PDF Troubleshooting Manual TCM E820 3 Wheel Loader - 904 KB
Quickly diagnose and resolve issues with your TCM E820 3-Wheel Loader using this specialized troubleshooting manual.
This technical guide provides systematic procedures for identifying the root cause of mechanical and electrical problems.
It is an invaluable resource for mechanics, saving time and money by enabling efficient and accurate repairs.
Keep your loader running smoothly and minimize downtime with this expert manual.
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--- Page 1 ---
Troubleshooting
No.M-025-MAE
TECHNICAL MANUAL E820-3 No.M-025-MAE
Troubleshooting
--- Page 3 ---
SAFETY
OPERATE ONLY FROM OPERATOR'S
SEAT
• Inappropriate engine starting procedures may cause
the machine to runaway, possibly resulting in seri-
ous injury or death.
• Start the engine only when seated in the opera-
tor's seat.
• NEVER start the engine while standing on the
track or on ground.
• Do not start engine by shorting across starter
terminals.
• Before starting the engine, confirm that all control
levers are in neutral.
• Before starting the engine, confirm the safety SA-431
around the machine and sound the horn to alert
bystanders.
012-E01B-0431
JUMP STARTING
• Battery gas can explode, resulting in serious injury.
• If the engine must be jump started, be sure to
follow the instructions shown in the “OPERATING
THE ENGINE” chapter in the operator’s manual.
• The operator must be in the operator’s seat so
that the machine will be under control when the
engine starts.
• Jump starting is a two-person operation.
• Never use a frozen battery.
• Failure to follow correct jump starting procedures
could result in a battery explosion or a runaway
machine.
SA-032
SA-8
--- Page 4 ---
SAFETY
PROTECT AGAINST FLYING DEBRIS
• If flying debris hit eyes or any other part of the body,
serious injury may result.
• Guard against injury from flying pieces of metal or
debris; wear goggles or safety glasses.
• Keep bystanders away from the working area
before striking any object.
031-E01A-0432
SA-432
PARK MACHINE SAFELY
To avoid accidents:
• Park machine on a firm, level surface.
• Lower bucket to the ground.
• Place the forward/reverse lever (switch) in neutral,
and turn the parking brake switch (lever) in the
ON (parking brake) position.
• Run engine at low idle speed without load for 5
minutes.
• Turn key switch to OFF to stop engine.
• Remove the key from the key switch.
• Lower the lock lever to the LOCK position.
• Close windows, roof vent, and cab door. SA-456
• Lock all access doors and compartments.
033-E07B-0456
STORE ATTACHMENTS SAFELY
• Stored attachments such as buckets, hydraulic
hammers, and blades can fall and cause serious
injury or death.
• Securely store attachments and implements to
prevent falling. Keep children and bystanders
away from storage areas.
504-E01A-0034
SA-034
SA-18
--- Page 5 ---
SAFETY
AVOID HEATING NEAR PRESSURIZED
FLUID LINES
• Flammable spray can be generated by heating near
pressurized fluid lines, resulting in severe burns to
yourself and bystanders.
• Do not heat by welding, soldering, or using a torch
near pressurized fluid lines or other flammable
materials.
• Pressurized lines can be accidentally cut when
heat goes beyond the immediate flame area. In-
stall temporary fireresistant guards to protect
hoses or other materials before engaging in
SA-030
welding, soldering, etc..
AVOID APPLYING HEAT TO LINES CON-
TAINING FLAMMABLE FLUIDS
• Do not weld or flame cut pipes or tubes that con-
tain flammable fluids.
• Clean them thoroughly with nonflammable solvent
before welding or flame cutting them.
510-E01B-0030
REMOVE PAINT BEFORE WELDING OR
HEATING
• Hazardous fumes can be generated when paint is
heated by welding, soldering, or using a torch. If
inhaled, these fumes may cause sickness.
• Avoid potentially toxic fumes and dust.
• Do all such work outside or in a well-ventilated
area. Dispose of paint and solvent properly.
• Remove paint before welding or heating:
1. If you sand or grind paint, avoid breathing the dust.
Wear an approved respirator.
