Great Wall Hover. Manual - part 90

CD Player and Air Conditioning System-14

Pumping Out of A i r Conditioning System to the Vacuum and Addition of Refrigeration Oil

Connect the manifold pressure gauge with the pipe of air conditioner (compressor) and the multi-purpose adapter of the vacuum

pump for the purpose of pumping out of the system to the vacuum state.

Before pumping out to the vacuum, turn on the high-pressure and low-pressure valve of the manifold pressure gauge and the end valve

(if provided) of the vacuum pump, then press the button ON to start the vacuum pump, the duration shall be more than 20 minutes.

When the reading of manifold pressure gauge is -760mmHg or below, turn off the high-pressure and low-pressure valve (if opened),

and press the switch to turn off the vacuum pump

1. check the air tightness

Continue to check the pressure reading of the manifold pressure gauge after turning off the vacuum pump.

If the pressure reading remains unchanged within 20 minutes after the vacuum pump stops running, then it indicates that th e

refrigerating system has no leakage, the operator can proceed with next work; while change of the reading indicates that the

system has the leakage. Launch the examination and pump out to the vacuum after the leakage is fixed.

2. Injection of the refrigerant

When the air tightness of the system is verified correct, connect the refrigerant reservoir (or gas bottle) with one end of the yellow

air-charging hose, while other end of yellow air-charging hose is connected with the liquid injection port in the middle of the

manifold pressure gauge. Ensure that the refrigerant reservoir is connected firmly with the nut of air-charging hose, then turn on
the valve of refrigerant reservoir; at this time, the high-pressure and low-pressure is closed, use a tip screw driver or other similar
tools and press the by-pass valve spool for 1~ 2 seconds to discharge out the air in the air-charging hose and the manifold
pressure gauge.

low pressure

high pressure

manifold pressure gauge

quick coupler

low-pressure pump

high-pressure pipe

quick coupler

quick

coupler

red

blue

vacuum pump

manifold pressure gauge

low pressure gauge

high pressure gauge

Red

blue

yellow

4. Attention:

a. when a new compressor is used to substitute for the old one, the oil must be released to some extent that its oil volume is the

same as that of old compressor so as to avoid the influence over the refrigeration effect due to too much oil.

b. when an old or repaired compressor is employed, the volume of the refrigeration oil in the compressor must be kept the same

as that of the replaced compressor.

CD Player and Air Conditioning System-15

Turn on the high-pressure valve on the manifold pressure gauge and inject the refrigerant to the system from high-pressure pipeline.

At this time, the attention shall be given to the readings of high-pressure meter and low-pressure meter, and make sure that these two

pressure all go up. If the refrigerant is being injected while the pressure does not go up, then the joints of the pipeline may be loosened

or the seals damaged, inject the refrigerant once more after finding out the cause and the fixing. When the increase of pressure stops,

turn off the high-pressure valve of the manifold pressure gauge and then start the engine

Operate the switch in a way as follows:

Turn the switch of air conditioner to “ON”

Regulate the temperature controller to the coolest position,

Enable the air conveying to the maximum,

Select the internal air circulation between the internal/external air circulation,

During this process, the door and windows will be all opened.

Adjust the engine’s speed to the specified free running speed.

Erect the refrigerant reservoir or gas bottle (have the refrigerant injected into the refrigerating system in a gas state), turn on the

low-pressure valve of the manifold pressure gauge.

When the compressor is at work, please do not turn on the high-pressure valve.

Before checking the refrigeration level, please confirm the injection volume of the refrigerant specified for air conditioning system.

When injecting the refrigerant, carefully observe the high-pressure side of the manifold pressure gauge and the flow condition of

the refrigerant (clear, foaming or turbid), all these could be viewed through the inspection window, by which the moment of stop

injecting the refrigerant can be reasonably judged(turning off the low-pressure valve).

air washing

off

tip screw driver

red

yellow

blue

refrigerant reservoir

high-pressure

low-pressure

off

low-pressure pipe

high-pressure pipe

refrigerant reservoir

yellow

red

blue

CD Player and Air Conditioning System-16

refrigerant reservoir

high-pressure pipe

low pressure

high pressure

yellow

red

blue

low-pressure pipe

When judging the injection volume of the refrigerant, please make the settings based on the following working conditions:

Water tank temperature of the engine: stable

Speed of the engine: normal free running speed

Switch of air conditioner: ON

Switch of the fan: “High” gear

Temperature controller: air return temperature inside the car is between 25

and 30

Fresh air control: internal circulation

Door: all opened

Window: all opened

Repair and replacement of pipeline

a. Before installation of parts and components, the negative pole of the accumulator must be disconnected.

cut off

b. When the air entries of the refrigerating system, water tank of the engine and the air conditioner are opened, please make sure that

all openings are capped to prevent the penetration of the dust, foreign matters or water.

rotective cap protective cap

protective cap must be installed.

CD Player and Air Conditioning System-17

Daily Maintenance of Air Conditioning System

In order to ensure normal operation of air conditioning system, maintenance and care services shall be frequently performed for the

air conditioning system. The daily maintenance of air conditioning system is illustrated as follows:

1. Inspect, wash and clean the condenser of air conditioning system, requiring that radiator pins are clean and there is no dirt

between the pins. After the car runs in the rain or on the muddy road, the fan of the condenser should be inspected to find

whether it bears the earth, sand, stone and etc, and remove them if any.

2. Check the quantity of the working media of the refrigerating system; when the compressor set works normally, observe the

liquid viewing glass, under the normal circumstance, there shall be not air bubbles in the glass.

3. Inspect the drive belt. The belt between the compressor and the engine should be tensioned.

4. Check if there is any abnormal noise or odor in the air conditioning system.

5. Check if the temperature difference between the air inlet and outlet of the compressor is normal.

6. Check if the hose of the refrigerating system is in an apparent good condition and connections of all joints are secure.

7. Check if the pipeline of the refrigerating system collides with other parts and components, and if there is any oil leakage trace

left at each joint.

8. Check if the circuit connection of the refrigerating system is secure and if there is an occurrence of short circuit and falling off

9. Check if fastening bolts of the compressor are firmly secured or broken.

d. When connecting the pipe, apply little compressor oil to the O-ring and fasten the nut with two wrenches. Attention: never

spatter the compressor oil to the painted parts or the plastic components to avoid the corrosion. If these components are

spattered with the oil, please clean it immediately.

e. When connecting the pipe, please follow the torque listed in the following table to fasten the screws or the nuts:

Diameter of Pipe

Fastening Torque (N·m)

￠8mm 12-15

￠16mm 30-35

30－35

At ends of each pipe the protective caps should be installed till the pipe is connected to the refrigerating system.

compressor oil fasten it by using two wrenches at the same time

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