Hummer Automotive Repair Manuals

Interesting Facts About Hummer You Probably Don’t Know – Common Problems – and PDF Manuals for Download…

The AM General Corporation, a subsidiary of the American Motors Company, designed the very first Hummer vehicles.

When the US Army sought contractors for a new multipurpose and high mobility vehicle that could follow the tracks of a full sized HMMWV, AM General was one of the contractors to design a model and the first to finish a prototype vehicle and deliver for testing.

They were awarded the contract after testing in 1985.

AM General planned a civilian version of the car since the 1980s and this was passed because Arnold Schwarzenegger was persistent about it. Sales of a civilian version of the Humvee started under the Hummer brand name by the year 1992.

At the end of 1999, AM General sold the Hummer brand name to General Motors but maintained production of the vehicle. General Motors renamed the first version H1 as they introduced versions H2 and H3.

Until its discontinuation in 2006, H1 was built by AM General and the building of H2 and H3 versions were also contracted to AM General.

From 2006 exportation of the Hummer began. H2 was assembled in Russia and H3 in South Africa for international market distribution.

As oil prices climbed higher and the demand for larger SUV’s declined, General Motors announced in 2008 that the brand will be sold, discontinued or redesigned. In 2009 it was announced many buyers were interested in the Hummer brand.

The same year, it was rumored that the Chinese company, Sichuan Tengzhong was interested in closing a deal with GM for the Hummer and by 2010 the deal went into discussion.

After trying to close a deal in January of 2010, the sale collapsed in February of the same year due to many factors.

GM considered selling parts of assets and although the American Raser Technologies showed interest in April of 2010, that deal also collapsed without success. After that GM officially announced it was shutting down the Hummer brand and offered rebates for sale of over 2000 remaining Hummer vehicles.

The Hummer 1 was the first based on the design of the Humvee. Hummer 2 was second in the range having H2 SUV and H2 SUT variations.

The smallest of the models was H3 and H3T which were based on the GMT355 platform. Even smaller than the others was the 2 doors, open air Hummer HX developed in 2008. A high demand for Hummer H2 limousine was high in Us and then UK and one was created.

Hummer had a lot of criticisms. Hummers without the diesel option have very poor fuel economy and this is even worse when compared to other similar heavy passenger vehicles.

The size was also a problem because the H1 and H2 are noticeably bigger than other SUVs, so parking them or fitting in a garage or driving was a problem.

A study showed that H2 and H3 drivers received more parking tickets than other vehicle owners. Safety is also a problem as a lot of blind spots make parking difficult.

There are also many other safety hazards, including no side air bags or child safety locks.

Common Hummer problems

Like all vehicles, the Hummer has its own typical problems. A lot of complaints seem to come from owners of the Hummer H3 and H3T.

However, having a manual for your car can help point out possible the flaws beforehand and help you identify the source of the problem to deal with it appropriately.

Here are some common problems experienced with some Hummer models.

  • Transmission fluid mixing with coolant: there have been complaints about the Hummer H3T having radiator problems. The oil cooler is manufactured by a Chinese company and can easily rupture even if little or no stress is placed on the vehicle.
    This might be occurring because the cooler has a poor crimp on the seals and this can be tested with low air pressure in solvent. The only solution could be to bypass the transmission oil cooler using the repair manual.
  • Engine start prevented by passlock light: there have been many complaints about the passlock of the Hummer H3 that prevents the car from starting. Drivers have to wait up to thirty minutes sometimes before the engine starts.
    The flashlight from the passlock just keeps flashing as the engine is prevented from starting. The ignition switch is very weak and the anti-theft passlock system ends up becoming a safety hazard instead of a protection.
    A solution is to replace the ignition switch from GM and have a stronger one installed.
  • Engine runs roughly: the engine light of the Hummer H3 has a habit of coming and staying on frequently. There seems to be no real fault with this initially but then a clattering noise comes from the engine.
    Sometimes, the engine can spit out white smoke on start up and the clattering noise is loudest on start up but can become quieter later.
    GM made changes to the 5 cylinder in 20017 and new head valves can be a solution to the rough running engine and constantly blinking engine lights.
  • Body paint problems: the paint at the rear bumper peels off quite easily on the Hummer H2. The paint peels off in sheets and the entire rear quarter is left looking so shabby. The warranty covers this problem; so if you are experiencing it after a few years, you have nothing to worry about. But this problem does not go away after repainting. An extended warranty might cover the second incident but the vehicle owner has the responsibility of repainting the car after this.
  • Leaking valves: the Hummer H3 has a common problem of leaking cylinder valves. The valves seem to go and after every few thousand miles.
    The warranty and extended warranty can cover replacement the first two times but the bill is on the car owner after that. Replacing the valves or the cylinder head with the repair manual seems to be the right solution for this problem.


Purpose of this is to catalog and include one of most comprehensive, useful and accessible “automotive repair PDF manual” database on the web for all Hummer models.

It’s your go-to source for learning all about Hummer – when you can’t find it elsewhere.

To get started, select the intended car model below…

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