B5.9G, B5.9LPG, B Gas Plus, B LPG Plus – Coolant Loss

Symptom Tree  

Radiator or cab heater is leaking coolant

Inspect the radiator, cab heater, hoses, and connections. Refer to the OEM service manual.


Transmission oil cooler or torque converter cooler is leaking

Check the transmission oil cooler and torque converter cooler for coolant leaks. Refer to manufacturer’s instructions.


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 a Cummins Authorized Repair Facility.


Engine is overheating

Refer to the Coolant Temperature Above Normal symptom trees.

Contact a Cummins Authorized Repair Facility

Last Modified:  15-Feb-2005