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SANY Crawler Hydraulic Excavator (SY195C9, SY205C9, SY215C9, SY225C9). Shop Manual (2013) - page 25

Troubleshooting

H-15 Travel speed is low

Trouble

Ɣ Machine travel speed is low.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Travel control lever

Pilot valve output pressure

Malfunction of travel

1

Forward

3.5~3.9 MPa

pilot valve

Reverse

{ 36~40 kg/cm²}

Difference occurs between left and

”0.4 MPa

right output

”{4 kg/cm²}

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Malfunction of pilot

Control lever

Control circuit source pressure

2

relief valve

3.5~3.9 MPa

All levers in "NEUTRAL"

{ 36~40 kg/cm²}

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Travel speed

Travel control lever

Reading on monitor

3.5~3.9 MPa

3

Failure of sensor

Lo

Operated

{ 36~40 kg/cm²}

3.5~3.9 MPa

Hi

Operated

{ 36~40 kg/cm²}

Check the sensor by replacing it with another one.

Malfunction of travel

4

Spool of travel control valve may have malfunction. Check it directly.

control valve (spool)

Malfunction of travel

The makeup valve in travel control valve may have malfunction. Check

5

control valve (make-

it directly.

up valve)

Stop the engine. Perform troubleshooting while the engine is running at

Failure of travel mo-

high idle.

6

tor

Travel control lever

Oil leakage of travel motor

Travel relief

27.2 ml/min

Final drive may have internal defect. Check it directly.

Ɣ Internal defect of the final drive can be determined through abnor-

7

Failure of final drive

mal noise, abnormal heat, and metal powder or debris contained in

the oil drained.

7-111

Troubleshooting

H-16 Machine is not steered well or steering power is low

Trouble

Ɣ Machine is not steered well or steering power is low

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is

running at high idle.

Malfunction of travel pilot

Travel control lever

Pilot valve output pressure

1

valve

Both sides in "NEUTRAL"

0 {0}

3.5~3.9 MPa

Either side operated

{ 36~40 kg/cm²}

Ɣ Stop the engine. Perform troubleshooting while the engine is

running at high idle.

Travel control lever

Solenoid valve output pressure

Malfunction of travel pilot

2

3.5~3.9 MPa

Both sides operated

pressure sensor

{ 36~40 kg/cm²}

3.5~3.9 MPa

Either side operated

{ 36~40 kg/cm²}

Malfunction of travel

Spool of travel control valve may have malfunction. Check it direct-

3

control valve (spool)

ly.

Malfunction of travel

The makeup valve in travel control valve may have malfunction.

4

control valve (makeup

Check it directly.

valve)

Seal of relief valve in travel motor may be defective. Check it di-

Failure of travel motor

rectly.

5

(relief valve)

Ɣ The failure of seal can be determined by swapping the front

and back motors or the left and right motors.

Seal of check valve in travel motor may be defective. Check it di-

Failure of travel motor

rectly.

6

(check valve)

Ɣ The failure of seal can be determined by swapping the front

and back motors or the left and right motors.

7-112

Troubleshooting

H-17 Travel speed cannot be changed

Trouble

Ɣ Travel speed cannot be changed.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Solenoid valve output

Malfunction of travel

Travel speed

Travel control lever

pressure

1

speed shifting solenoid

Lo

Operated

0 {0}

valve

3.5~3.9 MPa

Hi

Operated

{ 36~40 kg/cm²}

Failure of travel motor (in

Speed shifting assembly of travel motor may have malfunction.

2

speed change)

Check it directly.

7-113

Troubleshooting

H-18 Travel system fails (only at one side)

Trouble

Ɣ One side of the tracks cannot make a turn.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Defective seat of travel

Seat of makeup valve in travel control valve may have malfunction.

1

control valve (makeup

Check it directly.

valve)

Defective seat of travel

Seat of relief valve in travel control valve may have malfunction.

2

motor (relief valve)

Check it directly.

Defective seat of travel

Seat of check valve in travel motor valve may have malfunction.

3

motor valve (makeup

Check it directly.

valve)

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Speed of travel motor

4

Travel control lever

Leakage from travel motor

drops.

Travel relief

27.2 ml/min

Final drive may have internal defect. Check it directly.

Ɣ Internal defect of final drive can be determined with abnormal

5

Failure of final drive

noise, overheat, and metal powder or debris contained in the oil

drained.

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Travel control lever

Pilot valve output pressure

Defective pilot pressure

Forward

3.5~3.9MPa

6

sensor

Reverse

{ 36~40 kg/cm²}

Difference occurs between left and

0.4 MPa {4 kg/cm²}

right output

Check it with swapping method.

7-114

Troubleshooting

H-19 Swing operation fails

Trouble (1)

Ɣ Upper structure fails to swing in either direction.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Malfunction of swing

1

Parking brake of swing motor may have malfunction. Check it directly.

motor (parking brake)

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Improper adjustment

Swing control lever

Swing relief pressure

or malfunction of

25.5~28.5 MPa

2

Swing relief

swing motor (relief

{260~291 kg/cm²}

valve)

If oil pressure does not become normal after adjustment, swing motor

relief valve may have malfunction or internal defect. Check the relief

valve directly.

