SANY Crawler Hydraulic Excavator SY195C9, SY205C9, SY215C9, SY225C9. Service Manual

6-40

Testing and Adjusting

6.17

Residual Pressure in Hydraulic Circuit - Release

NOTE: Even if the swing motor circuit and
the travel motor circuit are free from re-
sidual pressure, they will be in

uenced by

the internal pressure of hydraulic tank. The
breather valve must therefore be opened
to release pressure prior to such operation.

1. Stop the engine, loosen the butter

y nut on

the breather valve, and press the release
button to release the pressure in hydraulic
tank.

2. Turn the engine start switch to the ON

position and operate the control levers for
several times.

●

The pilot lock valve must be energized.
Operate the control levers with the en-
gine start switch in the ON position.

●

The pressure in accumulator will be
released after the control levers have
been operated 2 or 3 times.

3. Start the engine and keep the engine run-

ning at low idle for about 10 seconds in
order to increase the pressure in accumu-
lator. Stop the engine.

4. Repeat the above step 2 through step 3

several times.

CAUTION

●

Release the residual pressure in the hy-
draulic circuit before disconnecting the
lines between the hydraulic cylinders
or between the hydraulic motor and the
control valve.

6-41

Testing and Adjusting

6.18 Oil Leakage - Measure

1. Measure oil leakage from boom cylinder

1) Start the engine and keep it running un-

til the hydraulic oil temperature is within
the operational range. Fully extend the
boom cylinder.

NOTE: Release the residual pressure
in the circuits.

See “Residual Pressure in Hydraulic
Circuit - Release” on page 6-40.

2) Disconnect the hose (1) on the cylinder

head side and plug the hose end with a
cap.

NOTE: Be careful not to disconnect the
hose on the cylinder bottom side.

3) Start the engine and apply relief pres-

sure to the bottom side of the cylinder
while the engine is running at high idle.

4) Hold this condition for 30 seconds.

Measure oil leakage for one minute.

5) Make sure that the machine returns to

its normal condition after measurement.

ZXT215-1004010

6-42

Testing and Adjusting

2. Measure oil leakage from arm cylinder

1) Start the engine and keep it running un-

til the hydraulic oil temperature is within
the operational range. Fully extend the
arm cylinder.

NOTE: Release the residual pressure
in the circuits.

See “Residual Pressure in Hydraulic
Circuit - Release” on page 6-40.

2) Disconnect the hose (2) on the cylinder

head side and plug the hose end with a
cap.

NOTE: Be careful not to disconnect the
hose on the cylinder bottom side.

3) Start the engine and apply relief pres-

sure to the bottom side of the cylinder
while the engine is running at high idle.

4) Hold this condition for 30 seconds.

Measure oil leakage for one minute.

5) Make sure that the machine returns to

its normal condition after measurement.

ZXT225-1104007

6-43

Testing and Adjusting

3. Measure oil leakage from bucket cylin-

der

1) Start the engine and keep it running un-

til the hydraulic oil temperature is within
the operational range. Fully extend the
bucket cylinder.

NOTE: Release the residual pressure
in the circuits.

See “Residual Pressure in Hydraulic
Circuit - Release” on page 6-40.

2) Disconnect the hose (3) on the cylinder

head side and plug the hose end with a
cap.

NOTE: Be careful not to disconnect the
hose on the cylinder bottom side.

3) Start the engine and apply relief pres-

sure to the bottom side of the cylinder
while the engine is running at high idle.

4) Hold this condition for 30 seconds.

Measure oil leakage for one minute.

5) Make sure that the machine returns to

its normal condition after measurement.

ZXT225-1104008

6-44

Testing and Adjusting

4. Measure oil leakage from swing motor

1) Fully extend the work equipment. Lower

the bucket on the ground and raise the
machine slightly. Secure machine from
rotating clockwise or counter clockwise
while testing. Stop the engine.

2) Disconnect the hose (4) and the hose

(5). Plug the hose ends with caps.

3) Start the engine and apply relief pres-

sure to the bottom side of the swing
motor while the engine is running at
high idle. Measure oil leakage under
this condition.

