M11 Industrial Operation and Maintenance – Coolant Loss – External

Symptom Tree  

Coolant level is above specification

Check the coolant level. Refer to the OEM service manual.


External coolant leak

Inspect the engine for coolant leaking from hoses, draincocks, water manifold, jumper tubes, expansion and pipe plugs, fittings, radiator core, air compressor and cylinder head gaskets, lubricating oil cooler, water pump seal, cylinder block, and OEM-mounted components that have coolant flow. Refer to the OEM service manual.


Radiator cap is not correct, is malfunctioning, or has low-pressure rating

Check the radiator pressure cap. Refer to the OEM service manual.


Fill line or vent lines are restricted, obstructed, or not routed correctly

Check the vent lines and the fill line for correct routing and for restriction. Refer to the OEM service manual.


Coolant fill line is restricted or obstructed

Check the coolant fill line for restrictions or obstructions. Refer to Procedure 008-066 (Coolant Level) in Section 3.


Engine is overheating

Refer to the Coolant Temperature Above Normal symptom tree.

Contact a Cummins Authorized Repair Facility

Last Modified:  18-Nov-2004