2004 GMC T8500 Service and Repair Manual

The GMC T8500 sat at the top of GM's T-series tilt-cab range in 2004, the GMC-badged twin of the Chevrolet T8500, and this factory service and repair manual covers it in both of that year's chassis configurations, T8F042 and T8F064. Each is a straight truck with a low tilt cab, and each runs the turbocharged 7.8L inline-six diesel of 475 cubic inches that Isuzu built for GM's medium-duty trucks. Procedures, specifications, torque values, wiring diagrams, diagnostics and maintenance schedules are written for the 2004 build, so the numbers you work to are the ones this truck left the plant with.

Engines covered

• 7.8L inline-six (475 cu in) — turbocharged, diesel

Body styles covered

• straight truck, low tilt

Trims covered

• T8F042
• T8F064

Known issues on the 2004 T8500. No recalls are on federal record for this model year, and NHTSA holds no owner complaints against it either. With a clean record, the value of this manual lies in routine and preventive work: the engine, fuel injection, air brake, driveline and electrical procedures, with the specifications and torque values each step calls for.