Hydraulic oil is the lifeblood of every hydraulic system, from massive machines used in mining and construction to small tractors and diggers on the farm. However, as reliable as modern hydraulics have become, every system still has a weakness: the extremes of hydraulic oil operating temperatures.
This weakness exists at both ends of the scale: extreme heat and extreme cold. Both affect performance and operating efficiency and have the potential to cause damage through overloading the system to compensate for non-optimal pressures. Let’s look at both extremes and how they can affect your machinery.
When we think about temperature as a potential issue for hydraulic systems, we generally assume that heat is the main culprit. But extreme cold can also be as problematic for hydraulic systems. The cold affects machinery operating in freezing conditions, at high altitudes and in regions where the atmospheric pressure is lower than in the surrounding areas. Cold temperatures are particularly problematic for smaller, mobile machines operating during winter.
Extreme cold affects hydraulic systems in many ways, especially the elastomeric components in the system, such as the ones made from rubber. These components can lose their elasticity and become brittle in the extreme cold. When you consider that elastomeric components are used in many crucial parts of the system, from seals to mounts and hoses, any cracks or tears will compromise performance. When working in extreme cold, as a precaution, you should always check these components for cold damage before powering up your machinery.
Every hydraulic machine needs oil to pass through the system at the specified levels of viscosity. Extreme cold increases the viscosity of oil, making it thicker. If the oil is too thick, it won’t behave as intended. For example, it’s important on startup to distribute oil all the way through the system for lubrication and smooth performance. If it’s too thick and doesn’t flow through the system as required, you have the potential for damage. If the oil is so cold it congeals and doesn’t flow at all, these problems become serious.
Tips:
At the opposite end of the temperature scale, extreme heat also affects the viscosity of hydraulic oil. As well as becoming too thin to perform as required, extreme heat also causes the oil to deteriorate faster than normal. As oil deteriorates, it oxidises, which can create deposits of sludge in hydraulic systems. All these problems compromise performance
As the oil thins with heat, it doesn’t lubricate components properly. This causes increases in friction, which in turn can lead to abrasive damage, accelerating the useful lifespan of parts. It also has a negative impact on operating pressure and stresses machinery, leading to damage. With more friction and less lubrication, the machine itself will generate its own heat. If pushed too hard, this will compromise motors, pumps and other components. Over time, if not remedied, extreme heat will destroy the system.
Tips:
Extreme heat and cold will affect the performance of your hydraulic machinery and cause damage if you don’t remedy the issues they cause. If your oil temperature reaches either side of its optimal working conditions, it won’t lubricate the system as intended, becoming too thick in the cold or too thin in the heat. If you’re experiencing performance issues, it pays to identify the problem and address it quickly before it causes downtime.