2. If you use solvent or paint stripper, remove strip-
per with soap and water before welding. Remove SA-029
solvent or paint stripper containers and other
flammable material from area. Allow fumes to
disperse at least 15 minutes before welding or
heating.
511-E01A-0029
SA-28
--- Page 6 ---
OPERATIONAL PERFORMANCE TEST / Introduction
PREPARATION FOR PERFORMANCE
TESTS
Observe the following rules in order to carry out
performance tests accurately and safely.
THE MACHINE
1. Repair any defects and damage found, such as
oil or water leaks, loose bolts, cracks and so on,
before starting to test.
TEST AREA
1. Select a hard and flat surface.
2. Secure enough space to allow the machine to
run straight more than 200 m (656 ft 2 in), and to
operate steering.
3. If required, rope off the test area and provide
signboards to keep unauthorized personnel
away.
PRECAUTIONS
1. Before starting to test, agree upon the signals to
be employed for communication among cowork-
ers. Once the test is started, be sure to commu-
nicate with each other using these signals, and to
follow them without fail.
2. Operate the machine carefully and always give
first priority to safety.
3. While testing, always take care to avoid acci-
dents due to landslides or contact with
high-voltage power lines. Always confirm that
there is sufficient space for full swings.
4. Avoid polluting the machine and the ground with
leaking oil. Use oil pans to catch escaping oil. T105-06-01-003
Pay special attention to this when removing hy-
draulic pipings.
MAKE PRECISE MEASUREMENT
1. Accurately calibrate test instruments in advance
to obtain correct data.
2. Carry out tests under the exact test conditions
prescribed for each test item.
3. Repeat the same test and confirm that the test
data obtained can be produced repeatedly. Use
mean values of measurements if necessary.
T4-1-2
--- Page 7 ---
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
SERVICE BRAKE CAPACITY
Summary: 6. Repeat the measurement three times and calcu-
1. The overall performance of the service brake is late the mean values.
judged.
2. The braking capability of the brake is an item of Evaluation:
safety control. Conduct the performance test Refer to Operational Performance Standard in T4-2.
correctly.
Preparation: Remedy:
1. Adjust air pressure of the tires evenly in advance. Refer to Trouble Shooting in T5.
2
240 KPa (2.4 kgf/cm ) at tire size 17.5/65-20-10PR
(L-2)
2. On a paved dry ground, prepare a 350 m (1148 ft)
straight travel course (a 300 m (984 ft) of accel-
eration/deceleration zone and a 50 m (164 ft) of
measurement road), and set the brake starting
0.3 to 0.4 m
point. (12” to 1’4”)
3. Empty the bucket, and hold the lift arm at 0.3 to
0.4 m (12 in to 1 ft 4 in) above the ground.
Stopping Distance
4. Keep hydraulic oil temperature at 50±5 °C (122±9
Stopping Point Brake Starting T4FG-04-04-002
°F). Warm the axle oil by repeating travel and Point
brake operations.
Warm up the engine so that the needle of the in-
dicators of the engine coolant temperature gauge
rise above the horizontal positions.
Measurement:
CAUTION: Avoid measurement during travel
reverse operation for dangers.
(FNR switch: F)
1. Measurement for high-speed mode.
2. Select the pedal, switch, and forward/reverse
lever as follows.
High-Low Selector Accelerator eco Mode
Parking Brake Switch
Switch Pedal Switch
High (2nd gear) OFF Full depression OFF
3. Set the forward/reverse lever at the F (Forward)
position. From the acceleration zone, travel at the
maximum speed 34 km/h (21 mph) by depression
the accelerator pedal to the stroke end.
4. Depress the brake pedal at the brake starting
point, and completely stop the vehicle. (Right
Service Brake Pedal)
5. Measure the distance from the brake starting
point to the point where the front tire is contacting.
T4-4-2
--- Page 8 ---
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
DIG FUNCTION DRIFT CHECK
Summary:
1. Internal leakage of the lift arm, bucket cylinders
and control valves when the buket is loaded with
load equivalent to the standard load is judged by
the settlement (shrinkage) of the cylinder rod.
