Clutch (Description): Description and operation

Description

Clutch System Description

The clutch system is a conventional diaphragm type clutch operated by a hydraulic master cylinder. The hydraulic system is manufactured from plastic. The system is sealed for life and can only be replaced in its entirety. The clutch requires no adjustment to compensate for clutch drive plate wear.

Hydraulic Clutch – K1.8 Engines

The hydraulic clutch comprises a master cylinder and a slave cylinder connected by a one piece plastic tube. The system comes as a complete assembly, pre-filled with hydraulic fluid to ease replacement and minimize repair times. The master and slave cylinders are manufactured from injection moulded thermoplastic which can operate in extremes of temperatures.

The master cylinder is located in the bulkhead in a specially designed hole which allows the cylinder to be installed at a 45° angle from vertical. Once located, the master cylinder is rotated to the vertical position and is automatically secured in this position. The master cylinder has a piston which moves in the cylinder. A rod is attached to the piston and to a spigot on the clutch pedal. A fluid reservoir is mounted on the engine compartment side of the master cylinder and is sealed with a removable rubber cap.

A nylon tube is connected to the master cylinder by a swivel coupling which aids installation and alignment. The other end of the tube is connected to the slave cylinder, also using a swivel coupling. The nylon tube is flexible to allow ease of routing and absorbs engine movements and vibrations.

The slave cylinder comprises a cylinder with a piston and rod. The piston rod is fully extended when the clutch pedal is depressed and almost fully retracted when the pedal is at rest.

A new slave cylinder has the piston locked in the retracted position by a plastic clip. When the clutch is first operated, the hydraulic action of the clutch system breaks the plastic clip and allows the rod to extend. Care should be taken to ensure that the rod is correctly located in the release arm after the first operation of the clutch pedal. The plastic clip locates in a spherical seat in the release lever. The slave cylinder is attached to a bracket which is bolted to the gearbox. A specially shaped slot in the bracket locates the slave cylinder and a plastic clip secures it in position.

Hydraulic Clutch – Td4 Engines

The hydraulic clutch comprises a master cylinder and a slave cylinder/hydraulic release bearing connected by a two piece plastic tube. The system is supplied as a two piece system, pre-filled with hydraulic fluid to ease replacement and minimize repair times. The master cylinder is manufactured from injection moulded thermoplastic which can operate in extremes of temperatures.

The master cylinder is located in the bulkhead in a specially designed hole which allows the cylinder to be installed at a 45° angle from vertical. Once located, the master cylinder is rotated to the vertical position and is automatically secured in this position. The master cylinder has a piston which moves in the cylinder. A rod is attached to the piston and to a spigot on the clutch pedal. A fluid reservoir is mounted on the engine compartment side of the master cylinder and is sealed with a removable rubber cap.

A nylon tube is connected to the master cylinder by a swivel coupling which aids installation and alignment. The tube is fitted with a self sealing, quick fit coupling which mates with a similar connection on the slave cylinder tube.

The slave cylinder is located inside the clutch housing and is integral with the release bearing. The assembly is located and supported on a tube which is fitted over the gearbox input shaft. The pipe from the slave cylinder passes through a sealing grommet in the gearbox clutch housing and is terminated with a self sealing, quick fit coupling, which mates with the coupling on the pipe connecting the master cylinder. A second pipe is also attached to the slave cylinder and emerges from the sealing grommet and is terminated with a bleed nipple.

A coil spring is located between the piston of the slave cylinder and the release bearing. The spring holds the release bearing against the pressure plate diaphragm.