VALVE GP-RELIEF 6E2914 - Caterpillar

Introduction
This Special Instruction contains the necessary procedures and information for the repair of 3400 engines after a cylinder head gasket failure. Proper repair procedures will increase the longevity of a head to block joint repair. The omission of any of the steps from the procedure could reduce the useful service life of the new cylinder head gasket.In addition to the steps outlined in this special instruction, correct calibration and operation of other components/systems should be verified. These can include:* Ether Starting Aids* Timing Advance* Governor Rack/Torque Settings* Water Pump Output/Thermostat Operation* Radiator/Oil Cooler Flow - Winter Fronts* Intake/Exhaust System Restriction LevelsThese components affect the cylinder pressure and thermal stress to which the head gasket is subjected. Improper calibration and operation will adversely affect the life of the head to block joint repair. Refer to the service manual for operations not covered in this special instruction. Two videos are available to provide additional information on testing and repair procedures. Refer to LEVN2245, "Detection of Air Combustion Gases in the Cooling System" and LEVN2361, "Head to Block Joint Repair". Refer to the guidelines for reusable parts for other criteria on component reuse not covered in this publication.Reference: Engine Data Sheet, LEKQ7235. Guideline For Reusable Parts, SEBF8131, "Spacer Plates", SEBF8068, "Cylinder Liners", and SEBF8198, "Procedure to Install Top Deck Insert in 3406 Remanufactured Engines or Short Blocks". Special Instructions, SMHS8222, "Installation of 2W-3815 or 5N-0093 Inserts". Video, LEVN2245, "Detection of Air and Combustion Gases in the Cooling System" and LEVN2361, "Head to Block Joint Repair".Required Tooling
Combustion Gas Leakage Tests
Refer to video LEVN2245, "Detection of Air Combustion Gases in the Cooling System". Coolant loss and aeration can be caused by reasons other than combustion gas leakage past the head gasket fire ring seal.Air can enter the system by:* Filling the system improperly.* Allowing the coolant level to drop too low.* Improper cooling system maintenance.* Venting the system improperly.* Through a cracked air compressor head.Combustion gases can enter the cooling system at:* The head to block joint.* An injector adapter/seal.* A cracked cylinder head.* A cracked cylinder liner flange.* Through a pitted cylinder liner.One way to detect air or combustion gas entry into the cooling system is to visually inspect the system's components.The simplest is to check the coolant level. Significant coolant aeration is unlikely if the system is full and no coolant has recently been added. If it is low, there may have been an overflow discharge, a result of air or gas in the cooling system.A more thorough procedure is to pressurize the system [75 to 103 kPa (11 to 15 psi)] and check for external leaks:* Hoses and lines.* Clamps and connections.* Water pump seal.* Radiator, heat exchanger/expansion tank cap.* Radiator core, header and tanks.* Gaskets and drain plugs.All of these could be sources of leaks and should be repaired immediately.A properly functioning radiator cap is crucial to sealing and maintaining the cooling system pressure. If the cap is not seated tightly in the filler neck or the pressure relief