It might seem silly to rely on your sense of smell as a tool for diagnosing problems with the oil in your hydraulic equipment. However, this approach is more scientific than you think. After all, when you smell an odor, you are actually detecting different kinds of molecules that a given substance is emitting. This is exactly what a gas chromatograph does. If you sent your fluid to a lab for analysis, they would almost certainly make use of this tool. So why pay for a lab tech to use a high-tech artificial nose to find out what your own nose could tell you faster, cheaper, and more easily?
Here are some of the common odors and what they mean.
Sour Rotten Eggs: You may detect this pungent odor if your oil is being degraded by oxidation. The odor is released as a byproduct when the oil combines with oxygen, becoming more acidic and subjecting your parts to increase risk of corrosion.
Burnt Food: It should probably come as no surprise that burnt oil has a burnt smell. If your oil is overheating in the system, you may notice this odor. This can occur due to the entire system exceeding the oil’s temperature rating or due to oil contact with compressed entrained air bubbles in hydraulic pumps and other pressurized parts.
Road Kill: A smell of corruption or putrefaction similar to a whiff of road kill can be caused by bacteria dining on the oil in your system. This process will result in corrosive byproducts that can potentially ruin your hydraulic components.
Skunk: If your system is emitting a skunky or sulfur-like odor, you may have compounds mixing together in your oil to create sulphuric acid. This acid should be neutralized by additives in the oil, but you may end up with metallic sulfates in the oil and the oil life will be reduced as the additives get used up.
Almonds: When you detect an almond-like scent, the culprit is a nitrogen compound. It means you have oxidation involving nitrogen compounds going on in your system. You may suffer from oil thickening as well as increased varnish buildup in the system.
Chemical Odors: If you can smell something like gasoline, kerosene, a solvent, or a refrigerant, this is a sign that your oil has become contaminated with that chemical.
At Bernell Hydraulics, we can not only perform a fluid flush to clean out all that dirty, stinky oil, but also help you determine the cause of the contamination and recommend a solution that will help prevent the same problem from recurring.