Drips can be a drag.

Mechanics, if you've heard it once, you've heard it a thousand times: Class III oil drips are bad news and make a vehicle NMC.

That's true most of the time. But there are a couple of circumstances where you need to do a little more detective work before you deadline the vehicle.

Recuperator 

During engine start-up and shutdown, whether the engine is installed or out for ground hop operations, you may observe oil dripping from the drainage and weep holes on the engine's recuperator. You might also notice blue smoke coming from the exhaust.

Either situation may or may not indicate a problem. To find out for sure, follow these steps:

1. Start the engine and run it at idle speed for three minutes.

2. After three minutes, check the recuperator drainage and weep holes for oil leaks. If you see no leakage, you can stop the test and shut down the engine. The tank is FMC.

3. if you see oil leakage after three minutes, continue to run the engine at idle tier another 10. Check for leakage again. If you see any oil leakage after 15 minutes of operation at idle speed, the vehicle is NMC. Report the leak to your support.

Make sure you have the oil and coolant hoses hooked tip to the engine when performing this test during ground hop!

Reduction Gear Box

During low rpm operation, yon may notice a continual drip from the #10 seal area of the reduction gear box (RGB) without blue exhaust smoke or a measurable oil loss.

The viscosity of the RGB's synthetic oil is quite different from petroleum-based oil. So any oil spread you see may make the leak appear worse than it really is.

As long as the oil accumulation does not exceed one ounce per hour, the vehicle is FMC. Report any leak that exceeds one ounce.

You'll find the complete scoop in TACOM maintenance advisory message 05-048. Get a copy from your TACOM LAR or check it out online: https://aeps2.ria.army.mil/commodity/mam/tacom_wn/O5/mam05-048.html

You'll need your AKO or AEPS login and password to access the website.