This factory service and repair manual for the 1999 GMC B7 works with a two-engine list: the turbocharged 7.2L OHV inline-six diesel and the naturally aspirated 7.4L OHV gasoline V8, both in the cab forward school bus designated B7T042. A diesel six and a gasoline V8 call for different diagnostic approaches, and they get separate specifications, torque values and fault-finding procedures here, ahead of the chassis and body sections that serve either build.
Engines covered
- 7.2L inline-six (441 cu in) — OHV, turbocharged, diesel
- 7.4L V8 (454 cu in) — OHV, naturally aspirated, gasoline
Body styles covered
- Bus (school), cab forward
Trims covered
- B7T042
Known issues on the 1999 B7. One owner complaint is logged with NHTSA for this model year, and it concerns the engine and engine cooling. That is the part of the bus this manual documents in most detail on both power units. Cooling system material covers the radiator, pump, thermostat, hoses and fan drive with the procedures, pressure specifications and torque values needed to service them, and the engine sections carry diagnostic routines for the turbocharged 7.2L inline-six diesel and the 7.4L gasoline V8, along with the wiring diagrams for their sensors and controls.
VEHICLE DESCRIPTION: MEDIUM DUTY CONVENTIONAL CAB TRUCKS AND SCHOOL BUS CHASSIS EQUIPPED WITH AN AUTOMATIC TRANSMISSION, HAVE TRANSMISSION SHIFT CABLE END RODS THAT HAVE NOT BEEN CRIMPED TO THE PROP
WITH THIS CONDITION, THE VEHICLE MAY MOVE IN A DIRECTION NOT ANTICIPATED BY THE DRIVER, INCREASING T
DEALERS WILL INSTALL A NEW SHIFT CABLE.
This warranty administration bulletin provides information regarding the field action courtesy transportation policy.
Engine Backfire and Related Driveability Issues
Underbody Component Corrosion The following information may be helpful when addressing underbody component corrosion with customers. Some customers may comment that one or more of their vehicle's underbody components are showing some form o
Underbody Component Corrosion The following information may be helpful when addressing underbody component corrosion with customers. Some customers may comment that one or more of their vehicle's underbody components are showing some form o
Refinishing Aluminum Wheels This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening o re-machining. Only cosmetic refinishing of the wheel's
Refinishing Aluminum Wheels This bulletin updates General Motor's position on refinishing aluminum wheels. GM does not endorse any repairs that involve welding, bending, straightening o re-machining. Only cosmetic refinishing of the wheel's
THIS TECHNICAL BULLETIN PROVIDES A PROCEDURE TO REPROGRAM THE MEDIA DISC PLAYER WITH THE LATEST CALIBRATIONS TO CORRECT A CONDITION OF THE REAR ENTERTAINMENT SYSTEM NOT OPERATING AS INTENDED IN COLDER AMBIENT TEMPERATURE AREAS DUE TO CALIBR
Expanded Availability for Remanufacture and Return (R&R) Electronic Control Modules
Showing the 8 most recent of 24 technical service bulletins on file with NHTSA.
