PRESSURE RELIEF VALVE GROUP 7S4327 - Caterpillar

Introduction
When the words "use again" are in the description, the specification given can be used to determine if a part can be used again. If the part is equal to or within the specification given, use the part again.When the word "permissible" is in the description, the specification given is the "maximum or minimum" tolerance permitted before adjustment, repair and/or new parts are needed.A comparison can be made between the measurements of a worn part and the specifications of a new part to find the amount of wear. A part that is worn can be safe to use if an estimate of the remainder of its service life is good. If a short service life is expected, replace the part.Electrical System
Wiring Diagrams
Pilot Panel Wiring Schematic (3116 & 3126 Engines) Engine and Junction Box (3116 Engine)
Wiring Diagram Notes
Only one fuel shutoff solenoid will be installed on the engine. Only the wires for the installed solenoid will be provided.Component shown dashed is located in the junction box.
Junction Box Diagram (3116 Engine 7E1330 Wiring Diagram)
Engine Diagram (3116 Engine 7E1330 Wiring Diagram)
Engine Diagram (3116 Engine 113-1100 Wiring Diagram)
Junction Box Diagram (3116 Engine 113-1100 Wiring Diagram)Engine and Junction Box (3126 Engine)
Wiring Diagram Notes
Only one fuel shutoff solenoid will be installed on the engine. Only the wires for the installed solenoid will be provided.Component shown dashed is located in the junction box.
Junction Box Diagram (3126 Engine)
Engine Diagram (3126 Engine)Components
Water Temperature Contactor
A water temperature contactor switch is located in the cooling system. This unit is non-adjustable. Thermal expansion of the element operates a micro-switch that signals an alarm on the pilot panel. The water temperature element must be in contact with the coolant. After an overheated engine is allowed to cool, the contactor automatically resets itself.Oil Pressure Switch
An oil pressure switch is located in the oil system. This switch has three terminals and serves a dual purpose. One use of this switch is to power the hour meter after the engine oil pressure reaches normal operating pressure. The other use is to signal an alarm on the pilot panel when engine oil pressure drops below the desired oil pressure.Control Relay
This is a standard type relay that, when energized, has contacts that open across one circuit and close across another circuit. The circuits are wired so that when the relay is energized voltage from the battery will go to and energize the fuel shutoff solenoid (on engines equipped with an energize to run type of solenoid). On engines which use a latching type (energize to shutoff) fuel solenoid, the control relay is de energized and voltage flows from the battery to the STOP terminal on the fuel shutoff solenoid. This in turn shuts down the engine.Electrical Indicators And Sending Units
The electrical indicators and sending units operate in electrical balance. Because of this, the voltage and resistance ratings are important to get the correct indications on the indicators.Water Temperature Sending Unit
Sending Unit for Water Temperature
(1) Bulb. (2) Nut. (3) Connection.The sending unit for water temperature is an