2. Measurement is made in the standard front at-
tachment configuration (standard bucket).
3. When measurement is made immediately after
the cylinder replacement, conduct air venting of
the cylinder before measurement by slowly oper-
ating the cylinders to the both stroke ends several
times.
Preparation:
1. Load the bucket with weight or sand equivalent to
the standard load.
Bucket Cylinder
1440 kg (3170 lb)
2. In the front attachment position, extend the lift arm
to the maximum reach, and hold the bucket at an
angle of about 5° declined forward from full tilting.
CAUTION: Do not allow any persons to be
under the bucket.
1. Keep hydraulic oil temperature at 50±5 °C (122±9 Lift Arm Cyl-
°F). inder
Measurement:
1. Stop the engine.
2. After 15 minutes, measure the shrinkage of the lift T4FG-04-04-009
arm cylinder and the shrinkage of the bucket cyl-
inder respectively. (Shrinkage dimension=A-B)
3. Repeat the measurement three times and calcu-
late the mean values.
Evaluation:
B
Refer to Operational Performance Standard in T4-2.
A
T4FG-04-04-010
Remedy:
Refer to Trouble Shooting in T5.
T4-4-12
--- Page 9 ---
OPERATIONAL PERFORMANCE TEST / Component Test
OVERLOAD RELIEF PRESSURE
Summary:
1. The circuit pressure should be increased by 3. Start the engine. Check for oil leakage at the
applying an external force while blocking the pressure gauge connection.
return circuit from the control valve. This 4. Maintain hydraulic oil temperature at 50±5 °C
measuring method is hazardous and the results (122±9 °F).
obtained with this method are unreliable.
2. The oil flow rate used to set the overload relief Measurement:
pressure is far less than that used to set the main 1. Set engine speed at fast idle. Depress the
relief pressure. Therefore, measuring the accelerator pedal fully.
overload pressure in the main circuit by 2. Operate the lift arm or bucket control lever for the
increasing the main relief set pressure more than overload relief valve to be measured. Operate the
the overload valve set-pressure is not a proper cylinder to the stroke end (extend/retract).
method. In addition, in case a main relief valve 3. Read the pressures on the pressure gauge at this
designed to leak a small quantity of oil before time.
reliving is used, its pre-leaking start pressure 4. Repeat the measurement three times and
should be increased more than the overload relief calculate the mean values.
valve set pressure. However, the pre-leaking start
pressure is not always increased more than the Evaluation:
overload relief valve set-pressure as the In case the pressure of the bucket or lift arm circuit
adjustable upper limit of the main relief valve which has been measured is specification of the main
set-pressure is provided. Accordingly, the relief valve set pressure, this is normal.
overload relief valve assembly should be Refer to Orerational Performance Standard in T4-2.
removed from the machine and checked on a
specified test stand at a correct oil flow rate.
Some overload relief valves come in contact with
the control valve body to block the oil passage.
When this type of overload relief valve is checked,
the control valve body should be precisely Pressure
Gauge
finished as the test unit. Provide one control valve
other than that on the machine as a test kit.
3. If the overload relief valve performance should be Adapter
1
checked on the machine, however, measure the
main relief pressure while releasing each front
function respective to the measuring overload
relief valve. And, assume that the overload relief
valve is functioning correctly if the obtained main
relief pressure is within the specified value range.
Measure the main pressure of the front functions.
T4FG-04-05-010
Preparation:
1. Stop the engine.
2. Remove the plug from the pressure check port (1)
at the tilt cylinder bottom side. Install an adapter
(G1/8), a hose, and a pressure gauge.
: 5 mm (0.20 in)
T4-5-8
--- Page 10 ---
TROUBLESHOOTING / Diagnosing Procedure
DIAGNOSING PROCEDURE
These six basic steps are essential for efficient
troubleshooting:
1. Study the System
Study the machine’s technical manuals. Know the
system and how it works, and what the
construction, functions and specifications of the
system components are.