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

3

Failure of swing motor

Swing control lever

Leakage from swing motor

Swing relief

•10 ml/min

Swing mechanism may have internal defect. Check it directly.

Failure of swing

Ɣ Internal defect of swing mechanism can be determined with ab-

4

mechanism

normal noise, overheat, and metal powder or debris contained in

the oil drained.

7-115

Troubleshooting

Trouble (2)

Ɣ Upper structure only fails to swing in one direction.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Malfunction of pilot

Left control lever

Pilot valve output pressure

1

valve

"NEUTRAL"

0 {0}

Swing

•3.5MPa {•36 kg/cm²}

Malfunction of swing

2

Spool of swing control valve may have malfunction. Check it directly.

control valve (spool)

Defective seal of

Seal of makeup valve in swing motor may have defect. Check it directly.

3

swing motor (makeup

Ɣ Failure of the seal can be determined by swapping the right and left

valve)

makeup valves and check for any changes.

7-116

Troubleshooting

H-20 Swing acceleration poor or swing speed low

Trouble (1)

Ɣ Swing acceleration is poor, or swing speed is low.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Malfunction of swing

1

Parking brake of swing motor may have malfunction. Check it directly.

motor (parking brake)

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Swing control lever

Swing relief valve

Improper adjustment

or malfunction of

25.5~28.5 MPa

2

Swing relief

swing motor (relief

{260~291 kg/cm²}

valve)

If oil pressure does not become normal after adjustment, swing motor

relief valve may have malfunction or internal defect. Check the relief

valve directly.

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Failure of swing mo-

3

Swing control lever

Leakage from swing motor

tor

Swing relief

”10 ml/min

Clogging of brake

4

Disassemble, clean and check.

control lines

7-117

Troubleshooting

Ɣ Swing acceleration is only poor on one side, or swing speed is

Trouble (2)

low.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Malfunction of pilot

Swing control lever

Pilot valve output pressure

1

valve

"NEUTRAL"

0 {0}

Left swing

•3.5MPa {•36 kg/cm²}

Right swing

Malfunction of swing

Pressure compensation valve of swing motor may have malfunction.

2

motor (pressure com-

Check it directly.

pensation valve)

Seal of makeup valve in swing motor may have defect. Check it di-

Defective seal of swing

rectly.

3

motor (makeup valve)

Ɣ Swap the left and right makeup valves and observe the result in

order to determine whether the seal fails.

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

One-side leakage of

Swing control lever

Pilot valve output pressure

4

swing pilot pressure

"NEUTRAL"

0 {0}

sensor (shuttle valve)

Left swing

3.5~3.9MPa {36~40 kg/cm²}

Right swing

7-118

Troubleshooting

H-21 Upper structure overruns remarkably when it stops swinging

Ɣ Upper structure overruns remarkably when it stops swinging in

Trouble (1)

both directions.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Swing control lever

Swing relief pressure

Improper adjustment

25.5~28.5 MPa

1

or malfunction of swing

Swing relief

{260~291 kg/cm²}

motor (relief valve)

If oil pressure does not become normal after adjustment, swing motor

relief valve may have malfunction or internal defect. Check the relief

valve directly.

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

2

Failure of swing motor

Control lever

Leakage from swing motor

Swing relief

”10 ml/min

Trouble (2)

Ɣ Swing acceleration is only poor on one side, or swing speed is low.

Ɣ Set the working mode at gear (10) of power mode (S) to perform

Related information

troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is

running at high idle.

Swing control lever

Pilot valve output pressure

1

Malfunction of pilot valve

"NEUTRAL"

0 {0}

Left swing

•3.5MPa {•36 kg/cm²}

Right swing

Malfunction of swing con-

Spool of swing control valve may have malfunction. Check it direct-

2

trol valve (spool)

ly.

Seal of makeup valve in swing motor may be defective. Check it

Malfunction or defec-

directly.

3

tive seal of swing motor

Ɣ Swap the left and right makeup valves and observe the result

(makeup valve)

in order to determine whether the seal fails.

7-119

Troubleshooting

H-22 Large shock is produced when upper structure stops swinging

Trouble

Ɣ Large shock is produced when upper structure stops swinging.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Ɣ Stop the engine. Perform troubleshooting while the engine is run-

ning at high idle.

Swing control lever

Pilot valve output pressure

Malfunction of swing

1

pilot valve

"NEUTRAL"

0 {0}

Left swing

•3.5MPa {•36 kg/cm²}

Right swing

Reverse prevention valve of swing motor may have malfunction.

Malfunction of swing

Check it directly.

2

reverse prevention

Ɣ Replace the valve with a new on in order to determine whether the

valve

valve fails.

Malfunction of swing

3

Swing relief valve may be worn or sluggish.

relief valve

H-23 High noise is produced when upper structure stops swinging

Trouble

Ɣ High noise is produced when upper structure stops swinging.

Ɣ Set working mode to (S) and fuel control dial at position (10) to

Related information

carry out troubleshooting.

