Tips for Checking Semi Fluids in the Wintertime

The fluids used in heavy diesel equipment are specifically designed to be able to function well in just about any climate and temperature. However, if those fluids are neglected, the extreme cold of some winters can result in problems for equipment operators, so it’s important not to cut any corners with regard to diesel maintenance.

Keep up to date with inspections and maintenance of all the semi trucks in your fleet during the winter to make sure the fluids are in good condition. Here’s a quick overview of how you should perform your semi truck fluid checks in Ocala, FL.

Lubricating oils

If you’re going to be driving through cold areas this winter, you can expect the chilly temperatures to be rough on your engine, especially when you first start up your vehicle. It’s important, then, to use the right oil when changing it, and regularly check to make sure it’s in good condition. This will ensure you get better long-lasting performance and protection out of the oil.

There has been an increased use of synthetic and semi-synthetic oils, which have a longer lifespan and allow truck owners to get a lower range of viscosity with their engine oils. You can use these synthetic oils all the time, or even switch back and forth between synthetic and mineral-based oils. But the big advantage of low-viscosity oils when the weather is cold is that it will take less energy to start the engine. Due to anti-idle laws that exist for trucks in many areas, it’s very important to be able to cut down the battery drain that would be caused by frequent starts.


You should always maintain a 50/50 mixture of coolant and water—the only exception is if you’re going to be driving in Canada or Alaska, where you may need to use a 70/30 coolant to water mixture. Otherwise, in most other cases, too high of a concentration of coolant can result in the mixture starting to thicken into a sort of paste, which will lead to poor performance, as the water pump will have to work harder. Too little coolant, on the other hand, will leave you vulnerable to corrosion, and you could also have problems with freezing in areas where the temperature is particularly cold.

Diesel exhaust fluid (DEF)

If you have a diesel truck with an engine that was built in 2010 or later, you may have diesel exhaust fluid. This fluid gets implemented into your exhaust stream to alter nitrogen oxide, which is one of the main chemical components of smog. You must have DEF to run this type of engine.

DEF is composed primarily of water, though, so if you have prolonged exposure to temperatures of 12 degrees or lower, it will freeze. The good news is that, if it freezes, it can thaw out and still function properly, but if it freezes and expands, it could result in the container bursting if you don’t leave enough room to account for the freezing.

For more information about semi truck fluid checks in Ocala, FL this winter, contact J & M Trailer Repair today.

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