Schedule Service
Auto Glossary
AAA
Acronym for American Automobile Association
Backfire
Passage of unburned fuel mixture into the Exhaust system where it is ignited and causes an Explosion (backfire) prematurely.
Sometimes Ignition takes place in the Intake manifold by a flame from a Cylinder because the Intake valve leaks. Burning of the fuel mixture in the Intake manifold may be caused by faulty Timing, crossed plug wires, leaky Intake valve, etc.
A welding term referring to a short pop of the torch flame followed by extinguishing of the flame or continued burning of the gasses.
Backfiring
Repeated backfires in the exhaust or the cylinders.
Backflushing
Pushing fluid in a direction opposite of normal flow. This is done for cleaning the engine's cooling system
Back pressure
The Resistance to the flow of Exhaust gases through the Exhaust system. By rerouting the exhaust gases for noise suppression, a Muffler causes back pressure, but a straight pipe alone causes only minimal back pressure. Some engines require back pressure, so that removing the Exhaust system will cause internal damage.
Pressure in low side of refrigerating systems; also called suction pressure or low-side pressure.
The pressure opposing the motion of the piston of an engine on its exhaust stroke.
The exhaust pressure of a turbine. Increased by clogged or defective exhaust system.
Pressure against which a fluid or gas is flowing, resulting from friction in lines, restrictions in pipes, valves, pressure in vessel to which fluid is flowing, hydrostatic head, or other impediment that causes resistance to fluid flow.
Ball Joint
A flexible Joint using a ball and Socket type of construction, used in Steering linkage setups, Steering knuckle pivot supports, etc. Their flexibility helps to compensate for the changes in the wheel and steering when turning or hitting a bump on the road. There are usually upper and lower ball joints attached to the upper and lower A-arms. Some have a grease nipple to allow periodic lubrication. 
Carburetor
(Carb) Optionally spelled carburetter or carburettor. A device that Vaporizes fuel and mixes it with air in proper quantities and proportions to suit the varying needs of the engine. A Filter screens the air which is drawn into the carburetor. Here the Gasoline mixes with the air and this fuel vapor enters the Combustion chamber through the Intake valve where it is compressed and burned.
Carburetor kit
A collection of gaskets, O-rings, jets, etc. to rebuild a carburetor. Also called a carb kit.
Cardan joint
Cardan Joint
A type of Universal joint named after the Italian Cardan who developed the concept in the 16th century. In the 17th century, Robert Hooke of England developed and patented the conventional universal joint. Sometimes it is called the Cardan universal or the Hooke universal. It has two Yokes at right angles to each other.
CARS
Acronym for Canadian Automotive Repair and Service Council
Catalyst
A substance that changes the rate of a chemical reaction without itself being used up. Catalysts are used in many processes in the chemical and petroleum industries. Emission control catalysts are used to promote reactions that change exhaust pollutants from internal combustion engines into harmless substances. After the reaction it can potentially be recovered from the reaction mixture chemically unchanged.
A special agent which is added to a plastic body filler or resin or paint to speed up the hardening process.
Catalytic converter
A pollution-control device found on the Exhaust system of all cars since its introduction in 1974 which acts like an Afterburner to reburn unburned gas in the Tail pipe. It looks like a small Muffler and is usually made of stainless steel. It contains Platinum, rhodium, or palladium which is a catalyst for the chemical reaction needed to burn off any unburned Hydrocarbons and Carbon monoxide by turning them into water vapor, carbon dioxide and other less toxic gases.
A device containing a Catalyst for converting automobile exhaust into mostly harmless products.
Daytime running lights
(DRLs) A safety-oriented lighting system in which the headlights or other front lights are constantly on even during the day. They help to prevent possible accidents because oncoming traffic can be seen. December 1, 1989, Canada became the second country after Norway to require daytime running lights on all new passenger vehicles. In other countries the implementation of DRLs has had mixed response.
Fabricate
To make, usually by a relatively complex process or from several parts
Fan belt
A flexible rubber belt that connects various Components in the engine compartment, i.e., Alternator, Water pump, Emission controls, Power steering pump, and Air conditioner Compressor. Also called Drive belt or Serpentine belt
Fan clutch
A Viscous (fluid) drive coupling device connected to the center of the fan to permit variable engine fan speeds in relation to engine speeds. The Clutch engages and disengages the fan according to the engine temperature through a thermostat
Galvanize
The action of plating with zinc and/or lead by hot dipping or Electrodeposition to protect from rust.
