SANY Crawler Hydraulic Excavator SY365H-9, SY365BH-9. Shop Manual (2014)

4-146

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

●

Refrigerant cycle principle (pressure - enthalpy diagram)

ZX215-1002152

Gas-liquid mixture

lgp

h=u+Apv(kJ/kg)

Internal energy

Pressure

Special volume

Joule equivalent

Expansion throttle

Condensing process

Evaporating process

Compressing
process

Throttling point

Gasification completed

Liquefaction starts

Liquefaction completed

Expansion valve

Liquid

Evaporator

Compressor

Condensor

Refrigerant cyclic curve

Fig. 4-141

4-147

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002153

ZX215-1002154

Proper filling

Inadequate filling

Sight glass

3. Feeding of refrigerant

●

Filling method and volume:

1) Refrigerant: HFC-134a

2) Feeding volume: 900

50 g (for refer-

ence)

3) Feeding method: Feeding of liquid re-

frigerant from the low-pressure end is
not allowed. If feeding operation fails,
discharge the refrigerant that has been
fed before re-feeding.

●

Inspect the state of the refrigerant in the
A/C circulation system through the sight
glass:

1) Correct feeding: Foam is hardly ob-

served when the refrigerant is

owing.

When engine speed increases from
idling to 1500 rpm, foam disappears
and the refrigerant turns clear.

2) Over-feeding: No foam can be ob-

served when refrigerant is

owing.

3) Under-feeding: Foam is always ob-

served when refrigerant is

owing.

4. Evacuation

●

Reason of evacuation

No moisture shall be mixed inside the air
conditioning unit. Refrigerant (R134a) is
soluble in water. Very small amount of
moisture in the unit can cause the ori

ce of

the expansion valve to ice up, or cause the
valve of the compressor to rust. To avoid
such problems, moisture in the system
shall be removed before refrigerant is fed.
To reduce the residual moisture in the sys-
tem to the minimum, moisture in the sys-
tem can evaporate through evacuating. No
better means is available so far.

Fig. 4-142

Fig. 4-143

4-148

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002155

Lo-pres. valve (ON)

Hi-pres. valve(ON)

Lo-pres.
gauge

Lo-pres.gauge

Hi-pres. gauge

Blue

Red

Green

above 750mmHg

Vacuum pump (running)

Compressor

Valve

ON ON

OFFOFF

●

Evacuating steps

1) Connection of manifold pressure

gauge:

a) Close the high-pressure valve (HI)

and low-pressure valve (LO) of the
manifold pressure gauge.

b) Connect the air hose (red, blue)

t o t h e a u x i l i a r y v a l v e o f t h e
compressor.

Red hose

——

High pressure side

(Mark D)

Blue hose

——

Low pressure side

(Mark S)

★

Connect the end of the air hose
with a L to the auxiliary valve of the
compressor. If connected inverse-
ly, the valve will not open. Besides,
do not inversely connect the high-
pressure end and the low-pressure
end.

c) Connect the middle hose (green) to

the vacuum pump.

2) Evacuating

a) Open the high-pressure valve (HI)

and low-pressure valve (LO) on the
manifold pressure gauge.

b) Turn on the vacuum pump and

evacuate for about 15 minutes.

c) When negative pressure reading

on the gauge (degree of vacuum)
reaches above 750 mmHg, turn off
the vacuum pump and close the Hi-
pressure valve and the Lo-pressure
valve on the gauge.

Fig. 4-144

4-149

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002157

R134a

OFFOFF

Vent valve

Release air

Blue

Red

Air hose (green)

To compressor

Fluorine cylinder

Open the valve

Valve

ZX215-1002158

R134a

Fluorine cylinder

Compressor

Open Hi-pres.valve

Lo-pres.valve (OFF)

Cylinder valve (ON)

Lo-pres. gauge
reads

1kg/cm

Lo-pres. gauge
reads

1kg

Lo Hi

1kg/cm

Valve

OFF

OFFOFF

3) Air - proof check

a) Keep the Hi- and Lo-pressure valve

of the manifold pressure gauge
under closed state for more than 5
minutes, and make sure the pointer
on the gauge does not return to
zero.

b) If the pointer returns to near zero,

a leakage is available somewhere.
Check and adjust the pipe joint.
Tighten the joint and conduct an-
other evacuating operation until no
leakage is detected.

