W 3500 L4-3.9L DSL (1998)
Heating and Air Conditioning: Technical Service Bulletins
Vehicle - Engine Crankcase and Subsystems Flushing Info.
Bulletin No.: 04-06-01-029E
Date: April 29, 2010
Subject: Unnecessary Flushing Services, Additive Recommendations and Proper Utilization of GM Simplified Maintenance Schedule to Enhance
Customer Service Experience
2011 and Prior GM Passenger Cars and Trucks (including Saturn)
2010 and Prior HUMMER H2, H3
2005-2009 Saab 9-7X
This bulletin is being revised to update the model years and add information about the proper transmission flush procedure. Please discard Corporate
Bulletin Number 04-06-01-029D (Section 06 - Engine/Propulsion System).
An Overview of Proper Vehicle Service
General Motors is aware that some companies are marketing tools and equipment to support a subsystem flushing procedures. These dedicated machines
are in addition to many engine oil, cooling system, fuel system, A/C, transmission flush and steering system additives available to the consumer. GM
Vehicles under normal usage do not require any additional procedures or additives beyond what is advised under the former Vehicle Maintenance
Schedules or the current Simplified Maintenance Schedules. Do not confuse machines available from Kent-Moore/SPX that are designed to aid and
accelerate the process of fluid changing with these flushing machines.
Engine Crankcase Flushing
General Motors Corporation does not endorse or recommend engine crankcase flushing for any of its gasoline engines. Analysis of some of the
aftermarket materials used for crankcase flushing indicate incompatibility with GM engine components and the potential for damage to some engine
seals and bearings. Damage to engine components resulting from crankcase flushing IS NOT COVERED under the terms of the New Vehicle Warranty.
GM Authorized Service Information: Detailed, Descriptive, and Complete
If a specific model vehicle or powertrain need is identified, GM will issue an Authorized Service Document containing a procedure and, if required,
provide, make available, or require the specific use of a machine, tool or chemical to accomplish proper vehicle servicing. An example of this is fuel
injector cleaning. Due to variation in fuel quality in different areas of the country, GM has recognized the need for fuel injector cleaning methods on
some engines, though under normal circumstances, this service is not part of the maintenance requirements.
GM has published several gasoline fuel injector cleaning bulletins that fully outline the methods to be used in conjunction with GM Part Numbered
solutions to accomplish proper and safe cleaning of the fuel injectors with preventative maintenance suggestions to maintain optimum performance. You
may refer to Corporate Bulletin Numbers 03-06-04-030 and 04-06-04-051 for additional information on this subject.
Flushing of A/C lines, radiators, transmission coolers, and power steering systems are recognized practices to be performed after catastrophic failures or
extreme corrosion when encountered in radiators. For acceptable A/C flushing concerns, refer to Corporate Bulletin Number 01-01-38-006. This practice
is NOT required or recommended for normal service operations.
The use of external transmission fluid exchange or flush machines is NOT recommended for the automatic or manual transmission. Use of external
machines to replace the fluid may affect the operation or durability of the transmission. Transmission fluid should only be replaced by draining and
refilling following directions in SI. Refer to Automatic/Manual Transmission Fluid and Filter Replacement.
Approved Transmission Flushing Tool (Transmission Cooler Only)
The Automatic Transmission Oil Cooler Flush and Flow Test Tool is recommended for GM vehicles. Refer to Transmission Fluid Cooler Flushing and
Flow Test in SI using the J 45096.
Service Is Important to You and Your Customer
General Motors takes great pride in offering our dealerships and customers high quality vehicles that require extremely low maintenance over the life of
the vehicle. This low cost of ownership builds repeat sales and offers our customers measurable economy of operation against competing vehicles.