Gap
The distance between the center terminal (Electrode) and the outer terminal (Electrode) through which the Spark must travel in a Spark plug.

Gas cap
A vented covering on the top of the tube leading to the fuel tank. Also called fuel cap
Gas filter
A device for screening the Gasoline to remove the impurities.
Gasket
A material made of Asbestos, cardboard, cork, paper, rubber, or soft metal placed between two metal parts to insure proper sealing.
Gasoline
A Hydrocarbon fuel used in an Internal combustion engine. Gasoline is refined from crude oil which is made up of fossilized plant and animal remains. In Britain it is called petrol.
Gas shock absorber
A gas-assisted shock absorber
Halogen bulb
A bulb containing a trace of a halogen, such as iodine. A halogen bulb gives off a brighter light.
Handbrake warning light
A light on the instrument panel that illuminates when the handbrake is applied; on most new cars it has been superseded by a multifunction brake warning light
Harmonic balancer
Also called Vibration damper. It usually is a solid Crankshaft Fan belt Pulley that has a weight ring bonded by rubber to the inner crankshaft-mounted ring. The outer ring absorbs and cancels out Crankshaft vibrations that otherwise might cause the Crankshaft to break. Formerly, two gearwheels carrying an unbalanced weight, mounted in bearings below the middle main crankshaft bearing, driven at twice engine speed and rotating in opposite directions to counterbalance the secondary vibrations in a four-cylinder reciprocating engine.
Hazard flasher switch
A switch (usually located on the steering column below the steering wheel) which makes all the signal lights flash simultaneously, to warn other vehicles that your car is disabled or going very slowly down the road. Also called 4-way warning light switch.
IAC
Acronym for Idle air control valve
Jake brake
A device which shuts off the Exhaust valves manually so that in the Exhaust stroke, the burned gasses cannot escape through the Exhaust valves. Instead they press against the Head of the piston and causes the Piston to slow down. When the Intake valve opens, some of the exhaust escapes out the intake valve and gives a distinctive loud rapping noise. Jake brakes are used in large truck engines to assist in slowing the vehicle. Many municipal bylaws prohibit the use of jake brakes because of the excessive noise. The most common type is called a Jake Brake because the predominant manufacturer is Jacobs Vehicle Equipment Co. Other types of retarders include exhaust retarders, transmission-mounted hydraulic retarders and axle-mounted electromagnetic retarders. Also called a retarder.
Lash
The amount of free motion between two components (e.g., two gears). The British term is free play.
Acronym for Lighter Aboard Ship a ship designed to carry floating containers or Lighters.
Latch
A fastening device for a door or panel. It consists of a small metal bar, either mounted on the movable part (always on doors and on some tailgates), or on the car body (always on hoods and trunks), which engages with a striker on the opposite part.
MAF
Acronym for Mass airflow meter. A sensor used to measure the amount of intake air entering the engine on some fuel injection systems
Magnaflux
A special chemical process, used to check parts for cracks.
A magnetic method of determining surface and subsurface defects in metals.
Main bearings
The bearings in the engine block that support the Crankshaft.
Manifold
A pipe or number of pipes connecting a series of holes or outlets to a common opening.
A device which controls refrigerant flow for system test purposes by means of hand valves which can open or close various passageways connected together inside the manifold. Used in conjunction with manifold gauges and service hoses
The conduit of an Appliance that supplies gas to the individual burner.
Manifold absolute pressure sensor (MAP)
A sensor which monitors the engine's intake manifold pressure and transmits the data to the engine controller. A pressure-sensitive disk capacitor used to measure air pressure inside the intake manifold. The Map sensor sends a signal to the computer which uses this information to determine load conditions so it can adjust spark timing and fuel mixture. Also called Manifold pressure sensor or Pressure differential sensor
A sensor that measures absolute air pressure in the intake manifold.
Manual choke
A Linkage system which begins with a knob on the Dash which can be pulled to activate and pushed to de-activate. The knob is attached to a cable and the other end of the cable is attached to a the Butterfly valve on the Carburetor. Because many Drivers had difficulty knowing when to use the choke knob, manufacturers developed the Automatic choke system which decides this information for the Driver.
Manual transmission
(MT or M/T) A Transmission system in which gears are selected by the Driver by means of a hand-operated Gearshift and a foot-operated Clutch. In a Motorcycle the Clutch is hand-operated and the gearshift is foot-operated. Contrasts with an Automatic transmission. Also called a standard transmission.