4) Leak check

a) Connect the air hose (green) that is

previously connected to the vacuum
pump to the

uorine cylinder.

b) Connect the other end of the hose

(green) to the pressure gauge.
Open the valve of the cylinder and
press the vent valve of the pres-
sure gauge. (Do not press the valve
with naked hand to avoid frostbite
caused by refrigerant). Release the
air in the hose with the pressure of
the refrigerant. (Release the vent
valve when you hear a squeezing
sound).

c) Add refrigerant until pressure read-

ing on the Lo-pressure gauge is
1kgf/cm

. Hi-pressure valve of the

gauge is open at this time. Close
the Hi-pressure valve when feeding
is

nished.

d) Use a leak detector to check if

leakage is present in the cooling
system.

e) Make necessary repairs (tightening)

if leakage is observed.

ZX215-1002156

Tighten the connector

Lo-press gauge
backs to zero.

Left at least
for 5 minutes

Lo-press gauge

Pointer backs
to zero.

Valve

OFFOFF

Lo Hi

Fig. 4-145

Fig. 4-146

Fig. 4-147

4-150

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

Wait 5 min

More than 15 min.

Tighten pipe joint

Pres. gauge

abnormal

Pres. gauge

normal

Repair any leak.

75cm-Hg or more

(1) Compressor stopped, fill at hi pressure end

(2)Compressor running, add at lo pressure end

Evacuation starts

Evacuation ends

Air-proofness check

Fill refrigerant kg/cm

Air leak check

Fill refrigerant

Air leak check

Performance testing

ZX215-1002159

Lo Hi

R134a

Loosen
this nut

OFFOFF

Vent valve

Blue

Red

Air hose (green)

To compressor

Fluorine cylinder

Open the valve

(Note)
Refrigerant is released
when squeaking is heard.

Valve

5. Refrigerant

lling operation

●

When evacuation is

nished,

ll refrigerant

into the cooling system as per the following
instruction:

●

Fill from the hi-pressure side

1) Remove the air hose (green) of the

manifold pressure gauge from the vac-
uum pump and connect it to the

uorine

cylinder.

2) Open the valve of the cylinder and

press the vent valve on the pressure
gauge. Use the pressure of the refriger-
ant to release the air in the hose.

Release the vent valve when you hear

a squeezing sound. Do not press the
vent valve with naked hand to avoid
frostbite.

Fig. 4-148

4-151

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

3) With the engine stopped, open the

high-pressure valve on the manifold
pressure gauge and the fluorine cylin-
der valve and

ll in one and a half cylin-

der of

uorine (approximate 600g).

Do not run the compressor at this

moment. Once the compressor is
started, the refrigerant could flow
back, causing the fluorine cylinder
and hose to burst.

Operating the compressor without

refrigerant will burn the compressor.
Never run the compressor without
refrigerant.

Do not open the low-pressure valve

on the manifold pressure gauge (liq-
uid compression will occur, causing
damage tot he compressor).

4) Close the high-pressure valve on mani-

fold pressure gauge and the fluorine
cylinder valve.

ZX215-1002160

R134a

Lo Hi

(Never)
·Run the compressor
·Open the low-press valve

Valve

OFF

Lo press valve (OFF)

Fluorine cylinder
valve (ON)

Filling one cylinder
(about 600g)

OFF OFF

Open the high-press valve

●

Fill from lo-pressure side (additional

ll-

ing)

1) Confirm the hi-pressure valve of the

manifold pressure gauge is closed.

2) Start the engine and open the cab door.

3) Turn on the air conditioner, and set

Temperature control switch to mini-
mum.

4) Adjust engine speed to 1300 – 1500

rpm.

5) Open the Lo-pressure valve of the

manifold pressure gauge and the valve
of the

uorine cylinder, and

ll refriger-

ant into the reservoir until no foam is
observed.

Fig. 4-149

Fig. 4-150

ZX215-1002161

Hi-press valve (OFF)

Manifold
Press gauge

(Note)
Opening the high-pressure valve
can cause the fluorine cylinder
to explode, resulting in serious
injury

Engine started

1300~1500rpm

H I

4-152

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002162

Fluorine cylinder
(never placed upside down)

Compressor
running

Hi-pressure valve (close)
(Never open it)

Lo-pressure
valve (open)

Fluorine cylinder
valve (open)

Lo-pressure gauge
(1.5~2.5kgf/cm

)

Lo Hi

Fill until no foam is not
observed via sight glass

Hi-pressure gauge
(13~17kgf/cm

)

ON OFF

OFFOFF

Valve

6) When refrigerant

lling is

nished, close

the Lo-pressure valve of the manifold
pressure gauge and the valve of the

uorine cylinder.

