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Proper Maintenance Key to Hydraulic Breaker Life, Performance
As tough as hydraulic breakers are, they still demand a crack
maintenance program to keep them hammering away. All
hydraulic breakers, regardless of design or manufacturer,
have the task of shattering, cracking or splitting material. The
assignment isn't exactly gentle on the equipment. Wear and
tear is an outright certainty, so maintaining the breaker is vital
to keeping it running at peak efficiency.
Breakers will eventually fail after years of service, but the life
cycle and performance of a given unit can be greatly enhanced
through proper maintenance, which can be viewed from three
separate perspectives: routine maintenance by the contractor,
periodic rebuilds by the manufacturer, and preventative maintenance features within the breaker itself.
Lubrication is the first line of breaker maintenance. Without lubrication, metal-to-metal contact between the breaker's tool and bushing cause the bushing to wear out quickly, subsequently exposing the breaker's major components to serious damage.
The lubrication process begins by applying down pressure on the tool to ensure that it is pushed all the way into the breaker, eliminating the possibility of grease filling a chamber between the piston and the top of the tool. Lubricant should be applied until it comes out of the lower bushing area, which indicates that the breaker cavity is full and ready to go to work. A paste or grease film should always appear on the tool at the lower bushing while the breaker is operational. The absence of grease is a good visual indication that it's time to apply more lubricant.
Several breaker manufacturers offer their own chisel paste or other lubricant designed specifically for breakers. Standard grease is inferior to specially designed chisel pastes because the heat and pressure from the working tool will cause the grease to melt and run, which increases the frequency of lubrication applications. Although the cost for a tube of chisel paste or special shank grease is higher than the price of regular grease, manual lubrication with paste is only required once every two hours on average, compared with one hour or less intervals using standard grease.
Having the operator stop work to apply grease twice as often can cost a contractor far more in downtime than can be saved using the cheaper lubricant. Additionally, using cheap grease may save nickels and dimes in the short term but could eventually add up to thousands of dollars in tool steel replacement costs.
Even with the very best lubrication techniques, the bushing will wear out and need to be replaced at some point. Measuring the bushing diameter to see how much it has worn often requires that the tool be removed. A simple measurement trick that can be performed without disassembly is to take a 3/16-inch drill bit and try to slide it between the tool and bushing. Typically, at most about 1/4-inch of space is the allowed wear limit, so if the drill bit fits between the tool and the bushing, the tool should be taken out so the bushing can be properly measured to see if it has reached the designated wear specification.
Many hydraulic breakers feature a nitrogen gas assist that should also be maintained in the field as necessary. Expansion and contraction due to heating and cooling will lower the gas pressure in the breaker's piston accumulator, much like car tires will gradually lose air.
Gas pressure checks don't need to be done on a daily basis. And unlike car tires, there's nothing visual to suggest when the pressure should be checked. Instead, simply monitor the breaker's performance. If there is a noticeable drop in the breaker's power output, it could be an indication of low gas pressure. Manufacturers recommend using a special kit and following the operator's manual while performing this check.
Breakers that are lubricated properly but operated incorrectly can suffer the exact same wear and tear on the bushings and tool as if there had been no lubrication at all.
One specific aspect of proper operation involves the hydraulic flow going from a carrier to the breaker. Although machine specifications may indicate a good match, a carrier should be tested at least once a year, and more often in heavy-duty applications, to ensure that it is delivering the correct fluid levels to the breaker. Unfortunately, many contractors fail to have their carriers tested, either due to a lack of awareness or to avoid the expense. It's important to realize that flow problems can pose just as much risk of damage to an excavator or other carrier as they would to the breaker. Improper machine setup is a problem from which no breaker can hide.
Although often classified as an attachment, a hydraulic breaker is a specialized piece of machinery. Like most products, many maintenance and operation issues can be handled correctly in the field. But even with proper care, a hydraulic breaker will require a periodic overhaul to replace all of its wear components.
The terminology for such a job varies. Rebuild, refurbishment and recondition are a few of the phrases out there. There is no set timetable for a breaker rebuild, as it largely depends on the application and size of the breaker. The type of repair that is actually done will differ as well, depending on who is doing the repair and on customer preferences.
Common practice with a recondition is to replace every single wear item on a breaker, as well as to perform a complete and thorough inspection of the unit. Bushings, tools and retainer bars are replaced, while the piston, cylinder and pressure accumulator are inspected. The repair work is usually topped off with a paint job.
Occasionally a breaker that hasn't been heavily used will be brought in for a recondition. Such a machine may not have experienced much wear and tear, so the customer may be given the option of replacing some parts while trying to get more life out of others.
A more frequent occurrence is for a breaker to have certain wear items that only have a few months of use left in them. The customer still has the option of leaving these parts in, but doing so would mean a return trip to replace the parts just weeks or months later. In addition to being more convenient, another upside of immediately replacing all the items is that the manufacturer may offer a renewed warranty since the breaker has essentially been refurbished up to near-new condition. The same guarantees may not apply if some parts are not replaced and something goes wrong before the next repair.
It's generally recommended to take a breaker to the manufacturer, distributor or another qualified professional for a rebuild or recondition. However, many hydraulic breakers, especially the smaller varieties, are designed so that they can be more easily maintained by end users with the appropriate training and experience.
"Automatic" is a big-time buzzword for today's equipment. Anything the equipment can do by itself to take another task out of the operator's hands should minimize downtime and increase overall productivity. Incorporating a number of automatic technological features, hydraulic breakers are no different.
Not surprisingly, nearly every breaker manufacturer has some technique for automatic lubrication.
Different methods are employed on various breaker sizes and brands. A number of systems utilize a hose that runs from the carrier to apply consistent lubrication to the breaker. Some manufacturers produce breakers that come standard with a lubrication cartridge mounted directly onto the breaker itself. With this system, literally all that is required of the operator is to change the tube when it's empty. Even with the "automatic" lubrication system the operator still needs to periodically check for grease film on the tool to ensure the system is operational and properly adjusted.
More lubrication than normal is needed for particularly dusty applications. Some breakers feature an optional system to protect the breaker from dust penetration by providing an additional seal that prevents debris from entering the unit. This system also keeps chisel paste where it belongs to allow the breaker to run longer without risking wear and tear from a lack of chisel paste.
Another feature that assists in preventing potentially serious harm to a breaker is a power management system. Found on some larger breakers, this system is a tremendous preventative maintenance asset in jobs where lighter material is being broken. Rather than unleashing a full-power blow, a breaker equipped with power management can limit itself to 50-percent power until it hits against hard material that dictates a need for full impact energy. If full power is used in light material, the breaker's working tool will literally fire out through the material, and only a metal-to-metal stop against the breaker's retainer bars will keep the breaker intact, causing unnecessary strain on the machine.
Conversely, in applications where extremely hard material must be broken, damaging shock waves can be reflected from the material into the breaker's tool and piston. One unique system allows this rebounded energy to be collected in a high-pressure accumulator, which effectively protects the internal components from the shock waves. As an added bonus, the breaker can then deliver the accumulated energy in the next blow.
Breakers are charged with the unforgiving task of pounding apart hard material without falling apart themselves. Some contractors take the approach of using a breaker when they need it and throwing it to the side when they don't because "it's just a hammer." In actuality, hydraulic breakers are specialized machines that require maintenance just like any backhoe, carrier or other piece of machinery on the job site. Through new design and technology, manufacturers have simplified breaker maintenance to make it a user-friendly task. Give a breaker the time and attention it deserves, and it will return the favor with productive and impressive results.