Takeuchi TB216 Losing Coolant, No Visible Leaks
Fault Codes & Symptoms
Engine coolant level drops during operation. Related symptoms: - Engine misfire on startup - Occasional white smoke from exhaust - Unexplained loss of engine power Operator reports having to add coolant every day. No drips or puddles are seen under the machine overnight.
Confirmed cause: Cracked cylinder head. A small crack was found near an exhaust valve seat in the suspect cylinder upon disassembly. Repair performed: Replaced the cylinder head and head gasket. The cooling system was flushed to remove any contaminants and refilled with the correct coolant mixture. Verification: The cooling system was pressure tested after the repair and held pressure successfully. The engine was run for several hours under load, and the coolant level in the reservoir remained stable. Technician notes: - This type of failure can be intermittent and difficult to find. The coolant was leaking into the cylinder and being burned off as steam, which is why no external drips were visible. - A combustion gas "block tester" using chemical analysis is another good method for detecting cylinder-to-coolant leaks. - Always use a torque wrench and follow the correct bolt-tightening sequence when installing a cylinder head.