Citgo talks hydraulic fluid options, maintanence

Maintaining a high-clearance sprayer. (Photo: Citgo)

Fluid power is widely used in the latest agricultural and forestry equipment and they are typically exposed to harsh environments. Equipment such as forwarders and tractors may be exposed to extreme temperatures, moisture, dust, and debris. It is important that the equipment perform adequately in any condition.

There are different types of hydraulic fluids that are used in the hydraulic systems of mobile equipment. Water-emulsifying hydraulic fluids, for example, are typically used as a multipurpose fluid. They can power the hydraulics as well as lubricate transmission components, final drives, steering and brakes. Common original equipment manufacturer (OEM) specifications for these fluids are Allison C-4, Caterpillar TO-4 and John Deere J20C.

“The benefit of a water-emulsifying fluid is that it can suspend a small amount of water without causing damage to the equipment,” said Matt Gerber, senior product specialist, Lubricants, for Citgo Petroleum Corp. “In stationary hydraulic equipment, the water will separate from the fluid and end up at the bottom of the reservoir, where it can be drained off. With mobile hydraulics, depending on the environment, this water can either freeze or promote bacterial growth, which is why the emulsifying fluid has an advantage. These fluids also generally have a high viscosity index and are suitable over a wide temperature range.”

(Photo: Citgo)

Many OEMs recommend the same fluid type found in stationary fluid power applications because it can separate fluid from water. These oils can be broken into two categories: zinc-containing and zinc-free.

“Zinc-containing oils are the most familiar and most frequently used in stationary industrial equipment,” said Gerber. “However, these can be used as a hydraulic fluid option in mobile equipment, especially with a common supply reservoir. Non-zinc hydraulic oils are recommended as replacements for zinc-containing oils in environmentally sensitive applications. Often, these fluids are recommended near waterways, in forests or on farms. Zinc can contaminate water and soil, harming aquatic organisms and plants. Non-zinc hydraulic fluids use other chemical compounds, such as phosphorus or organics to achieve the same protection. Many manufacturers also offer biodegradable zinc-free fluids, which is another added benefit.”

(Photo: Citgo)

It’s no secret that mobile equipment should be regularly maintained in order to ensure the hydrualic system performs as design.

“If maintenance is neglected, this could lead to reduced efficiency, equipment failure or potential environmental impacts,” said Gerber.

As a reminder to end-users and equipment engineers, he offered these suggestions for maintaining the hydraulic systems of off-highway equipment:

• Filters should be changed regularly. In outdoor environments, filters trap contaminants and debris that can damage pumps, valves and actuators. Clogged filters reduce flow and pressure of the hydraulic fluid, which causes strain to the system, increases wear on the components, and increases the likelihood of system leaks.
• Hydraulic fluids should be chosen based on OEM recommendations as well as environmental conditions. In applications and environments where a wide temperature range is necessary, a product with a higher viscosity index and good low- and high-temperature properties should be chosen.
• Hydraulic oil degrades due to heat, oxidation, and contamination. A fluid monitoring program can help to create a trend of equipment data, detect issues early, and advise when the fluid has reached its end-of-life.
• Seals and hoses should be regularly inspected for wear, cracks, and leaks. A leak in the system will not only lose oil, but air and contaminants can enter the system at those points.
• All technicians and equipment operators should be properly trained in system maintenance. Documentation should be kept that log items such as equipment service and fluid changes.

Citgo sells its lubricants under the Mystik Lubricants brand. Gerber said that choosing the correct fluid, such as Mystik JT-9 LeakShield AW hydraulic oil or Mystik JT-5 tractor trans-hydraulic fluid as an emulsifying hydraulic, is critical for the harsh environments of mobile hydraulics. Non-zinc fluids should also be considered where possible to help minimize the environmental impact of oil leaks.

“The right fluid will help to extend the life of the equipment and achieve optimal performance,” said Gerber.