2. Ask the operator
Before inspecting, get the full story of T4GB-05-01-001
malfunctions from the operator below.
(a) How is the machine being used? (Find out if
the machine is being operated correctly)
(b) When was the trouble noticed, and what
types of work the machine doing at that
time?
(c) What are the details of the trouble? Is the
trouble getting worse, or did it appear
suddenly for the first time?
(d) Did the machine have any other troubles
previously? If so, which parts were repaired
before?
3. Inspect the machine
Before starting the troubleshooting procedure,
check the machine’s daily maintenance points, as T4GB-05-01-002
shown in the operator's manual.
Also, check the electrical system, including the
batteries, as troubles in the electrical system
such as low battery voltage, loose connections
and blown fuses will result in malfunction of the
controllers, causing total operational failure of the
machine.
If troubleshooting is started without checking for
blown fuses, a wrong diagnosis may result,
wasting time. Check for blown fuses before
troubleshooting. Even if a fuse looks normal by
visual inspection, a fine crack is difficult to find.
Always use a tester when checking the fuses.
T4GB-05-01-003
T5-1-2
--- Page 11 ---
TROUBLESHOOTING / Component Layout
Right Console
1 2
3
4
5
6
7
9
8
M4FG-01-009
1 - Loader Control Lever 4 - Auxiliary 6 - eco Mode Switch 8 - Key Switch
2 - Auxiliary Control Lever 5 - Ride Control Switch 7 - Heater Switch (Optional) 9 - Loader Control Lever Lock
(Optional) (Optional)
3 - Auxiliary Control Lever
Lock (Optional)
T5-2-6
--- Page 12 ---
TROUBLESHOOTING / Troubleshooting A
HST CONTROL UNIT ERROR CODE LIST
Error Trouble Cause Influenced
Code Control
1-1 Abnormal start-up The supplied voltage to the HST control unit is HST pump
condition reduced. (10 V or less) control
The supplied voltage to the HST control unit is raised. HST motor
(17 V or more) control
Failure is diagnosed only when the HST control unit
starts.
2-1 Abnormal HST motor Faulty harness. HST motor
displacement angle Faulty proportional solenoid valve. control
control output
2-2 Abnormal HST pump Faulty harness. HST pump
displacement angle Faulty proportional solenoid valve. control
control output
2-3 Abnormal parking Faulty harness. Emergency
brake control output Faulty relay. parking brake
2-4 Abnormal Open circuit in harness of overrunning buzzer output. Buzzer control
overrunning buzzer Faulty overrunning buzzer. when overrunning
3-1 Abnormal speed The detected value is 60 km/h (37 mph) or more. HST motor
sensor Emergency stop of the detected value (The signal is control (100 %
stopped over 15 km/h (9 mph) or more when the HST output)
brake is depressed at 50 % or less in the operable
range.)
3-2 Abnormal engine The following abnormal values are detected. HST pump
speed sensor • Less than 300 min-1 when machine speed is 5 control (40 %
km/h (3 mph) or more. output)
• 0 min-1 when terminal L of the alternator is 12 V.
• Engine speed is beyond 5000 min-1.
3-3 Abnormal brake The sensor input voltage to the HST control unit is 0.25 HST pump
pedal angle sensor or less. control (50 %
low voltage output)
3-4 Abnormal brake The sensor input voltage to the HST control unit is 4.75 HST pump
pedal angle sensor or more. control (50 %
high voltage output)
3-5 Abnormal The following conditions are detected. Control selecting
forward/reverse lever • The forward and the reverse signals are detected forward and
at the same time. reverse travel
• Detected machine speed is below in sequence. operation
3 km/h (2 mph) with engine speed at 1500 min-1
or more without inputting the forward and the
reverse signal. → 0 km/h (0 mph)→ 3 km/h (2
mph) with engine speed at 1500 min-1 or more.
4-1 Abnormal low The supplied voltage to the HST control unit is 10 V or Normal operation
voltage less.
4-2 Abnormal high The supplied voltage to the HST control unit is 17 V or Normal operation
voltage more.
