Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 1659

1-22  HEATING AND AIR CONDITIONING

•

Direct charging with a manifold gauge charging

station method.

Handling the charge valve handle when installing refrigerant

container.

1) Before attaching the charge valve to the refrigerant

container, turn the charge valve handle counterclockwise

until the needle is fully retracted.

2) Turn the plate nut counterclockwise until it reaches its

highest position relative to the charge valve.

3) Install the charge valve onto the refrigerant container.

4) Turn the plate nut clockwise and connect the center hose of

the manifold gauge to the charge valve.

5) Tighten the plate nut sufficiently by hand. Then turn the

charge valve handle clockwise to lower the needle and bore

a hole in the refrigerant container.

6) Turn the charge valve handle counterclockwise to raise the

needle.  The refrigerant in the refrigerant container is

charged into the air conditioning system by the operation of

the manifold gauge.

•

Be absolutely sure not to reuse the emptied refrigerant

container.

HEATING AND AIR CONDITIONING  1-23

1) Make sure the evacuation process is correctly completed.

2) Connect the center-hose of the manifold gauge to the

refrigerant container.

•

Turn the charge valve handle counterclockwise to purge

to charging line and purge any air exiting in the center-

hose of the manifold gauge.

3) Open the low-pressure hand valve and charge the

refrigerant about 200 g (0.44 lbs.).

•

Make sure the high-pressure hand valve is closed.

•

Avoid charging the refrigerant by turning the refrigerant

container upside down.

4) Close the low-pressure hand valve of the manifold gauge.

•

Check to ensure that the degree of pressure does not

change.

5) Check the refrigerant leaks by using a R-134a leak

detector.

•

If a leak occurs, repair the leak connection, and start all

over again from the first step of evacuation.

6) If no leaks are found, open the low-pressure hand valve of

the manifold gauge. Then continue charging refrigerant to

the system.

•

When charging the system becomes difficult:

(1) Run the engine at 1,300

∼

1,500 rpm and open the all

vehicle doors.

(2) A/C switch is "ON".

(3) Set the fan control knob (fan switch) to its highest

position.

WARNING
BE ABSOLUTELY SURE NOT TO OPEN THE HIGH-

PRESSURE HAND VALVE.  SHOULD THE HIGH-

PRESSURE HAND VALVE BE OPENED, THE HIGH-

PRESSURE REFRIGERANT GAS WOULD FLOW

BACKWARD, AND THIS MAY CAUSE THE REFRIGERANT

CONTAINER TO BURST.

7) When the refrigerant container is emptied, use the following

procedure to replace it with a new refrigerant container.

(1) Close the low-pressure hand valve.

(2) Raise the needle upward and remove the charge valve.

(3) Reinstall the charge valve to the new refrigerant

container.

(4) Purge any air existing in the center hose of the manifold

gauge.

8) Charge the system to the specified amount and then close

the low-pressure hand valve.

Refrigerant Specified Amount

g(lbs.)

650 (1.43)

1-24  HEATING AND AIR CONDITIONING

•

A fully charged system is indicated by the sight glass on

the receiver/drier being free of any bubbles (Refer to

"Reading Sight Glass").

•

Check the high and low pressure value of the manifold

gauge.

•

Check for refrigerant leaks by using a R-134a leak

detector.

Immediately after charging refrigerant, both high and low

pressures are slightly high and to the left of the gauge, but they

settle down to the guide pressure valves as shown below:

•

Ambient temperature; 30

∼

35

°

C (86

∼

95

°

F)

•

Guide pressure

High-pressure side;

Approx. 1373

∼

167 kPa (14

∼

17 kg

⋅

cm

2

/199

∼

242 PSI)

Low-pressure side;

Approx. 127

∼

245 kPa (1.3

∼

2.5 kg

⋅

cm

2

/18

∼

36 PSI)

9) Close the low pressure hand valve and charge valve of the

refrigerant container.

10)Stop the air conditioning and the engine.

11)Disconnect the high and low pressure hoses from the

manifold gauge fittings.

HEATING AND AIR CONDITIONING  1-25

Reading Sight Glass

High and low
pressure pipe
temperature

The high pressure
pipe is hot and the
low pressure pipe is
cold.  There is a
distinct difference
in temperature
between them.

The high pressure
pipe is warm and
the low pressure
pipe is cool.  There
is no great
difference in
temperature
between them.

There is little
difference in
temperature
between the high
pressure pipe and
the low pressure
pipe.

The high pressure
pipe is hot and the
low pressure pipe is
slightly warm.
There is a
difference in
temperature
between them.

Sight glass
condition

Almost transparent.
A flow of bubbles
can be seen, but
they disappear
when the throttle is
opened.

A flow of bubbles
always can be
seen.  It appears
sometimes
transparent, and
sometimes frothy.

Something like fog
faintly can be seen.

Evan at idle with
the fan at "HI" (with
the window fully
open), the bubbles
cannot be seen.

Air conditioning
cycle condition

OK

NG

(Not enough

refrigerant)

NG

(Almost no

refrigerant)

NG

(Too much

refrigerant)

The sight glass provides accurate diagnosis only under the following conditions.

If the vehicle can be tested under these conditions, check the sight glass appearance and compare to the chart

*

Engine speed 1,500 RPM

*

A/C switch "ON"

*

Blower fan operating at highest speed

*

Air source selector lever at "RECIRC"

*

Temperature control lever at coldest position

*

Ambient temperature below 35

°

C (95

°

F) and humidity below 70% (See NOTE 1)

*

High side pressure less than 1667 kPa (17 kg

⋅

cm

2

/242 PSI) (See NOTE 2)

NOTE 1
If the vehicle cannot be moved to a testing location that meets these specifications, then the sight glass cannot be

used for diagnosis.  You must discharge and recover the refrigerant, then recharge the system with the specified

amount of refrigerant.

Then continue checking the system performance.

NOTE 2
If the high side pressure is greater than stated, the sight glass cannot be used for diagnosis.  You must discharge

and recover the refrigerant, then recharge the system with the specified amount of refrigerant.

Then continue checking system performance.