COMPRESSOR G 3Y3810 - Caterpillar

EngineC2.2 (S/N: C6M1368-1368,3955-3955,3976-3976,4230-4234,4238-4247,4640-4640,4651-4653,4698-4698,4709-4712,4725-4727,5041-5048,5051-5058,5635-5644,6335-6339,6488-6492,6849-6849,6864-6864)Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
There have been isolated instances of coolant leakage from the bottom of the water pump at low engine hours on certain C2.2 engines. The affected engines have a low mounted fan on 340-5781 Cylinder Block Gp or 420-6407 Cylinder Block Gp.Solution
The water pump contains a rotary seal. Engine coolant is used to lubricate the rotary seal and maintain an adequate sealing film to reduce heat generation. During normal operation, a small amount of coolant and vapor will pass over the seal into a chamber within the pump. The chamber allows the coolant to evaporate through the weep hole and the vent holes in the pump.In some ambient conditions and operating conditions, not all the liquid will evaporate. In this situation, the liquid can be expelled through the weep hole. A loss of less than one drop of coolant every 10 seconds from the weep hole is acceptable.The rotary seal within the pump can trap debris between the seal faces. The seal will usually expel the debris within 30 hours of operation. During this period, there may be a significant loss of coolant through the weep hole.If there is insufficient coolant flow, the rotary seal can be damaged. In this situation, the leak rate from the weep hole will be greater than 1 drop every 10 seconds.Required Information
Take photographs of the engine bay area, the engine cooling fan, and the area where the water pump is leaking. Ensure that the photographs are clear. Also, ensure that the photographs have a file name that contains the CPI issue number, the engine serial number, and the date of repair.
If possible, take clear photographs of the machine and engine data plates. If photographs are not possible, record the machine model, the machine serial number, the engine arrangement, and the engine serial number in a Word document.
Record the following information at time of repair:
Photograph of installed engine cooling fan
Cooling fan part number and model information, if available
Installed air flow direction, that is, Puller-type or Pusher-type
Provide a copy of the full service history of the engine. This copy should include the following items:
Engine oil specification and grade
Oil sample interval
Oil filter replacement history
Fuel filter replacement history
Fan belt tensioning history
Details of any cooling system repairs, including any water pump replacement, that is not recorded on SIMSi.Procedure
The following information applies to 371-0183 Water Pump and 439-4992 Water Pump.
If a coolant leak is suspected near the water pump, determine if the leak is a new event. Remove any coolant stains from the water pump and the front of the engine.
Check the coolant level. Refer to "Operation and Maintenance Manual", Cooling System Coolant Level - Check.
Monitor the area around the water pump regularly for signs of a coolant leak.
Monitor the leak rate from the weep hole in the water pump. If the leak rate is greater than 1 drop in 10 seconds