- P -

Parking-brake System

A brake system, intended to hold a vehicle stationary, in which one or more brakes may be held in the applied position without continued application of force to the control.

Part Number (PN)

The alphanumeric designating a part as listed in a catalog or parts list.

Part Out

To sell an assembly, such as an engine, piece by piece.

Particle

A very small piece of dirt, metal or other debris which can be contained in oil, air, or fuel that can be removed with a filter.

Particulate

1. A solid matter, mainly soot from burned carbon, in an internal combustion engine's exhaust. 2. A form of solid air pollution such as microscopic solid or liquid matter that floats in the air.

Particulate Emissions

Solid particles, such as carbon and lead, found in vehicle exhaust soot. A problem, especially in diesels.

Particulate Trap

An emissions control device in the exhaust system of a diesel engine which is used to capture particulate before they can enter the atmosphere.

Parting Edge

The excess flash material that is found around the edge of a part that has been cast in a two-piece mold.

Partition Coefficient

The ratio of the solubility of a chemical in water as compared to its solubility in oil.

Partitions

Separations between the cells of a battery.

Parts Changer

One who, without proper diagnostic skills, randomly changes parts until the remedy to a problem is found.

Parts Chaser

1. A vehicle used for errands. 2. A person who runs errands, especially for buying parts.

Parts Counterman

One very knowledgeable in part numbers, and/or determining requirements who generally works in a parts-supply wholesale ore retail outlet.

Parts Distribution

A wholesale, discount, or retail establishment that sells parts to the trade or do-it-yourselfer.

Parts Manager

One responsible for ensuring that the in-house stock of parts is adequate so the customer's parts are readily available to the service technician when needed.

Parts Per Million (ppm)

1. A unit used to measure the amount of contamination in a substance, such as moisture in refrigerant. 2. A measurement of the emissions of a motor vehicle given as the number of parts of a particular chemical within one million parts of exhaust gas.

Parts Requisition

A form that is used to order parts.

Parts Specialist

One who sells automotive engine and vehicle parts.

Parts Washer

A machine that is used to clean parts.

PAS

Pulse air system.