油，损坏空调系统。

In the inspection, once oil stains are found on all connection parts or condenser surface, it generally indicates that there is refrigerant leakage here. In case of leakage, the leakage fault shall be eliminated in time, and the refrigerant and lubricating oil shall be supplemented to prevent the leakage of lubricating oil and damage to the air conditioning system.

2.检查空调系统的工作情况

2. Check the working condition of air conditioning system

检查时将汽车停放在通风良好的场地上，保持发动机中等转速，将空调机风速开到挡，使车内空气内循环。

During the inspection, park the car in a well ventilated place, keep the engine at medium speed, turn the air conditioner to the maximum speed, and circulate the air inside the car.

（1）从各部的温度判断空调状态。用手触摸空调系统及各部件，检查表面温度。正常情况下，低压管路呈低温状态，高压管路呈高温状态。

(1) Judge the air conditioning state from the temperature of each part. Touch the air conditioning system and its components by hand to check the surface temperature. Under normal conditions, the low-pressure pipeline is in a low-temperature state, and the high-pressure pipeline is in a high-temperature state.

高压管路：压缩机出口→冷凝器→储液罐→膨胀阀进口处。这些部件应该先暖后热，手摸时应特别小心，避免被烫伤。如果在其中某一点发现有特别热的部位，则说明此处有问题，散热不好。如果某一点特别凉或结霜，也说明此处有问题，可能有堵塞。干燥储液器进出口之间若有明显温差，说明此处有堵塞。

High pressure pipeline: compressor outlet → condenser → liquid storage tank → inlet of expansion valve. These parts should be warmed first and then heated. Special care should be taken when touching them to avoid scalding. If a particularly hot part is found at one point, there is a problem here and the heat dissipation is not good. If a certain point is particularly cold or frosty, it also indicates that there is a problem here and there may be blockage. If there is obvious temperature difference between the inlet and outlet of the drying reservoir, it indicates that there is blockage here.

低压管路：膨胀阀出口→蒸发器→压缩机进口，这些表面应该由凉到冷，但膨胀阀处不应发生霜冻现象。

Low pressure pipeline: expansion valve outlet → evaporator → compressor inlet, these surfaces should be from cold to cold, but frost should not occur at the expansion valve.

压缩机高低侧之间应该有明显的温差，若没有明显温差，则说明空调系统内没有制冷剂，系统有明显的泄漏。

There should be obvious temperature difference between the high and low sides of the compressor. If there is no obvious temperature difference, it means that there is no refrigerant in the air conditioning system and there is obvious leakage in the system.

（2）清理空调装置上的杂物。检查蒸发器通道及冷凝器表面，以及冷凝器与发动机水箱之间（停机检查）是否有杂物、污泥，要注意清理，仔细清洗。冷凝器可用毛刷轻轻刷洗，注意不能用蒸气冲洗。

(2) Clean the sundries on the air conditioner. Check the evaporator channel and condenser surface, as well as between the condenser and the engine water tank (shutdown inspection) for debris and sludge. Pay attention to cleaning and cleaning carefully. The condenser can be gently brushed with a brush, and it should not be washed with steam.

（3）检查调整空调皮带。检查皮带松紧度是否适宜、表面是否完好（与发动机皮带检查调整相同）。以上检查如果发现异常时，应进行修理。

(3) Check and adjust the air conditioning belt. Check whether the belt tightness is appropriate and whether the surface is intact (the same as the engine belt inspection and adjustment). If any abnormality is found in the above inspection, it shall be repaired.