Body CAN or Basic CAN

British Association old standard size of threads."

British Standards Kite Mark. The symbol of the British Standards Institute consisting of a triangle on its point with a capital B on its side above the triangle and a capital S inside the triangle.

British Standard Fine size of thread."

Battery Positive Voltage

An alloy of tin, copper, antimony and lead used as a coating for plain steel bearings.

A voltage produced that tends to oppose the voltage that created it.

(1) Non-rotating plate carrying the shoes of a drum brake. (2) Metal member carrying friction material of the disc brake pad.

The pressure build-up in the exhaust caused by the resistance to exhaust flow by pipe diameters and muffler baffles. Used in design to balance an exhaust to an engine.

Technique of sanding a surface to taper the paint film away from the metal repaired area.

Combustion of fuel in the intake or exhaust resulting in a loud explosive noise.

The base material of flatting paper onto which abrasive grains are coated. For masking tape, the backing is the paper section without the adhesive.

A supporting pad for abrasive disc and/or polishing pads that is attached to a polishing mop or a DA sander. In the compounding, glazing or polishing operation, a foam or wool polishing or glazing pad is attached on top of the backup pad. In dry sanding operations an abrasive disc is attached to the face of the pad.

The clearance between two components, usually used to measure the running clearance of gear teeth.

A second copy of work in case the original is damaged or destroyed. Should be stored away from the computer.

A part fitted behind the air cap in a spray gun to direct the air stream and reduce air turbulence.

Application of heat to cure and dry a coating. In automotive refinishing, baking is used to speed up the drying of air-drying finishes and is sometimes called force-drying. The metal temperature in refinish baking usually does not exceed 80°C (180°F).

A rotating shaft geared to another shaft, usually the crankshaft that carries counterbalance weights to bring the shafts into harmonic balance.

A hydraulic device that controls the pressure in different parts of a hydraulic circuit. Used to balance front and rear brake actuation.

Small weights used to balance a shaft or a wheel.

Additive used to balance colour formulae in proportion to size and pigment-to-binder ratio.

A component of a synchromesh gear hub that provides a cone clutch and guidance of the outer hub to the gear dog teeth.

A bearing consisting of inner and outer tracks with a series of ball bearings in between. A single surface hardened steel ball.

Flexible exhaust connection.

Joints that allow movement for suspension and steering.

A pivot that allows movement in several directions.

A simple valve that is closed off as a ball moves.

Electrical resistor used in low tension circuit to regulate ignition coil output when the engine is running and is by-passed during starting to give an increased spark voltage for cold starting.

The maximum amount of information (bits/second) that can be transmitted along a channel.

A hydraulic joint consisting of a hollow through bolt and a hose connector that looks like a banjo and from which it gets its name.

Measurement of pressure - one atmosphere.

Barometric Pressure

Air or gas pressure measured in a standard unit. (Pascal, psi, bar)

Used to help prevent skin damage when working, for example, with oils.

Terminal of a transistor that becomes conductive to the emitter when energised. The trigger terminal of transistors and thyristors.

A colour coat requiring final protection in the form of a sprayed clearcoat. The basecoat provides colour effects and appearance, while the clearcoat provides gloss as well as UV and chemical resistance.

Reading, writing, speaking in English (or Welsh) and using numbers sufficiently well to be able to function in society and at work. Key skills and basic skills overlap at levels 1 and 2.

Battery

An old type of combustion chamber looking like a bath tub when the cylinder head is turned over.

A chemical device that will give out an electrical current when connected into a circuit.

A tray to hold the battery, usually under the bonnet.

Petroleum jelly used on battery terminals.

A generic term meaning a collection of battery cells and control systems. Often relates to EVs or HEVs.

The main connections on a battery.

See Battery Post

A term used to describe the voltage of the particular system. This is often 12V - but could be 14V when the engine is running.

Body Control Module

Bottom dead centre. The position of the crankshaft when the piston is at its lowest position in the cylinder. The crankshaft is at 180° of rotation from the top dead centre 0° position.

Part of the tyre.

Type of non-independent suspension.

Equipment used to check the alignment of vehicle headlights.

Half-round parts that holds the big end and main bearings into place either on the con rods or engine block.

The freeplay between a bearing shell and journal.

Applies to the applied grip of a split shell bearing when the two halves are tightened together.

Components used to support a shaft and allow rotation.

Cover over the clutch assembly. Usually joins the gearbox to the engine.

A benign condition is one that is not usually serious or harmful. Zero emissions for example.

Hydrocarbon fuel additive and octane improver.