●

Hold the condition described in step 3)
for 30 seconds. Measure oil leakage for
one minute.

●

After the first measurement, turn the
upper structure 180°and measure the
leakage again in the same way.

4) Make sure that the machine returns to

its normal condition after measurement.

ZXT225-1104006

6-45

Testing and Adjusting

5. Measure oil leakage from travel motor

1) Remove the cover of the travel motor.

2) Start the engine and lock the travel

mechanism.

NOTE: Insert pin (1) between the
sprocket and the track frame to lock the
travel mechanism.

ZXT215-1004014

ZXT215-1004004

3) Disconnect the drain hose (6) of the

travel motor. Plug the hose end with a
cap.

4) Start the engine and apply relief pres-

sure to the bottom side of the travel
motor while the engine is running at
high idle. Measure oil leakage under
this condition.

●

Hold the condition described in step 4)
for 30 seconds. Measure oil leakage for
one minute.

●

Rotate the motor slightly. Change the
positions of the valve plate and the
travel motor and of the cylinder and pis-
ton. Repeat the measurement several
times.

5) Make sure that the machine returns to

its normal condition after measurement.

WARNING

●

During measurement, mis-operation of
the control levers can cause serious ac-
cidents. Make sure that all signals are
given correctly.

6-46

Testing and Adjusting

6.19

Air in Each Component - Bleed

Air bleeding item

Contents of work

Air bleeding procedures

Bleed air

from hydrau-

lic pump

Starting

engine

Bleed

air from

cylinder

Bleed air

from swing

motor

Bleed air

form travel

motor

Starting

operation

●

Replacing hydraulic oil

●

Cleaning

lter element

○

(Note)

○

(Note)

○

●

Replacing return

lter element

○

●

Repairing/replacing hydraulic pump

●

Removing suction piping

○

●

Repairing/replacing control valve

○

●

Replacing cylinder

●

Removing cylinder piping

○

●

Replacing swing motor

●

Removing swing motor piping

○

●

Replacing travel motor

●

Removing travel motor piping

○

NOTE: Bleed air from the swing motor and
travel motor only when the oil in the motor
cases is drained.

1. Bleed air from hydraulic pump

1) Loosen the air bleeder (1) and check

that oil oozes out through the air bleed-
er.

2) Tighten the air bleeder (1) if oil is seen.

Bleeder:

7.8~9.8 N·m{0.8~1.0 kgf·m}

NOTE: Run the engine at low idle for
10 minutes after bleeding the air ac-
cording to the above procedure.

ZXT215-1004015

6-47

Testing and Adjusting

2. Bleed air from hydraulic cylinder

1) Start the engine and keep the engine

running at low idle for 5 minutes.

2) Raise or lower the boom 4 or 5 times

with the engine running at low idle.

NOTE: Be careful not to apply relief
pressure. Stop the piston when the rod
is about 100 mm before stroke end.

3) Repeat step 2) with the engine running

at high idle.

4) While running the engine at low idle,

move the piston rod to the stroke end
and apply relief pressure.

5) Bleed air from arm cylinder and bucket

cylinder by performing step 2) through
step 4).

NOTE: When a new cylinder is in-
stalled for replacement, bleed the air
from the new cylinder before mounting
it to the work equipment. Especially the
boom cylinder, once mounted to the
work equipment, its piston rod is un-
able to reach its stroke end in lowering
operation. Therefore, the air must be
bled from the boom cylinder before it is
mounted to the work equipment.

3. Bleed air from swing motor

1) Start the engine and run the engine at

low idle.

2) Bleed air from the swing motor by turn-

ing the upper structure slowly.

