Glossary “primary winding” Definition:
Low voltage windings of an ignition coil.

Glossary “primary seal” Definition:
Seal between the compressor shaft seal and the shaft to prevent the leakage of refrigerant and oil.

Glossary “primary shoe” Definition:
The brake shoe toward the front of the vehicle in a dual-servo drum brake having a lining that may be shorter, thinner, and have different frictional characteristics than that of the secondary shoe.

Glossary “primary surfacer” Definition:
A type of paint having a high solids content which fills small imperfections in body work and which usually must be sanded.

Glossary “primary trigger” Definition:
The electronic or electromechanical device that controls the switching of current flow in the primary windings.

Glossary “primary vibration” Definition:
When the piston slows down as it approaches TDC, its force puls the engine up. When it approaches BDC, it pulls the engine down.

Glossary “primary damage” Definition:
Damage caused by the initial impact of a collision.

Glossary “primary pump” Definition:
The vaned, concave metal shell in the torque converter which drives the turbine through fluid force. Also known as “impeller”.

Glossary “primary resistance” Definition:
Calibrated resistance wire or ballast resistor in a conventional ignition system inserted between the ignition switch and coil to reduce the primary voltage, after the engine has been started.

Glossary “primary circuit” Definition:
1). The electrical circuit of the low-voltage winding of the ignition coil. 2). The main fuel passages in a carburetor.

Glossary “primary colors” Definition:
Red, yellow, and blue.

Glossary “primary brake shoe” Definition:
Brake shoe in a set which initiates self-energizing action. Normally placed towards the front, and has less friction material.

Glossary “primary air suspension system” Definition:
Term used for a type of vehicle system that uses air, instead of coil, leaf, or torsion bar type springs, to support the vehicles weight.