7) Check carefully for air leaks with a leak

detector.

Never open the Hi-pressure valve of

the manifold pressure gauge. If it is
opened, high-pressure gas will coun-
terflow and cause the air hoses and
the

uorine cylinder to explode, result-

ing in serious injury.

Do not position the fluorine cylinder

upside down (when engine is oper-
ating and filling in progress). If the
cylinder is placed upside down, liquid
refrigerant will be sucked directly into
the compressor and cause liquid com-
pression, resulting in damage to the
compressor valve and the gaskets.
Place the cylinder vertically and fill
gas refrigerant.

8) When ambient temperature is low

When refrigerant

lling can not be per-

formed due to low ambient tempera-
ture, place the cylinder in water of less
than 40

℃

to increase the pressure of

the refrigerant inside the cylinder.

9) When ambient temperature is high

When ambient temperature is very
high, cool the compressor with an elec-
trical fan.

Note:

Manifold pressure gauge reading (for refer-
ence):

High pressure

13~17kg/cm

(ambient tempera-

ture 30

℃

);

Low pressure

1.5~2kg/cm

(ambient tempera-

ture 30

℃

Fig. 4-151

Fig. 4-152

ZX215-1002163

Warm water less than 40°C
(Do not heat with hot water)

Compressor
running

Hi-pressure valve
(close)

Lo-pressure
valve (open)

Cylinder valve
(open)

ON OFF

Lo Hi

Fill until no foam is seen
via the sight glass

Valve

OFF OFF

4-153

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002164

Air hose port

Handle

Gasket

Needle
valve

Refrigerant
cylinder

Disc plate

ZX215-1002165

Loosen Close

R-134a

Blue

Red

Green

To compressor

Refrigerant cylinder

Loosen the valve a bit

Valve

Lo-pressure
valve

Close the Lo-pressure valve
immediately after the refrig-
erant squeaks.

●

Replace the

uorine cylinder

When the refrigerant in a cylinder is used
up, replace the cylinder as per the follow-
ing instruction:

1) Close the Hi- and Lo-pressure valves of

the manifold pressure gauge.

2) Raise the needle and disc plate of the

cylinder and remove the empty cylin-
der.

3) Install a new cylinder onto the cylinder

valve.

4) Release the air in the hose as per the

following instruction:

a) Tighten the valve of the

uorine cyl-

inder, and then, loosen it a bit.

b) Open the Lo-pressure valve of the

manifold pressure gauge a bit.

c) Press the vent valve and allow a lit-

tle refrigerant to come out. Immedi-
ately close the valve of the cylinder
and the Lo-pressure valve of the
manifold pressure gauge.

★

Do not press the vent valve with
naked hand to avoid frostbite by
refrigerant.

5) Turn the handle of the cylinder valve to

pierce the cylinder and continue filling
operation.

Fig. 4-153

Fig. 4-154

4-154

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002167

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

R134a

085

8.5

6. Troubleshooting with manifold pressure gauge

After the engine has been preheated, read the
pressure value on the gauge under the follow-
ing conditions:

1) Temperature at air inlet: 30 – 35

℃

2) Engine speed: 1500 rpm

3) Fan speed: High

4) Temperature control: Minimum.

5) Air mode: Recirculation

●

Refrigerating system under normal condi-
tion

Gauge reading:

Lo-pressure end 0.15~0.25 Mpa (1.5~2.5 Kg/
cm²)

Hi-pressure end 1.37~1.57 Mpa (14~16 Kg/
cm²)

Fig. 4-155

4-155

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

●

Moisture in the refrigerating system

Fault: Intermittent refrigeration to non-refriger-
ation

ZX215-1002168

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

Symptom

Cause

Analysis

Remedy

●

When the system is
operating, pressure
at the Lo-pressure
end unstable (some-
times vacuum,
sometimes normal)

●

Moisture in the system
ices up at the expan-
sion valve causing
temporary stop of
circulation. When ice
melts, the system be-
comes normal again.

●

Over-saturation of de-
hydrator.

●

Moisture in the system
ices up at the expan-
sion valve and hinders
the circulation of the
refrigerating system.

●

Replace receiver/
dehydrator

●

Remove the mois-
ture in the system
through constant
pumping.

●

Add proper volume
of new refrigerant.

Fig. 4-156

4-156

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

●

Insuf

cient refrigeration

Fault: Insuf

cient refrigeration.

