Here's a random google result for "semi def". If it's anywhere near accurate I wouldn't want to deal with it either. The phrase "Do not taunt Happy Fun Ball" comes to mind.
HOW DO I KNOW IF DEF IS BAD?
When DEF becomes contaminated, your truck’s performance will suffer. How can you tell when DEF needs to be replaced? Here are a few red flags:
- Selective catalytic reduction (SCR) system malfunctions
- Illuminated dashboard warning light
- Increased diesel fuel consumption
- Decreased effectiveness of DEF
- Damage to DEF dosing pump, diesel particulate filter, and other components
- Potential engine de-rating or shutdown
PERFORM ROUTINE DEF REPLACEMENTS
Replacing DEF is one of the easiest ways to prevent increased consumption and possible damage to a truck’s engine and systems.
DEF has a shelf life of 12 months in perfect conditions. Whether you’re managing one truck or a whole fleet of trucks, routinely draining the tank/s and refilling with fresh fluid helps prevent problems down the road, especially if you’re planning to sell and want to keep a new buyer happy.
MONITOR THE UREA CONCENTRATION OF DEF
Keeping diesel exhaust fluid pure is essential to its quality. Even contaminants around the fill cap can be a problem. Before undoing the cap to add more fluid, be sure to wipe the cap and the area around it. This reduces the likelihood of dirt and other debris falling into the tank and compromising the fluid.
How do you monitor the quality of DEF? You can use a digital refractometer to check the urea concentration. Ideally, the
concentration should be between 32.5 and 37 percent urea. You’ll likely notice the above listed red flags in accompaniment with drops in concentration. Although one can be somewhat pricey, a digital refractometer can help you get the most from your truck’s DEF despite the short shelf life.
HANDLE & STORE DEF CORRECTLY
Mishandling DEF can render it useless. Certain metals, such as copper, carbon steel, and aluminum corrode when they come into contact with DEF. For this reason, it’s important to use manufacturer-recommended stainless steel or plastic totes for storage. Additionally, be sure to do the following:
- Keep DEF out of direct sunlight.
- Store at a temperature of about 86 degrees Fahrenheit.
- To prevent waste and contamination, consider storing DEF in 2.5-gallon containers vs. bulk containers.
- If you need bulk storage, create a closed loop system — or a fully sealed system that makes it easy to refill DEF storage containers without exposing the fluid to contaminants in the immediate area.
- Never use tap water to clean the components used to dispense DEF. Instead, use distilled or deionized water and follow up with a DEF rinse.
- Never use the same equipment for dispensing DEF to dispense another type of fluid. Use the same equipment each time and for nothing but DEF.