It has been a reasonably warm autumn and winter so far, barring a couple of very cold days here and there. If you regularly monitor the temperature and check this against the peak operating temperature of your chosen hydraulic fluid and oil, you may not have had to make any adjustments so far, but it is inevitable that hydraulic equipment that is used or stored outdoors will require a fluid change at some point during the change of the seasons. Of course, the oil and fluid are not the only parts of hydraulic equipment that need checking and maintaining during colder weather; seals and hoses are also liable to suffer from the effects of the cold, as well as the higher pressure inside from using fluid that may be too viscous at low temperatures. The increased resistance of hydraulic fluid that has become thicker leads to higher pressure inside the cylinders and hoses and if they are not designed to cope with a significant extra force, they can fail and leak. When hydraulic fluid gets too cold it becomes more viscous, thereby decreasing the static pressure of the fluid. In extreme cases the fluid can actually congeal, rendering it useless. Reduced static pressure in the fluid causes air bubbles to form due to the suction on the pump inlet. These air bubbles then get compressed when the machinery is in use and burst, causing loud popping noises and vibrations which can damage the equipment, and depending on the application of that hydraulic machinery, could cause further problems. Excessive wear on parts can lead to mechanical failure, which is costly as repairs need to be made and work is often stopped as a result. Lubricating oil is also subject to the same effects from the cold, and the extra wear caused by oil that has congealed can have a far reaching impact on business productivity, leading to mechanical failure when it is least expected. All machinery has an expected life span and maintenance schedule to keep it in working order and replace parts that get damaged, but if there is a significant amount of extra wear on parts due to inadequate lubrication, this will not have been accounted for in the schedule. These problems are easily avoidable with a regular preventative maintenance schedule and a checklist for all staff tasked with using hydraulic equipment, so they know what to be aware of and what to report. When temperatures get lower there may be no suitable hydraulic fluid for some types of equipment, so heaters (if there are none built in) can be used as a last resort to warm the cylinders and reservoir, getting the fluid inside to the correct temperature for proper functioning. If hydraulic fluids have not been changed to cope with any temperature drop they are exposed to this year, then now is the time to take action. Draining and flushing the system should be done every time the hydraulic fluid is changed, to ensure there are no adverse effects from mixing two different fluids (although some can safely be mixed). One good tip to bear in mind is to take the old fluid away before bringing the new one over, that way there can be no accidental re-filling of the old fluid back into the system. Establishing a plan of preventative maintenance (if this has not already been done) is vital to keep hydraulic machinery functioning for as long as possible, reducing unexpected downtime and the associated costs. Although the extra responsibility and materials may require investment now, the benefits of no unplanned lapses in productivity far outweigh those costs.