Testing and Adjusting

Table of monitored items

Monitored Item

Unit

Remark

Controller Mode Selection

Graph

High/Low Travel Speed Selection

Graph

Auto Idle Selection

Graph

Engine Speed

r / min

Pressure - Front pump

Pressure - Rear pump

Current - Proportional Valve (Solenoid, Front pump)

Current - Proportional Valve (Solenoid, Rear pump)

Pilot Pressure - Boom Raise

Pilot Pressure - Boom Lower

Pilot Pressure - Arm In

Pilot Pressure - Arm Out

Pilot Pressure - Bucket Curl

Pilot Pressure - Bucket Dump

Pilot Pressure - Swing

Pilot Pressure - Travel Left

Pilot Pressure - Travel Right

Solenoid
Valve 1

Bucket Con

uence

ON / OFF

Swing Priority

ON / OFF

Hi/Lo Speed Switching

ON / OFF

Voltage - Fuel Control Dial

Voltage - Motor Position

Temperature - Engine Coolant

°C

Gauge reading

Temperature - Hydraulic oil

°C

Gauge reading

Pressure - Engine Oil

KPa

Troubleshooting

7-1

7 Troubleshooting

7.1 Points to Remember When Troubleshooting ........................................................... 7-3
7.2 Troubleshooting Procedures .................................................................................... 7-5
7.3 Connector Location and Electrical Circuit Diagram ................................................. 7-8

7.3.1  Connector location layout ............................................................................ 7-12
7.3.2  Electrical element circuit diagram (cab circuit)............................................. 7-18
7.3.3  Electrical control circuit diagram (engine circuit).......................................... 7-20
7.3.4  Electrical control circuit diagram (sensor and solenoid valve circuit) ........... 7-22
7.3.5  SWP type connector .................................................................................... 7-23
7.3.6  A/AMP type connector ................................................................................. 7-24
7.3.7  DT type connector ....................................................................................... 7-25

7.4  Failure Symptoms and Troubleshooting Codes ..................................................... 7-26
7.5  Troubleshooting with an Event Code ..................................................................... 7-28
7.6  Troubleshooting of Electrical System (E - Mode)................................................... 7-63
7.7  Troubleshooting of Hydraulic and Mechanical Systems (H - Mode) ...................... 7-93

7-3

Troubleshooting

TROUBLESHOOTING

7.1

Points to Remember When Troubleshooting

The aim of troubleshooting is to pinpoint the
basic cause of the failure, to carry out repairs
swiftly, and to prevent reoccurrence of the fail-
ure.

When carrying out troubleshooting, important
point is to understand the structure and func-
tion.

However, a short cut to effective troubleshoot-
ing is to ask the operator various questions
to form some idea of possible causes of the
failure that would produce the reported symp-
toms.

1. When carrying out troubleshooting, do not

hurry to disassemble the components.

If components are disassembled immedi-
ately any failure occurs:

●

Parts that have no connection with the
failure or other unnecessary parts will
be disassembled.

●

It will become impossible to find the
cause of the failure.

It will also cause a waste of man-hours,
parts, or oil or grease, and at the same
time, will also lose the confidence of the
user or operator.

For this reason, when carrying out
troubleshooting, it is necessary to carry out
thorough prior investigation and to carry
out troubleshooting in accordance with the

xed procedure.

2. Points to ask user or operator:

1) Have any other problems occurred apart

from the problem that has been reported?

2) Was there anything strange about the

machine before the failure occurred?

3) Did the failure occur suddenly, or were

there problems with the machine condition
before this?

4) Under what conditions did the failure oc-

cur?

5) Had any repairs been carried out before

●

Stop the machine in a level ground, and check that lock pins, blocks, and parking brake are
securely

tted.

●

When carrying out the operation with two or more workers, keep strictly to the agreed signals,
and do not allow any unauthorized person to come near.

●

If the radiator cap is removed when the engine is hot. Hot coolant may spurt out and cause
burns, so wait for the engine to cool down before starting troubleshooting.

●

Be extremely careful not to touch any hot parts or to get caught in any rotating parts.

●

When disconnecting wiring, always disconnect the negative (–) terminal of the battery

rst.

●

When removing the plug or cap from a location which is under pressure from oil, water, or air,
always release the internal pressure

rst. When installing measuring equipment, be sure to

connect it properly.

7-4

Troubleshooting

the failure? When were these repairs car-
ried out?

6) Has the same kind of failure occurred be-

fore?

3. Check before troubleshooting

1) Check the oil level.

2) Check for any external leakage of oil from

the piping or hydraulic equipment.

