DESCRIPTION
The pump (1) is connected to the steering gear (2) via the pressure hose (3) and the return hoses (4). The pump shaft has a pressed-on pulley (6) that is belt driven by the crankshaft pulley.
Scheme 7
5.7L engines have the power steering pressure switch (8) located in the pressure hose (3). 3.7L & 4.7L do not have a power steering pressure switch. The power steering oil cooler (5) is mounted to the front lower part of the radiator (7).
Note. Power steering pumps are not interchangeable with pumps installed on other vehicles.
Scheme 8
OPERATION
Hydraulic pressure is provided for the power steering gear by the belt driven power steering pump. The power steering pumps are constant flow rate and displacement, vane-type pumps.
Scheme 9
The recommended fluid for the power steering system is Mopar(R) ATF +4.
Mopar(R) ATF +4, when new is red in color. The ATF +4 is dyed red so it can be identified from other fluids used in the vehicle such as engine oil or antifreeze. The red color is not permanent and is not an indicator of fluid condition, As the vehicle is driven, the ATF +4 will begin to look darker in color and may eventually become brown. THIS IS NORMAL . ATF+4 also has a unique odor that may change with age. Consequently, odor and color cannot be used to indicate the fluid condition or the need for a fluid change.
A pressure sensing switch (8) is included in the power steering system (mounted on the high-pressure line (3) ). This switch will be used only on vehicles equipped with a 5.7L V-8 engine and power steering.
Scheme 10
The power steering pressure switch provides an input to the Powertrain Control Module (PCM). This input is provided during periods of high pump load and low engine rpm; such as during parking maneuvers. The PCM will then increase the idle speed through the Idle Air Control (IAC) motor. This is done to prevent the engine from stalling under the increased load.
When steering pump pressure exceeds 2413 kPa +/- 862 kPa (350 psi +/-125 psi), the Normally Closed (NC) switch will open and the PCM will increase the engine idle speed. This will prevent the engine from stalling.
When pump pressure drops to approximately 3965 kPa (575 psi), the switch circuit will re-close and engine idle speed will return to its previous setting.