T5-3-2
--- Page 13 ---
TROUBLESHOOTING / Troubleshooting A
HST CONTORL UNIT ERROR CODE 3-2
Error Trouble Cause Influenced
Code Control
3-2 Abnormal engine The following abnormal values are detected. HST pump
speed sensor • Less than 300 min-1 when machine speed is 5 control (40 %
km/h (3 mph) or more. output)
• 0 min-1 when terminal L of the alternator is 12 V.
• Engine speed is beyond 5000 min-1.
YES
Replace engine speed sensor Disconnect connector of HST
with normal one and retry. control unit.
Check if error code disappears. Check for continuity between
YES terminal #37 of harness end
connector of HST control unit
and terminal #b of harness end
connector in engine speed
sensor.
Disconnect connector of engine
speed sensor.
Check if voltage between
ON terminals #a and #c of harness
end connector is 5V.
· Key switch: ON
Check if voltage between
terminal #a of harness end
connector in engine speed
ON sensor and body is 5±0.5V.
· Key switch: ON
Connector (Harness end of connector viewed from the
open end side)
Engine Speed Sensor Connector HST Control Unit Connector
a b c
T4FG-05-04-007
T4FG-05-04-001
T5-3-12
--- Page 15 ---
TROUBLESHOOTING / Troubleshooting B
Trouble symptoms 2. Hard to start engine
Fuel system
Incorrect of injection timing Wear of tappet, roller and cam
Injection starting pressure Faulty nozzle and nozzle holder
is too low.
Seizure in needle valve
Faulty spray pattern
Aging damage or breakage of nozzle
spring
Valve burnout
Engine unit
Seizure or wear in valve stem
Valve spring breakage
Compression pressure de- Faulty valve clearance
crease
Wear of cylinder, piston and piston ring
Sticking or breakage of piston ring
Blow-by of head gasket
Faulty engine control mechanism
Others
Faulty preheat system
T5-4-4
--- Page 16 ---
TROUBLESHOOTING / Troubleshooting B
TRAVEL SYSTEM TROUBLESHOOTING
Trouble symptoms A-1. The vehicle does not travel at all (traveling is impossible forward and reverse)
(1) Oil shortage in the hydraulic oil tank
Check for the hydraulic oil level.
1. Keep the machine horizontally.
2. Lower the bucket or the attachment onto the
ground horizontally.
3. Stop the engine. Check that the oil level of dip-
stick is between the upper limit mark and the
lower limit mark.
T4FG-05-02-001
Hydraulic oil Hydraulic oil amount
amount is short. is normal.
Repair oil leak area
and add oil.
M4EJ-07D-002
(2) Clogged suction strainer
Remove suction strainer (1) in the hydraulic oil tank.
Check for restrictions.
With restriction No restriction
1
Check HST filter element (2) 2 3
and hydraulic oil filter element T4FG-05-02-002
(3). Check for the foreign parti-
cles, which cause suction
strainer (1) restrictions.
Cleaning of suc- Repair of hydraulic Repair of hydraulic
tion strainer cylinders and hose pump
(Metal fragments (Nylon and rubber pieces)
included copper
powder)
T5-4-14
--- Page 17 ---
TROUBLESHOOTING / Troubleshooting B
Trouble symptoms A-4. Travel at engine low idle speed.
(1) Engine low idle speed is too high.
Measure the engine low idle speed.
1. Measure the engine low idle speed according to Engine Performance Test / Engine speed.
2. As for specification, refer to Operational Performance Standard.
Out of Specification Within Specification
1. The adjustment of accelerator linkage is faulty. Faulty bleeding air from HST circuit.
Even if the accelerator pedal is returned, the
pedal does not get in contact with the low idle
stopper in the governor.
2. Foreign objects get caught in the accelerator
pedal and the accelerator pedal is not returned
completely.
3. Rust and stuck of accelerator linkage.
(2) Faulty bleeding air from HST circuit
1. When the machine travels with the forward/reverse lever set in the Neutral position, perform the check
of hydraulic oil. (Especially pay attention to viscosity)
2. After the engine starts, when the machine travels with the forward/reverse lever set in the Neutral posi-
tion for a moment, bleed air from HST circuit.