MAP
Acronym for Manifold absolute pressure
Acronym for manifold air pressure sensor
Marker lamp
A light which is mounted on the extreme edges of the roof of a truck to show the maximum height and width of a vehicle. Also called clearance lamp.
Master cylinder
The primary component for pressurizing fluid in a hydraulic system. Used in the braking system, it supports a reservoir for holding brake fluid and is activated each time the driver depresses the brake pedal.
The device that converts mechanical pressure from the brake pedal into hydraulic pressure that is routed to the wheels to operate the friction assemblies.
N2O
Short for nitrous oxide
NADA
Acronym for National Automobile Dealers Association
NADA Used Car Guid
A listing of current car prices, based on age, condition, and optional equipment; published by National Automobile Dealers Association
O2 sensor
A device that detects the amount of oxygen in the exhaust stream and sends that information the ECM. Also called an Oxygen sensor or an Exhaust oxygen sensor
Parking brake
Hand or foot operated brake which prevents vehicle movement while parked by locking rear wheels, or Transmission Output shaft. One type applies the rear Brake shoes by mechanical means and the other type applies a Brake band to a Brake drum installed in the Drivetrain.
The secondary brake system used to hold a stationary vehicle from moving. The system is applied with a hand or foot lever, and operates on only two wheels.
The mechanically actuated portion of a drum brake or disc brake caliper, used to prevent the vehicle from rolling when it is parked, applied by a lever, pedal, or rod
Parking lamp
An energy-saving vehicle illumination mode on British cars for long-term roadside parking; includes only one front sidelight and one taillight; the parking light can be switched to illuminate the left side or the right side
Park safety switch
A switch which allows the starter to be engaged only when the automatic shift lever is in either park or neutral
R-12
(dichlorodifluoromethane) Popular refrigerant known as Freon 12.
RABS
Acronym for Rear-wheel Anti-lock Brake System (Ford)

Rack and pinion gearbox
A type of Steering system with a Pinion gear on the end of the Steering shaft. The pinion engages a long rack (a bar with a row of teeth cut along one edge). When the Steering wheel is turned, the pinion turns and moves the rack to the left or right. This movement is carried through Tie rods to the Steering arms at the wheels.

Rack and pinion steering
The pinion gear rotates with the steering shaft, moving the rack from side to side. Several full turns of the pinion are required to shift the rack from lock to lock. Because there are so few parts in the steering linkage, rack and pinion is a very precise and responsive steering system and is often used in sports cars.
Radiator
A device that cools the liquid in the Cooling system by allowing it to circulate through a series of water Channels, which are exposed to air Ducts.

Radiator drain cock
A radiator tap; unlike the Radiator drain plug, tools are not required to drain the coolant from a radiator with a drain cock.
Radiator hose
The rubber pipe connecting the radiator to the cylinder block.
Radiator overflow tank
A small bottle that acts as a reservoir for liquid expelled from the Cooling system through the Overflow pipe and returns the liquid to the system when it cools down. A special Radiator Pressure cap is also part of the kit. It is also called a Closed Cooling System when it is part of the Original equipment.
Radius arm
An additional suspension link in a beam axle layout providing fore-and-aft location of the axle.
Ratio
A fixed relationship between things in number, quantity or degree. For example, if the fuel mixture contains one part of gas for fifteen parts of air, the ratio would be 15 to 1.
Sagging door
A door that sits too low in the door opening which is often indicated by an uneven door gap that widens towards the rear bottom and front top of the door but narrows down at the rear top and front bottom. This condition may be caused by faulty setting of the door hinges and lock/striker assembly. On convertibles, it often pinpoints structural damage, because the chassis may be bending in the middle
Tachometer, (tach)
1. A device used to indicate the speed of the engine in rpm. The tachometer is mounted on or near the Dashboard (some even appear on the Hood and others in a heads-up display on the Windshield). It helps the Driver to know the optimum rpm for changing gears on a vehicle with Manual transmission. A tachometer is also a diagnostic device which a mechanic uses to determine Idle speed and other Carburetor and running settings. Also called a rev counter.
2. A small generator normally used as a velocity-sensing device. Tachometers are typically attached to the output shaft of DC servo motors requiring close speed regulation. The tachometer feeds its signal to a control which adjusts its output to the DC motor accordingly (called closed loop feedback control)