TUBE AS 1418650 - Caterpillar

Engine: G3520B (S/N: GET1-UP; GLF1-UP)Generator Set: G3516C (S/N: GSB1-UP; GZZ1-UP; TJB1-UP; TJC1-UP) G3516E (S/N: GAS1-UP; SLY1-UP) G3520B (S/N: CWD1-UP; GZP1-UP) G3520C (S/N: MAD1-UP; GZJ1-UP; GZK1-UP; GZL1-UP; GZM1-UP; GZN1-UP; B9P1-UP; HAT1-UP; CWW1-UP; CWY1-UP) G3520E (S/N: GZG1-UP; SXY1-UP)Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use a solution that is identified below.Problem
Failures of the 258-8725 Water Pump Gp (Jacket Water) on the above generator set engines have been reported. The primary failure mode has been coolant leaks through the pump's weep hole due to a damaged water seal.Damage to the water seal occurs when a seal overheats. Dry running of the pump or pump cavitation will cause overheating of the water seal.The characteristics of the design of the pump are being evaluated. The following factors are the main contributors to dry running water pump seals and water pump cavitation:
Application
Installation
Design of the cooling system
Maintenance
OperationSolution
The above problem continues to be investigated. In the interim, Caterpillar recommends the following solution:
The cooling systems must be designed to Caterpillar requirements.
Ensure that the following proper maintenance practices are used: filling procedure for coolant, engine starting procedures, check for external restrictions and purge air from the cooling system.Filling and Venting
While the coolant system is filled, air can be trapped. Proper filling and venting will minimize these air pockets. Refer to the Application and Installation Guide, LEBW4978, "Cooling Systems" for details about filling and venting. Also follow the guidelines for filling and venting the cooling system.
The engine must be filled from the bottom with coolant at a rate no faster than 19 L (5 US gal) per minute. The cap must be removed from the expansion tank during filling of the cooling system.
The vent line must be routed with a continuous upward slope from the highest point of the engine's cooling system to the bottom of the expansion tank.For a system with a volume that is greater than 284 L (75 US gal), the vent lines must be a minimum diameter of 9 mm (3/8 inch).For a system with a volume that is greater than 568 L (150 US gal), the vent lines must be a minimum diameter of 13 mm (1/2 inch).Engine Start-Up
Perform the following procedures in order to ensure that the air is purged after a cooling system has been filled:
Do not accelerate the engine directly to high idle speed.
Run the engine at low idle speed for approximately ten minutes.
During the initial ten minutes of running, monitor the expansion tank and maintain the coolant level above the minimum mark.Design of the Cooling System
The design of the cooling system must be evaluated if the commissioning procedure for the cooling system has not been completed successfully.All systems must be designed as shown in the guidelines in Application and Installation Guide, LEBW4978, "Cooling Systems".Refer to Engine Data Sheet, LEKQ8288, "Sizing Customer Furnished Cooling Systems" for sizing information for the cooling system.For guidelines for the field test of the cooling system, refer to Engine Data Sheet, LEKQ7235, "Cooling System