Repair — Simply said, a repair procedure is limited to making an old, failed component close to its original shape and size. All failed old components theoretically can be repaired but should not be because certain old failed components are beyond repairing and may not provide the full and desired function like the original. This is where the repairing procedure for every single component is so very crucial for the whole unit to function within its original specification.

In the hydraulic industry, a variety of products such as pumps, motors, valves, controls, and their parts thereof, could be repaired as long as the component dimensions, tolerances, and clearances are within the prescribed limit.

Rebuild — The term “re” comes out of doing it again. What this means is that a used, failed product first is dismantled, then the reasons for the failure and as well the failed components and parts are identified. The relevant unit is then built and assembled again with either new or “remanufactured” components and parts. The term “rebuilding” is very loosely used for a variety of activity.

Rebuilding of a hydraulic pump or motor can also be done with all relevant new components or parts. Therefore, just because the unit was rebuilt does not necessarily means that it is a “repaired” unit. Eventually, a rebuilt unit must go through the dynamic testing process. This ensures that the rebuilt unit has the same engineering specifications — in terms of flow, pressure, and leakage — as a new one.

Remanufacturing — The remanufacturing process has created all kinds of debate and confusion in the hydraulics service market. Remanufacturing functions can be divided into two areas — manufacturing on the existing core and “improved engineered.”

When manufacturing is done on the existing core, the original components or parts are reworked by lapping, grinding, turning, and other engineering processes, to get it back to its near acceptable originality. Such reworked components and parts are determined to function without any ultimate drawback in the whole unit. Such components are built on an original core.

While working on the old core, it is necessary to ensure that the original dimensions are not distorted nor the material composition sacrificed. In many instances, after the surface finish and machining operations, heat and surface treatment is necessary, and then the component is completely finished. Such remanufactured components should possess the same mechanical quality as the original. Based on the component’s function in the whole unit, the extent of remanufacturing is decided. All old used components are not necessarily always accepted for remanufacturing.

Reengineered components are often “improved engineered” and are brand new. The re-engineering term is often called reversed engineering. Technically, qualified service houses often improve engineer the components and parts, to be used for rebuilding a complete pump/motor/valve unit. The reengineering process calls for creating a new drawing for the components, maintaining all the identical dimensions of the original one.

In many cases, the tolerances and clearances in the mating areas are tightened based on application and metallurgy, to improve efficiency and performance. For example, improving the fit between a vane pump ring, rotor, and vanes can improve volumetric efficiency. Tighter control of the fit between the vanes and their respective slots in the rotor can improve performance. In piston pumps and motors, improving the fit between the pistons and their respective bores in the cylinder block can improve both mechanical and volumetric efficiencies.

Valve tolerance and clearances can also be improved with reverse engineering. The tolerances and clearances between a spool OD and its respective bore in the valve body are applied with thorough technical knowledge of the product function, so that the finished product functions with the same efficiency as the original one.

Sometimes, such reversed engineered components or whole products are commonly called as “aftermarket” products. In reality the word “aftermarket” has nothing to do with such manufactured products.

Defining aftermarket

The word “aftermarket” comes out of the market potential for a given line of products, after the original was sold or marketed the first time.

Aftermarket is simply a market opportunity. It cannot be loosely used for a product, as often done. For example, say 10 injection molding machines were sold in the year of 2006. We shall say these 10 machines have 20 hydraulic pumps. The natural lives of these 20 pumps may be two years. Therefore, in 2008 these 10 machines could have generated a market potential for 20 pumps, to be repaired-rebuilt or replaced. This market potential is known as the “aftermarket.”

“Look alike” and “will-fit” terms are also often loosely used. The fact is, many original manufacturers’ product lines that have been declared obsolete by the manufacturer, but others reproduce them in support of market requirements. Most often these products’ patents have run out. Such products, manufactured by others, are often termed as “will-fit” or “look alike.” In reality, most often these products are built to original specifications and function like the original manufacturer’s.

Such products are like generic medicines. The ingredients in the product are just the same as the original. These products will have the branded names and most often are less expensive and available more quickly than the originals. Therefore, such branded hydraulic products could be cost effective as well as, as they maintain the productivity of the given machine and equipment, because the machine and the equipment do not have to be under breakdown for want of the product.

The bottom line of this massive industry is to reach out to the end users with a quality product in quickest possible time to reduce downtime and increase productivity, thereby giving profitability for everyone concern.

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