Gears cut at an angle from the periphery so that they can transmit a drive through an angle. An example is the final drive crown wheel and pinion.

Brake Horse Power

A spring made of two metals that expand differently with temperature change. This changes the tension as temperature changes.

Towards one side or one polarity.

Favouring one thing over another.

End of the con rod that fits to the crankshaft.

The journals and shell bearings on a crankshaft that carry the big ends of the connecting rods.

Two metals bonded together so that when heated, the different rates of expansion cause the strip to bend. The amount of bend is proportional to the temperature.

A spring that changes tension with temperature.

See Bi-metalic Valve.

A valve that operates when a temperature change moves a bimetal strip.

A system of numbering using 0 and 1 and used in computer operating systems.

An electronic device that counts in binary (1s and 0s) by using logic gates and basic memory devices.

A binary digit or bit is the basic unit of information in computing and telecommunications; it is the amount of information that can be stored by a device or other physical system that can normally exist in only two distinct states - 1 or 0, on or off for example.

The component in a paint material that forms the film. So-called because it binds the pigment and any additives present into a solid durable film.

Term used to describe one component sticking or rubbing against another.

The capacity of a material to decompose over time as a result of biological activity, especially to be broken down by microorganisms.

A binary digit or bit is the basic unit of information in computing and telecommunications; it is the amount of information that can be stored by a device or other physical system that can normally exist in only two distinct states - 1 or 0, on or off for example.

Equipment that records information about the performance of an aircraft during flight – or a vehicle during its normal use.

An electrical cable connector consisting of a blade and spring sided socket.

Screwed plugs used to blank off or block off a test port or adjustment point.

The act of removing air from a liquid system.

A small nipple valve that allows connection of a pipe and is operated by loosening.

A defect in which pigment from a lower coat of paint diffuses into an upper coat and discolours the latter. A non-bleeding colour is one that is not soluble in materials used over it and consequently does not work up into succeeding layers. Body filler may also cause bleeding if an excessive amount of hardener is added.

Repainting of panels or parts of panels and fading out the new colour onto adjacent prepared panel work to render the repair invisible. Normally only carried out on basecoat-and- clear finishes, as it is very difficult to blend a direct gloss paint finish.

Flaps used to mix hot/cold and fresh/recirculated air in a heater system.

Description of a 'quick press' of the throttle to make the engine rev up.

The development of hollow bubbles or water droplets in a paint film. Blistering is usually caused by the expansion of air or moisture trapped beneath the film. It can occur rapidly or any time after application as the paint film ages. Blistering may also occur from the presence of unreacted acid within the paint film.

A diagram of a system, in which the main parts or functions are represented by blocks connected by lines, which show the relationships between the blocks.

General term used to describe a bar that prevents an action of some kind.

A powder-like deposit which sometimes forms on the surface of a paint. It is often the result of a solvent component partly dissolving the pigment(s) and then depositing them on the surface when the temperature is below the 'dew point',( i.e. the temperature at which moisture will condense on the surface)

Ignition of fuel in the inlet manifold causing a flame to rise out of the air intake through the carburettor.

A motor that uses a fan to assist in moving air.

Wireless Technology. A chip is responsible for the transmission of data between a wide range of devices (mobile phone and hands-free system) through short range digital two-way radio.

Trade name for 'blue' headlight bulbs produced by Philips.

The appearance of whitish or "cloudy" areas in a paint finish, caused by absorption and retention of moisture in a drying paint film.

Barometric/Manifold Absolute Pressure Sensor

Main portion of motor car.

A heavy-bodied 2K plastic filler material which cures very hard and is used to fill small dents in metal and plastic panel work.

Thickening of paint in the can, usually due to evaporation of solvents or volatile material because of poor fitting lids or exposure to heat or air.

Attraction between two things such as to cause them to stick together.

Cables or wires used to connect different panels together.

Adhesive often used on friction linings.

Brake on/off switch

The amount of increase above atmospheric pressure provided by a supercharger.

See blower motor.

Usually made of rubber, a cover for a moving component such as a track rod end.

A rubber (or similar) boot used to cover working components. It is used to keep dirt out and in some cases lubrication in place. Also slang for alligator...

The internal part of a hollow cylinder in which a piston is located.

Used to cut cylinder bores.

Boron steels possess hardenability equivalent to that of much higher carbon steels and more expensive low alloy heat treatable steels. Tempering toughens boron steels. The addition of only 0.001-0.003% soluble boron to a suitably protected base steel can produce an increased hardenability compared other steels.