Cause

Standard value in normal state/Remarks on troubleshooting

Malfunction of back

1

Back pressure valve may have malfunction. Check it directly.

pressure valve

Malfunction of swing

2

Relief valve of swing motor may have malfunction. Check it directly.

motor (relief valve)

Seal of makeup valve in swing motor may have malfunction. Check it

Malfunction of swing

directly.

3

motor (makeup valve)

Ɣ Swap the left and right makeup valves and observe the result in

order to determine whether the seal fails.

The swing mechanism is suspected of an internal failure. Check the

inside of the machinery itself.

Failure of swing mecha-

4

Ɣ Internal defect of swing mechanism can be determined with ab-

nism

normal noise, overheat, and metal powder or debris contained in

the oil drained.

7-120

Troubleshooting

H-24 Swing drift excessive

Ɣ Hydraulic drift of swing is large (when swing holding brake is ap-

Trouble (1)

plied).

Ɣ When swing lock switch is turned ON or when swing holding

Related information

brake release switch is in normal position, swing holding brake

operates and upper structure is fixed with disc brake.

Cause

Standard value in normal state/Remarks on troubleshooting

Failure of swing hold-

Swing holding brake control lines and holding brake pilot valve may be

1

ing brake control lines

defective. Check them directly.

Malfunction of swing

2

Parking brake of swing motor may have malfunction. Check it directly.

motor (parking brake)

Ɣ Hydraulic drift of swing is large (when swing holding brake is re-

Trouble (2)

leased).

Ɣ When swing holding brake release switch is in release position,

Related information

swing holding brake is released and upper structure is secured

by only hydraulic pressure.

Cause

Standard value in normal state/Remarks on troubleshooting

Malfunction or defec-

Swing control valve spool may have malfunction or defective seal.

1

tive seal of swing

Check it directly.

control valve (spool)

Failure of swing motor

2

Seal of relief valve in swing motor may be defective. Check it directly.

(relief valve)

Failure of swing motor

Seal of makeup valve in swing motor may be defective. Check it di-

3

(makeup valve)

rectly.

7-121

Disassembly and Assembly

8.1.4 The symbols used in this section

This section uses some symbols and icons that are not used elsewhere in this manual. They in-

clude:

This symbol indicates the amount of oil or water to be discharged.

This symbol indicates that specific coating agent must be used.

This symbol indicates the lubricant required.

This symbol indicates a torque specified.

This symbol indicates the amount of oil or water to be added.

This symbols indicates the weight of a component or an assembly.

8.2 Operating Precautions

The following precautions must be observed before removing or installing (disassembling or as-

sembling) a component.

1.

Precautions to be observed prior to removal operation

Ɣ

Dispose the engine coolant properly if antifreeze is contained in the engine coolant.

Ɣ

After disconnecting a hose or tube, cover or plug must be used to prevent invasion of dirt

or dust.

Ɣ

A suitable container must be prepared to collect oil when draining the oil.

Ɣ

Matching mark must be made at where is necessary before removing in order to avoid

mistake during reinstallation.

Ɣ

Do not pull the wire and avoid the wire coming off. To avoid excessive force imposing on

the wire, hold the connector when disconnecting a wire.

Ɣ

Tag the wires and the hoses in order to ensure their connecting positions. By doing so,

mistakes can be avoided during reinstallation.

Ɣ

Count and check the number and thickness of the shims, and keep them in a safe place.

Ɣ

When raising or lifting components, be sure to use proper lifting equipment of ample

strength and safety.

Ɣ

When forcing screws are used to remove any components, tighten the screws evenly in

turn.

Ɣ

The surrounding area must be cleaned before removing a unit. Cover the unit after remov-

al in order to prevent invasion of dirt or dust.

8-6

Disassembly and Assembly

Ɣ

Precautions to be observed when disassembling the lines

The lines disassembled must be blinded with plugs.

A: Thread-connected hoses

I.D. (mm)

Code

Description

Light Thread Connection

6

B210780001189

Plug

8

B210780001190

Plug

10

B210780000077

Plug

12

B210780000078

Plug

15

B210780000883

Plug

20

B210780000079

Plug

22

60056667

Plug

Heavy Thread Connection

12

B210780001142

Plug

16

60002397

Plug

20

B210780000080

Plug

25

B210780000081

Plug

B: Thread-connected adaptors (plug and nut used in combination)

I.D. (mm)

Code

Description

Code

Description

Light Thread Connection

6

B210780000903

Taper bore plug

23002925

Nut

8

B210780001146

Plug

B210770000011

Nut

10

B210780000088

Plug

B210334000011

Nut

12

B210780000089

Plug

B210334000012

Nut

15

B210780000882

Plug

B210334000004

Nut

20

B210780000090

Plug

B210334000010

Nut

22

B210780000091

Plug

B210780000112

Nut

Heavy Thread Connection

12

B210780001143

Plug

B210780000406

Nut

16

A820205001523

Plug

B210780000405

Nut

20

B210780000902

Plug

B210780000904

Nut

25

B210780001172

Plug

B210334000006

Nut

8-7

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