3 Major Issues of Running Hydraulics Too Hot In addition to contamination, heat is one of the worst troublemakers for hydraulic systems. However, improvements in filter technology is rapidly pushing it into the number one spot. Some machines that are running continuously can put the thermometer to temps as high as 110°C, this can leave create some serious damage that you need to know about. Oil Life Hydraulic oil that gets very hot can suffer from oxidation (air) and hydrolysis (water). This is when there is air and water present in the system. The trouble comes when the temperature rises as according to Arrhenius’s Law there is an increase in temperature of 10°C and reactions happen considerably faster. For example, look what happens if you pour cooking oil into a container such as a glass jar. Over the days you’ll see it slowly change to a darker colour. This is the sign that oxidation has taken place. However, if you add cooking oil to a hot frying pan, it will go black very much faster due to it being in a higher temperature. As engineers, we know that oil that is running at temperatures as high at 110°C is going to get very black and it’s going to smell very bad. This is not something that is beneficial to a hydraulics system. Oil Viscosity The viscosity of hydraulic oil needs to be suitable during operation for both transmission of power and lubrication. This is very difficult to get right when there is a huge gaping hole between the temperatures of oil at a cold start, say 5°C, and that after continual running at 110°C. It’s going to be hard to get hold of oil that can manage to perform in that type of scenario. Seal and Hose Life Although seals and hoses are improving in design and materials all the time, they can still operate at their best with a temperature of 82°C before degradation begins. Even just 10°C above that temperature can have a huge effect on their lifespan. In summary, running a hydraulic system at such a high temperature does nothing for its lifespan or performance. It’s a short cut to degradation and the receipt of several high priced maintenance related invoices.