Cause of trapping air is replacement of hydraulic oil filter or element, repair of motor or residual air
when replacing HST piping or hose. If any cause cannot be found, as air may be sucked from the
loosened part of HST piping and hose, check and retighten the hose and piping
T5-4-24
--- Page 18 ---
TROUBLESHOOTING / Troubleshooting B
BRAKE SYSTEM TROUBLESHOOTING
Trouble symptoms B-1. Brake control force decreases
(1) Leakage from the brake piping
Check oil amount in the brake oil tank in the master cylinder. If oil level is low, check for oil leaks from the
master cylinder and brake piping.
Brake oil shortage Normal
Oil leaks to the exterior is Oil leaks to the exterior is not
found. found.
Repair of oil leaks Add brake oil to specification. Mixing air in brake system
Add brake oil
Operate the service brake. Check oil amount in the brake oil tank.
Oil decrease Oil amount is normal.
Oil leaks in the reduction gear.
When there is no brake oil leaks to the exterior
completely and brake oil decreases at short
times, oil leaks may occur in the front axle.
1. Wear and damage of O-ring of the brake
piston and O-ring of the parking brake piston.
2. Wear and damage of piston sliding surface.
Replacement of O-ring or faulty parts
T5-4-34
--- Page 19 ---
TROUBLESHOOTING / Troubleshooting B
Trouble symptoms C-1. Steering operation is impossible or heavy
(3) Faulty steering valve (sticking or wear of spool and sleeve)
Measure the operating force of steering wheel.
1. Park the machine on a level paved road with traveling position. Release the parking brake.
2. Hydraulic oil temperature is kept at operating temperature (40 to 60 °C (104 to 140 °F)).
3. The bucket must be empty.
4. Measure the operating (rotational) force of steering wheel at engine low idle speed and fast idle speed
in this condition. At the same time, check for the unevenness (sticking) of operating (rotational) force.
As for specification, refer to Operational Performance Standard.
Measure the slip amount of steering wheel.
1. Turn the steering wheel to the right or left and get in contact with the frame stopper completely (stroke
end).
2. In addition, turning the steering wheel from this condition, the wheels rotate while slipping due to the
internal leaks of steering valve.
Measure the revolutions of steering wheel per 1 minute.
Specification
Specification on a new machine: 3.5 rev/min
When the slip amount of steering wheel reaches to 1.5 times or more, repair is required as the internal
leaks becomes excessive.
Out of Specification
Repair or replacement of steering valve
T5-4-44
--- Page 20 ---
TROUBLESHOOTING / Troubleshooting B
Trouble symptoms D-2. Cylinder drift of lift arm is large at the neutral position of control lever.
Measure the cylinder drift of lift arm.
When some complaints about “Lift arm is lowered at the Hold (Neutral) position of control valve” are re-
ceived, check if the lift arm drift amount is specification (normal) first.
1. Measure the hydraulic cylinder drift amount according to Operational Performance Test.
2. As for specification, refer to Operational Performance Standard.
The hydraulic cylinder drift amount is Within specification
considerably larger than specification.
Normal.
T5-4-54
--- Page 21 ---
TROUBLESHOOTING / Troubleshooting B
Trouble symptoms D-6. Bucket operation (tilt back) time is long or operation force is insufficient.
(5) All of measurement values in paragraph 1 to paragraph 3 of Measurement of Overload Relief Valve
Hydraulic Pressure are the same and lower than the main relief valve specification. In addition, meas-
urement value in paragraph 2 is specification.
Faulty or faulty adjustment of overload valve (3)
<Adjustment Methods>
(1) According to paragraph 3 of Measurement of Overload Relief Valve Hydraulic Pressure, hydraulic pres-
sure of overload relief valve (3) can be measured by using an oil pressure gauge.
(2) Loosen lock nut (6) of overload relief valve (3)
(3) While reading the needle of oil pressure gauge, turn adjusting screw * by using a hexagonal wrench so