3) Check the travel of the control levers.

4) Check the stroke of the control valve spool.

5) Other maintenance items can be checked

externally, so check any item that is con-
sidered to be necessary.

4. Con

rming failure

●

Confirm the extent of the failure yourself,
and judge whether to handle it as a real
failure or as a problem with the method of
operation, etc.

NOTE: When operating the machine to
reenact the troubleshooting symptoms, do
not carry out any investigation or measure-
ment that may make the problem worse.

5. Troubleshooting

●

Use the results of the investigation and
inspection in Items 2 – 4 to narrow down
the causes of failure, then use the trouble-
shooting

owchart to locate the position of

the failure exactly.

●

The basic procedure for troubleshooting is
as follows.

1) Start from the simple points.

2) Start from the most likely points.

3) Investigate other related parts or informa-

tion.

6. Measures to remove root cause of failure

●

Even if the failure is repaired, if the root
cause of the failure is not repaired, the
same failure will occur again. To prevent
this, always investigate why the problem
occurred. Then, remove the root cause.

7-5

Troubleshooting

7.2 Troubleshooting Procedures

If some phenomenon occurs on a machine that looks like a failure, identify the corresponding
troubleshooting No. and proceed to the explanations for diagnosis.

Follow six steps listed below to diagnose and analyze for troubleshooting, and

nd the causes

and work out the corresponding methods.

1. Read related technical manuals in detail.

Have a knowledge of related system,
principle of operation, and structure,
function and technical specification of
parts.

2. Ask operator

Before checking, ask related person, i.e.
the operator for all information about the
failure.

a. Current working condition of machine

(Whether machine is operated prop-
erly).

b. When troubles are found and what kind

of operation does machine perform at
that time?

c. Development of troubles (Whether

troubles are becoming severer or occur
for the

rst time.)

d. What kind of trouble did machine have

before?

For example: Which parts have been
repaired or replaced?

e. What has been done after troubles take

place and how about the reaction?

f. Will the trouble reoccur? Does the trou-

ble occur regularly?

3. Check before starting

Before starting troubleshooting, check
the operator's records on operation,
maintenance and service of the machine.
Understand whether related personnel has
done wrong in operation, maintenance and
service. Check for wrong operation and
maintenance at the same time.

7-6

Troubleshooting

Item

Criterion

Remedy

Lubricating oil, coolant

1. Check fuel level and type of fuel
2. Check for impurities in fuel
3. Check hydraulic oil level
4. Check hydraulic oil strainer
5. Check swing drive oil level
6. Check engine oil level (in oil pan)
7. Check coolant level
8. Check dust indicator for clogging
9. Check hydraulic

lter

10. Check

nal drive oil level

—
—
—
—
—
—
—
—
—
—

Add fuel
Clean, drain
Add oil
Clean, drain
Add oil
Add oil
Add water
Clean or replace
Replace
Add oil

Electrical equipment

1. Check for looseness, corrosion of battery terminal and
wiring
2. Check for looseness, corrosion of alternator terminal
and wiring
3. Check for looseness, corrosion of start motor terminal
and wiring

—
—
—

Tighten or replace

Hydraulic,

mechanical

equipment

1. Check for abnormal noise and smell
2. Check for oil leakage
3. Bleeding air

—
—
—

Repair
Repair
Bleed air

Electrics, electrical equipment

1. Check battery voltage (with engine stopped)
2. Check electrolyte level
3. Check for discolored, burnt, exposed wiring
4. Check for missing wiring clips and hanging wiring
5. Check for wet wires (esp. wet connectors or terminals)
6. Check for blown or corroded fuses
7. Check alternator voltage (with engine speed at middle
or higher)
8. Check operating sound of battery relay (when start
switch is turned ON or OFF)

20-30V

—
—
—
—

—

After running for

several minutes:

27.5~ 29.5V

—

Replace
Add or replace
Replace
Repair
Disconnect con-
nector and dry

Replace
Replace
Replace

SANY Crawler Hydraulic Excavator SY195C9, SY205C9, SY215C9, SY225C9. Service Manual - page 23