Robert Bosch GmbH is a technology-based corporation which was founded by Robert Bosch in Stuttgart, Germany in 1886.

A reinforcing section around a cylindrical bore in a component.

The position of the crankshaft when the piston is at its lowest position in the cylinder.

Vehicle body suspension movement when hitting bumps.

A manual test of suspension dampers (shock absorbers) by pushing down on the suspension and observing the oscillations when released.

Movement of an electric window as it hits an obstruction - and bounces back (opens again).

This form of lubrication is essentially a breakdown of hydrodynamic action. At high loads or low speeds, the pressure of the oil film cannot prevent metal-to-metal contact. So the opposing surfaces partially ride on an oil film and partially rub together as surface high points come in contact. Lubrication is provided by lubricant decomposition products or surface-active additives which form a thin, soft, solid film on the metal surfaces and prevent metal-junction adhesion.

A U shaped tube used to measure vacuum.

Parts of the vehicle body - chassis and structural members.

A horizontally opposed engine.

A barometric pressure sensor.

Back pressure Sensor

Back Pressure Transducer

(1) Device to retard the motion of a vehicle or to prevent inadvertent movement when parked. (2) Dynamometer for measuring the power of an engine, originally a friction brake by which torque could be measured. Also brake dynamometer (informal).

A pressure container fitted into pumped hydraulic systems to maintain a reserve of pressure if the pump fails. They also smooth out the pump pulses in the system.

A mechanical device for taking up the free play in brake components. Can be either manually or automatically operated.

The splitting of brake effort to each axle in relation to the optimum that the axle can provide.

A friction material lined strap around a epicyclic gear annulus. Operated by hydraulic pressure to hold the annulus for gear ratio selection.

See brake servo.

The fixed component of a disc brake holding the pistons that apply an inward force to press the brake pads onto the rotor.

The wheel cylinders of hydraulic brakes in the brake unit.

Rotating drum inside which brake shoes operate.

Reduction of braking effort resulting from overheating of friction surfaces, or other transient effect.

A special liquid used in hydraulic brake systems. Always check data because some types should not be mixed.

A measure of the power output from an engine when measured with a dynamometer using a brake applied to the engine flywheel. The engine effort to overcome the braking force gives the bhp value.

The hydraulic pipes and hoses of the brake system.

The friction material attached to brake shoes and pads.

A general term to describe components that link different parts of the brake system together.

A steel plate with a bonded friction lining used on disc brakes. Similar to the brake shoe of a drum brake.

Rollers used to drive the wheels of a vehicle for brake testing purposes.

A mechanism (vacuum or hydraulic) that increases the braking effort applied by the driver.

Part of drum brake carrying linings.

The force applied to the brakes.

Forces that are caused by braking.

A terminal box for carrying out diagnostic tasks on electrical and electronic systems.

A type of rectifier using four or more diodes to give full wave rectification.

A characteristic of undercoat performance that occurs when a scratch or surface imperfection is not completely filled, leaving a cavity underneath. It i caused by under-reducing the primer or using too fast a solvent and can lead to the appearance of sand scratches in the finished repair.

The formation of a metallic-appearing haze on a paint film.

A plate used to hold brushes in contact with a commutator.

Pieces of carbon or metal ending in wires or strips. Contacts onto rotating slip-rings or generator/motor commutators.

Before Top Dead Centre

BTDC - Before Top Dead Centre.

The position of the crankshaft before the piston has passed the top of the cylinder and is still on the way up.

British Thermal Units

A technique used to polish an area to remove sanding marks or surface imperfections (see Polishing).

Soft paste containing various grades of fine abrasives suspended in a neutral medium, used to eliminate fine scratches and polish the topcoat.

The amount of paint film deposited on a substrate (the depth or thickness of which is measured in microns).

Substantial structural panel of vehicle body in front of passenger compartment. Also known as a firewall.

A hard hat.

Steering action that results from hitting a bump.

A rubber spring that limits and dampens the movement of a spring to prevent excessive deflection and spring damage.

The ability to float in liquid or in air.

Term used to describe rough edges on metal components.

Cylindrical sleeve forming a bearing surface for a shaft or pin.

A metal and rubber composite bearing that provide both a limited range of movement and insulation from road vibration.

A conductor in a fuse box or other electrical distribution device.

Synthetic rubber impervious to oxygen.

A medium-evaporating solvent used in paint.

A secondary route in a system that allows gas, liquid or electricity to flow outside of the main route.

In a lubrication system a valve that allows oil to bypass a filter.