What is pressure?

pressure test

Glossary “pressure test” Definition:
Procedure for testing the entire cooling system for leaks. Or, a test to tell if the A/T is experiencing internal leakage or requires adjustment to the linkage or vacuum modulator. May also refer to the pressure applied to an evaporative emission system to check for leaks. This would be used to perform an evaporative system integrity test.

pressure tester

Glossary “pressure tester” Definition:
Device used to pressure test the cooling system and pressure cap. Can also refer to any piece of equipment that is used to externally apply a pressure to a system, for the purpose of testing its integrity.

pressure regulator

Glossary “pressure regulator” Definition:
1). Device that operates to prevent excess pressure buildup in a system. 2). A valve in some automatic transmissions that opens to release oil from a line when the oil pressure reaches a specific maximum limit.

pressure relief valve

Glossary “pressure relief valve” Definition:
1). A valve held closed by a spring or other means, which automatically relieves pressure in excess of its setting. 2). Carburetor fuel bowl vent operated by vapor pressure from evaporated fuel. 3). AIR system valve that functions to relieve pump-output pressure that exceeds a predetermined amount. 4). Valve in an engine oil pump having a calibrated spring working against a moveable plunger or ball to regulate maximum oil pressure.

pressure plate assembly

Glossary “pressure plate assembly” Definition:
An assembly of various parts that operate to “press” the clutch disc against the flywheel, engaging power flow to the input shaft, or “release” the disc, disengaging power flow.

pressure line

Glossary “pressure line” Definition:
1). Term that generally refers to the discharge line of an air-conditioning system. 2). Term that may apply to brake or power-steering hoses.

pressure plate

Glossary “pressure plate” Definition:
Part of a manual clutch that is mounted on and rotates with the flywheel and exerts pressure against the friction disk. Also found in A/T clutch packs, used to apply force to the fiction clutches.

pressure hold

Glossary “pressure hold” Definition:
Condition in an ABS control module in which no more braking pressure is applied to a brake circuit, because the module senses a wheel lock-up condition.