ZX215-1002169

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

Symptom

Cause

Analysis

Remedy

●

Pressure at both Hi- and
Ho-pressure ends very
low

●

Foam is continuously ob-
served via the sight glass

●

Insuf

cient refrigeration.

●

Air leaks
somewhere
in the refrig-
erating sys-
tem

●

Insuf

cient re-

frigerant in the
system

●

Leak of refriger-
ant

●

Check for air leakage with a leak
detector. Make necessary re-
pairs.

●

Add proper amount of refriger-
ant.

●

When connected with the gauge,
if the reading is near zero, set
the system under vacuum state
after inspection and repair.

Fig. 4-157

4-157

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002170

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

●

Defective refrigerant circulation

Fault: insuf

cient refrigeration

Symptom

Cause

Analysis

Remedy

●

Pressure at both
Hi- and Lo-pressure
sides very low

●

Frosting on the pip-
ing between parts
and reservoir

●

Contaminant in the
reservoir hinders the

ow of refrigerant.

●

Blocked reservoir

●

Replace reservoir

Fig. 4-158

4-158

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002171

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

●

Refrigerant not circulating

Fault: Non-refrigeration (intermittent refrigera-
tion)

Symptom

Cause

Analysis

Remedy

●

Vacuum at Lo-pres-
sure side; pressure
at Hi-pressure side
extremely low

●

Frosting or conden-
sation on the pipes
around the expan-
sion valve or receiv-
er/dehydrator

●

Moisture or contami-
nant in the refrigerant
hinders the

ow of

refrigerant.

●

Air leak at the thermal
pipe of the expansion
valve hinders the

of refrigerant.

●

Refrigerant not
circulating

●

Check the expansion valve
and ERP.

●

Blow the contaminant in the
expansion valve or replace
the expansion valve if nec-
essary.

●

Replace the receiver

●

Release internal air and
add refrigerant. If air leaks
from thermal pipe, replace
expansion valve.

Fig. 4-159

4-159

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002172

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

●

Over-

lling of refrigerant or insuf

cient re-

frigeration of condenser

Fault: Insuf

cient refrigeration

Symptom

Cause

Analysis

Remedy

●

Pressure at both Hi-
and Lo-pressure
sides very high

●

No foam can be ob-
served via the sight
glass even when
engine speed drops.

●

Over-

lling of refriger-

ant in the system. Re-
frigerating performance
inadequate.

●

Insuf

cient refrigeration

of condenser

●

Excessive refrigerant in
system

→

Over-

lling of

refrigerant

●

Insuf

cient refrigeration

of condenser

→

Ra-

diator

ns of condenser

plugged or failure of fan
motor

●

Clean the condenser

●

Check the working
condition of fan mo-
tor

●

If the two above
items are normal,
check the volume of
refrigerant. Add re-
frigerant as required.

Fig. 4-160

4-160

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002173

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

●

Air present in refrigerating system

Fault: Poor refrigeration

If refrigerant is added with no evacuation

operation performed, the following gauge
reading will appear:

Symptom

Cause

Analysis

Remedy

●

Pressure at both Hi- and
Lo-pressure ends very
high

●

Lo-pressure piping feel-
ing hot

●

Foam is observed
through the sight glass

●

Air enters the re-
frigerating system

●

Air enters the refriger-
ant system

●

Insuf

cient evacuation

●

Check if compressor
oil is contaminated
or inadequate.

●

Evacuate and add
new refrigerant.

Fig. 4-161

4-161

Structure and Functions

SY365(B)H-9 Crawler Hydraulic Excavator

ZX215-1002174

MPa

{cmHg kgf/cm

}

{cmHg kgf/cm

}

-01

-76

-50

085

8.5

●

Improper installation of expansion valve/
thermal pipe defect (wide opening)

Fault: insuf

cient refrigeration

Symptom

Cause

Analysis

Remedy

●

Pressure at both
Hi- and Lo-pressure
ends very high

●

Frosting or conden-
sation on Lo-pres-
sure piping

●

Improper installation of
thermal pipe/defective
thermal pipe (exces-
sively wide opening)

●

Excessive re-
frigerant in Lo-
pressure piping

●

Expansion
valve opening
too wide

●

Check the installation of
thermal piping

●

If thermal piping is normal,
check the expansion valve.
Replace expansion valve if
found defective.

Fig. 4-162

SANY Crawler Hydraulic Excavator SY365H-9, SY365BH-9. Shop Manual (2014) - page 15