HMMWV Oil Change : How To / What You Need To Know

Introduction

This tutorial provides a step-by-step guide to changing the oil in a Military Humvee equipped with a 6.5L Diesel engine. Using the right oil and filter, along with proper techniques, will ensure your vehicle runs smoothly. We'll cover the necessary tools, oil specifications, and detailed instructions for a successful oil change.

Step 1: Gather Required Materials

Before starting, make sure you have the following items:

• Oil: Shell Rotella T6 15W-30 full synthetic oil (for newer Humvees) or Rotella T3 15W-40 conventional oil (for older models).
• Oil Filter: K&N HP3002 (or any high-quality filter).
• Oil Drain Plug Wrench: 9/16 inch.
• Torque Wrench: For tightening the drain plug (20-27 ft/lbs).
• Oil Catch Pan: To collect used oil.
• Rags: For cleaning up spills.
• Tarp: To protect your driveway from oil splashes.

Step 2: Prepare the Engine

1. Warm Up the Engine: Allow the engine to run for a few minutes to thin the oil, promoting better drainage.
2. Position the Oil Catch Pan: Place the pan under the oil drain plug, which is located on the driver's side of the oil pan.

Step 3: Drain the Old Oil

1. Remove the Drain Plug: Using the 9/16 inch wrench, loosen the drain plug carefully. Be cautious as the oil may be hot.
2. Let the Oil Drain: Allow the old oil to fully drain into the catch pan. This may take a few minutes.

Step 4: Replace the Oil Filter

1. Remove the Old Filter: Use an oil filter removal tool to loosen and remove the oil filter. Expect some oil to spill.
2. Prepare the New Filter: Lubricate the rubber O-ring on the new filter with a bit of fresh oil to ensure a good seal.
3. Install the New Filter: Screw the new filter onto the mounting plate by hand until it is snug. Avoid overtightening.

Step 5: Inspect and Reinstall the Drain Plug

1. Inspect the Drain Plug: Check the magnet on the drain plug for metallic particles, which can indicate engine wear.
2. Change the Crush Washer: If necessary, replace the crush washer to ensure a proper seal.
3. Reinstall the Drain Plug: Tighten the drain plug to the specified torque of 20-27 ft/lbs. If using a torque wrench isn’t feasible, tighten by hand snugly.

Step 6: Add New Oil

1. Pour in New Oil: Fill the engine with 8 quarts (7.6 liters) of new oil. Tip the container on its side to prevent glugging and spills.
2. Check the Dipstick: After filling, check the oil level with the dipstick to ensure it's within the acceptable range.

Step 7: Prime the Oil System

1. Disconnect Injection Pump Wires: Disconnect the power wires to the injection pump.
2. Crank the Engine: Turn the engine over for a few seconds to circulate oil without starting it. This will fill the oil filter and build oil pressure.
3. Reconnect the Wires: Plug the injection pump wires back in.

Step 8: Start the Engine and Check for Leaks

1. Start the Engine: Run the engine for a few minutes.
2. Check Oil Pressure: Observe the oil pressure gauge to ensure normal operation.
3. Look for Leaks: Inspect under the vehicle for any signs of oil leaks.

Step 9: Final Checks

1. Recheck the Oil Level: After the engine has run, turn it off and wait a couple of minutes, then check the dipstick again.
2. Clean Up: Wipe down any areas that may have oil drips to identify future leaks easily.

Conclusion

Following these steps will help you effectively change the oil in your Military Humvee, ensuring it runs efficiently. Regular oil changes are essential for maintaining engine health. For your next maintenance task, consider performing a power steering flush or checking the geared hubs. Always refer to your vehicle's manual for specific guidelines and recommendations.