ADVANCED TECHNICIANS COURSE CLUTCH SYSTEM

ADVANCED TECHNICIANS COURSE CLUTCH SYSTEM

1. ADVANCED
TECHNICIAN'S COURSE
3. CLUTCH SYSTEM
OVERSEAS SERVICE DEPARTMENT
HINO MOTORS, LTD

2. (1) Releasecylinder
This system converts oil
pressure, fed from the main
cylinder into mechanical force.
CONNECT DISCONNECT
RESERVE TANK
MASTER CYLINDER
CLUTCH PEDAL RELEASE CYLINDER
AIR TANK
RESERVE TANK
MASTER CYLINDER
CLUTCH PEDAL
CLUTCH BOOSTER
(COMPRESSED
AIR)
VACUUM TANK
CLUTCH BOOSTER(VACUUM)
CONNECT DISCONNECT
CONNECT DISCONNECT
MASTER CYLINDER
CLUTCH PEDAL
RESERVE TANK
1. Structure and Function
1) Clutch control system

3. (2)Master cylinder
RETURN SPRING
PUSH ROD PISTON
STOPER BOLT
RETURN SPRINGVALVE
Producing oil pressure and operating the release cylinder or
clutch booster.

4. (3)Clutch booster (vacuum servo)
DIAPHRAGM PLATE
VALVE SPRING
VALVE BODY
POPPET VALVE SPRING
POPPET VALVE ASSEMBRY
DIAPHRAGM ASSEMBLY
RELAY VALVE SPRING
DUST COVER
PUSH ROD
HYDORAULIC PISTON
CYLINDER BODY
FRONT CYLINDER SHELL
RETURN SPRING
DIAPHRAGM
REAR
CYLINDER
SHELL
POWER
PISTON
ASSEMBLY
PEDAL IS DEPRESSED
ATOMSPHERIC PRESSURE
PEDAL IS RELEASED
FROM MASTER
CYLINDER
TO VACUUM TANK
TO MASTER
CYLINDER
TO VACUUM TANK
The main part consists
of the three components
as the power cylinder,
control valve, and a
hydraulic cylinder.

5. (4)Clutch booster (air servo)
The main part consists of the same three components as the
vacuum servo type.
AIR BLEEDER
RELAY VALVE PISTON
POWER CYLINDER SECTION
CYLINDER SHELL
POWER PISTON
PUSH ROD
RETURN SPRING
FROM MASTER CYLINDER
HYDRAULIC CYLINDER SECTION
HYDRAULIC PISTON CUP
HYDRAULIC PISTON
SEAL RETAINER
EXHAUST PORT
DIAPHRAGM & STEM ADAPTER
RELAY VALVE SECTION
POPPET VALVE SPRING
RETURN SPRING
VENTILATION HOLE
COMPRESSED AIR
POPPET VALVE

6. EXHAUST
FROM AIR TANK
FROM CLUTCH MASTER CYLINDER
TO CLUTCH MASTER CYLINDER
ATMOSPHRIC PRESSURE
EXHAUST
COMPRESSED AIR
PEDAL IS DEPRESSED PEDAL IS RELEASED

7. CLUTCH FACING
CUSHION PLATE
CLUTCH PLATE
SPLINE HUB
DAMPER SPRING
Maintaining uniform contact with the flywheel and pressure
plate.
The friction face smoothly transmits torque -and at the same
time preventing deformation and damage to the clutch plate
itself.
The damper springs are designed to absorb and alleviate
impactwhen torque is suddenly transmitted from the rear axle.
2) Clutch disc

8. (1)Coil spring type
CLUTCH COVER
RELEASE LEVER
SUPPORT NUT
RELEASE BEARING
SHIFT BLOCK
RETURN SPRING
SHIFT FORK
CLUTCH SPRING
SPRING SEAT
PRESSURE PLATE
CLUTCH DISC
PILOT BEARING
FLYWHEEL
RETURN SPRING
Constantly transmitting force from the engine to the transmission.
Deformation against centrifugal force is prevented by the
spring guide.
3) Clutch unit

9. (2)Diaphragm spring type
CLUTCH COVER
DIAPHRAGM SPRING
SHIFT BLOCK
RETURN SPRING
SHIFT FORK
PRESSURE PLATE
FLYWHEEL
CLUTCH DISC
PILOT BEARING
The springs allow a variety of spring coefficients to be
obtained through the suitable selection of plate thickness and
height.

10. 2. Troubleshooting
Trouble Causes Chart
Clutch disc
Facing wear
Oil stuck to facing
Decreased friction coefficient due to heat
Clutch control
No play in the master cylinder
No play in release lever part
Faulty return (all control parts)
Riding the clutch
Frequent half-clutching
Driving-related causes
Pressure plate wear, damage, or deformation
Flywheel wear, damage, or deformation
Clutch spring deterioration
Clutch unit-related causes
Clutch slip
1. Clutch slip

11. Cause diagnosis
Clutch disc
Friction coefficient drop due to heat
The facing friction coefficient drops when the Ubun type facing
surface temperature rises.
Friction coefficient
Temperature (ºC)
Large
High
Wear Volume Versus Temperature (Example)

12. Large
Wear volume
High Temperature(ºC)
High
Wear Volume Versus Temperature (Example)
Furthermore, as the temperature increases, the amount
of facing wear also increases rapidly.

13. Trouble Causes Chart
2.Faulty declutching
Clutch control (fluid pressure/air
pressure-related causes)
Clutch unit-related causes Clutch disc-related causes
Faulty declutching
Clutch control
(mechanical causes)
Air mixed into clutch fluid
Faulty master cylinder cap seal
Faulty clutch booster cap seal
Faulty clutch booster air pressure
Faulty clutch booster air seal
Pedal height is too low
Excessive play in master cylinder part
Excessive play in release lever part
Faulty sliding of release bearing hub
Faulty pilot bearing
Excessive flywheel deformation
Excessive pressure plate deformation
Uneven release lever height
Excessive clutch disc vibration
Sticky clutch disc
Faulty spring sliding
Faulty conical shape

14. Inspection sheets
CLUTCH SLIPPING
CLUTCH-001
Chassis No: Country:
Engine No : TR. No :
NATURE OF DEFECT
1 When does the trouble occur?
(1) Start running Running at constant speed km/hr ml/hr
Shifting up from gear to gear
Shifting down from gear to gear
(2) With load Without load
1 Kind of clutch disk Semi mold Combination Ceramic
2 Does the driver put his foot on the clutch pedal?
Always Sometimes Only when sifting
3 Can the driver fully step on the clutch pedal? (Is driving seat position suitable)
Yes No
4 Does the driver take a long time for half clutch as compared with other drivers?
Yes No
5 Which gear is applied when the vehicle starts? gear
6 How is the operating power to disengage the clutch? Heavy Light
Please state if there is any difference compared to other vehicle
Maker Model Booster With Without
7 Adjustment of push rod play at top pedal mm in
INSPECTION ITEMS