HMMWV, Hummer H1 & Military Vehicle Repair

A veteran-owned shop for military iron

We are a Christian, veteran-owned shop, and military vehicles are a niche we are glad to see roll in. They are not complicated machines — they are stout, purpose-built, and stubbornly repairable — but they are unfamiliar to most shops, and finding someone willing to touch a surplus truck is half the battle. We know the platforms, the engines, and the failures they are known for.

Who we do this work for

• Cities, counties, and departments — municipalities, fire departments, emergency management, and public works offices that acquired HMMWVs, 5-tons, or brush trucks through surplus programs, then found their usual fleet vendor won't service them and there's no dealer network to fall back on. Departments can run this through a fleet account for scheduled maintenance and priority scheduling when a unit is needed.
• Businesses — ranches, construction outfits, utility contractors, and recovery operations running ex-military trucks as working equipment, where a down vehicle costs real money.
• Private owners and collectors — H1s, restored Humvees, deuce-and-a-halves, and surplus rigs kept road-legal and running right.

HMMWV and Hummer H1

The military HMMWV and the civilian Hummer H1 are the same animal underneath: Detroit diesel power, geared hubs, portal-style ground clearance, and a drivetrain that will outlast the body. HMMWVs run the 6.2L or 6.5L — naturally aspirated or turbo — and the last H1 built, the 2006H1 Alpha, got the 6.6L Duramax and an Allison transmission, which makes it a different truck to service from everything before it. The problems are well-documented on all of them, which makes them straightforward to diagnose once you know where to look.

• 6.2L and 6.5L Detroit diesel — naturally aspirated and the 6.5 turbo in later trucks
• 6.6L Duramax — H1 Alpha — the 2006 final-year H1, with the Allison behind it
• PMD / FSD failure — the heat-related injection pump driver module fault that causes hot stalling; the fix is relocation and proper heat-sinking
• Injection pump and fuel delivery — stale fuel, contamination, lift pump problems, and hard starting
• Glow plug systems — plugs and controllers that turn cold mornings into a fight
• Cooling systems — these run hot by design and are unforgiving of a marginal radiator or fan clutch
• Geared hubs and halfshafts — leaks, wear, and the noises that mean it is time
• Brakes — including inboard brake service on the platform
• Engine swaps — service and diagnosis on trucks already converted to Duramax or other power

Surplus and other military platforms

• M35A2 "deuce and a half" — multifuel inline six, air systems, and brakes
• M939 series 5-tons — Cummins power, air brakes, and driveline work
• LMTV / MTV family — Caterpillar-powered medium tactical vehicles
• Trailers and support equipment — brakes, lights, bearings, and axles

Just bought one at auction? Surplus vehicles come off long storage, and the list is predictable: contaminated fuel, dried seals, aged-out tires, tired batteries, and brakes that have not moved in years. Bring it in and we will work through it and hand you a prioritized list — what it needs to be safe, and what can wait for the budget.

What we do not do

We are an independent repair shop — not a government contractor, and not affiliated with AM General, the military, or any surplus program. We work on the diesel engines, drivetrains, brakes, and chassis systems. We do not do demilitarization work, armor, or anything weapons-related, and we do not handle title or registration questions on surplus vehicles.

Related services

• Diesel engine repair
• Fuel injector & fuel-system repair
• Cooling system repair
• Brakes and suspension
• Unimog service — the other expedition-grade platform we work on

Bring it by

We are at 2900 N FM 973, Austin, TX 78725, serving the Greater Austin Area (Travis, Bastrop, Williamson, Hays). Call 512-717-2777 and tell us what you have and what it is doing — and if you served, thank you. We also run discounts for veterans and active-duty military.

Common questions

Do you work on HMMWVs and Hummer H1s?

Yes. The HMMWV and the civilian H1 share a platform and a drivetrain. HMMWVs run the 6.2L or 6.5L Detroit diesel, naturally aspirated or turbocharged, and the final-year 2006 H1 Alpha came with the 6.6L Duramax and an Allison. Most of what we see on any of them traces to the engine, the geared hubs, the cooling system, and the brakes. We are an independent shop — not affiliated with AM General or the military — which mostly means we will actually take the work.

My 6.5L keeps stalling when it gets hot. What is that?

Almost always the PMD — the injection pump driver module, sometimes called the FSD. It is heat-sensitive, and when it gets hot it cuts out, then restarts once it cools. The standard fix is relocating the module off the pump to a cooler spot with a proper heat sink. It is one of the best-known failures on the platform and we see it constantly.

I just bought a surplus military truck. Can you make it road-ready?

Usually, yes. Surplus vehicles come off long storage, so the common list is fuel-system contamination and stale fuel, brakes, cooling, batteries and charging, tires that are aged out regardless of tread, and leaks everywhere seals have dried. Bring it in and we will go through it and give you a prioritized list — what it needs to be safe, and what can wait.

What other military platforms do you service?

The diesel side of most of them: the M35A2 "deuce and a half" with its multifuel inline six, the M939 series on Cummins power, and the LMTV/MTV family running Caterpillar engines. If it has a diesel engine, brakes, and an axle under it, we can work on it — call and tell us what you have.

Our city department has surplus vehicles nobody will service. Can you help?

Yes — that is a common call. Municipalities, fire departments, and emergency management offices end up with HMMWVs, 5-tons, and brush trucks through surplus programs, then find their usual fleet vendor will not touch them and the dealer network does not exist. We service them like any other diesel, and departments can set up a fleet account for scheduled maintenance and priority scheduling.