Hydraulic Oil – Protecting Your Investment

As manufacturers of heavy construction equipment continue to successfully address the industry’s demand for better performance, faster production and higher output levels, the importance of hydraulic oil maintenance is fast becoming the hot topic on everyone’s mind.

“Manufacturers everywhere are gaining an understanding of hydraulic system health in regard to warranties and equipment life,” says Jeff Popa, Service Manager at Schwing America’s headquarters in White Bear, MN. “It’s not just an issue for the concrete pumping industry.”

For the pumping industry specifically, Popa says the pump kits of today are equipped for higher flows, higher pressure and tighter tolerances to accommodate higher output demands and a variety of mix designs. These technologically advanced pump kits require a more rigorous hydraulic oil maintenance schedule to keep up with the performance requirements.

“The engineering advancements now standard on today’s concrete pumps require more attention to everything from the type of oil you purchase to maintenance schedules that assure clean, filtered hydraulic oil is running through the system at all times,” says Popa.

It’s important that every operation research their hydraulic oil options and make an educated purchase. Suppliers offer hydraulic oil for pumps operating in arctic, mild, and tropical conditions, (ISO 32, ISO 46 and ISO 68 respectively). Multi-viscosity oils that stretch the range of safe operating temperatures are also becoming a popular purchase in areas without notably extreme climate variances. “Besides contamination, temperature has the most detrimental effect on hydraulic oil,” says Popa. “The right oil can alleviate some of that worry.”

Popa also says that developing simple, everyday routines, especially in extreme weather conditions, is the first step in hydraulic oil and system maintenance. He uses the unpredictable Minnesota climate as an example: “You’ve just got to start slow,” he says. “Cold Midwest mornings are tough on your car – they’re tough on the pump, too. Operators should be advised to allow everything a little warm up time before you demand too much from it.” By engaging the agitator circuit during set-up, operators can speed the warm-up process on Schwing pumps.

But hydraulic oil maintenance isn’t just that easy. A recently released memo from Schwing America to their customers emphasizes and outlines the importance of strict, preventative maintenance when it comes to clean hydraulic oil. According to the memo, hydraulic experts estimate that 70% of component failure is due to surface degradation caused by excessive dirt and water contamination in hydraulic systems.

“Contaminants are introduced by operation, pure and simple” says Popa. “The cylinder seals, valve seals, bearing seals and reservoir breathing all cause friction and introduce moisture and particles into the oil that simply aren’t conducive to the health of the pump.”

Open circuit systems feature large oil capacity (150-200 gallons) and feature pumps rotating in one direction. The extra oil capacity minimizes friction between parts, and an elementary design and layout makes maintenance less complicated, leaving less room for accidental contamination. Hydraulic oil remains cool and clean, reducing wear on components and aging the oil at a slower rate.

There are other ways to introduce contaminants that pump owners and maintenance crews maybe haven’t considered. Through the disassembly and assembly of components and adding make up oil, the hydraulic systems become susceptible to pollution. The introduction of water to the hydraulic oil is also harmful, and can happen when the water box is not drained after the pump is shut down. The condensation process after dramatic heating and cooling may also cause water contamination.

Popa says preventative maintenance is the key to minimizing the risk of catastrophic failure from hydraulic oil contamination.

“It’s easy to think of the hydraulic oil in a concrete pump the same way you would the oil in your car. Checking and changing the filters, switching out the oil on a regular basis – you don’t risk the health of your engine by ignoring these responsibilities, and you don’t take a chance on your pump kit either.”

Opinions vary when it comes to maintenance schedules for optimum hydraulic system health. Schwing America’s service department recommends an extensive daily maintenance checklist for operators and/or maintenance crews. Draining moisture from the hydraulic tank, draining the water box, checking the oil level, cleaning the hydraulic cooler fins, and conducting an overall check for any significant maintenance needs are all important end-of-the-day procedures.

More extensive preventative maintenance, such as filtering the hydraulic oil, is recommended every 500 hours at the very minimum. The use of filter carts, instruments used to filter new hydraulic fluid or condition fluid already in use, is becoming a popular practice among operations with strict maintenance routines. This process provides piece of mind that there’s no contamination right out of the drum.

Changing the oil filter is also important. Some pumps come equipped with an integrated alarm system that sounds when it’s time for a change. If the pump is not equipped with an alarm, service experts recommend a filter change-out every six months. The system flush – complete oil change-out, tank cleanout and filter cart use – is highly recommended once every year.

In tandem with heavy equipment manufacturers nationwide, Schwing America is working to develop an analysis program in which pump owners are required to bring in their pump during the warranty period for hydraulic system inspection and maintenance. “Hopefully installing a program like this will bring the issue to the forefront,” says Popa. “It’s a well-known fact that a healthy hydraulic system is an important part of a healthy pump. But not everyone understands how integral and vital preventative maintenance could be to the performance and life of the machine.”

Proper record keeping can keep a pump owner on top of regular maintenance. And when combined with timely boom inspections and cosmetic care, these investments will be returned in full at trade-in time or when selling a pump outright – not to mention the peace-of-mind knowing that you are sending your equipment out everyday in top operating condition.