Rebuilt Hydraulic Cylinders: Can They Have Shorter Strokes?

Rebuilding a hydraulic cylinder is a highly technical process that requires advanced knowledge and special tools. It involves disassembling the cylinder, inspecting and replacing worn or damaged components, and reassembling it. While it may be tempting to rebuild a hydraulic cylinder to save costs, there are hidden costs and considerations to take into account, such as extended equipment downtime and the need for specialized tools and knowledge. In most cases, the more cost-effective and long-term solution is to purchase a replacement hydraulic cylinder.

One common question that arises when modifying equipment that uses hydraulic cylinders is whether it is acceptable to short stroke a hydraulic cylinder, i.e., use it without allowing it to reach its full retraction or extension. While there is no definitive answer, some engineers suggest that it is generally not advisable to rely on the cylinder itself as a hard stop and that it is better to use external structural stops to limit travel. Additionally, it is recommended to keep within 80% of the maximum stroke to ensure better stability and prevent damage from side loads.

Shortening the stroke of a hydraulic cylinder can be done by disassembling it and using a spacer or washers

Shortening the stroke of a hydraulic cylinder is possible and can be done through various methods. One way to achieve this is by disassembling the cylinder and using a spacer or washers. This method involves removing the cylinder's linkage and taking it apart to access its internal components.

For a single-ended ram cylinder, the process begins by removing the snap ring from the end of the housing and pulling out the rod. The nut is then taken off the rod's end, and a spacer or multiple washers are inserted between the bushing and the nut. The spacer's thickness determines the desired shortening of the stroke. After reassembling the cylinder, the mounting tab on the tierod needs to be adjusted. This method is most effective if the cylinder has not yet been mounted on a vehicle.

For a double-ended cylinder, the process involves disassembling the cylinder, removing the gland with seals, and creating two spacers of equal thickness. These spacers are placed on each side of the cylinder during reassembly. This technique has been observed in factory tractors and aerial equipment.

When using a spacer or washers to shorten the stroke, it is crucial to ensure that the internal diameter (ID) of these components matches the outer diameter (OD) of the ram shaft for a precise fit.

Another approach to shortening a hydraulic cylinder involves cutting and rewelding. This method is more complex and requires determining the desired length by considering the stroke and the depth of the piston. The base plate is cut off, and the barrel is trimmed to the correct length. The base plate is then rewelded to the end, ensuring everything remains square to prevent distortion. If the inlet port is separate from the base plate, it must be welded separately, being cautious not to distort the cylinder.

While cutting and rewelding can be done in a machine shop for precision, some individuals opt to perform this process in the field using a torch, welder, and grinder. However, it is essential to be cautious and consider seeking professional assistance to ensure the job is done correctly and safely.

The spacer method involves measuring the desired distance to be shortened and creating a spacer with the same ID as the ram shaft's OD

When modifying an existing mast/boom design, it is desirable to keep the existing cylinder to avoid having to stock two different cylinders. However, this can lead to concerns about the cylinder not being able to "bottom out" on full retraction. One solution to this problem is to use the spacer method.

The spacer method involves measuring the desired distance to be shortened and creating a spacer with the same inner diameter (ID) as the outer diameter (OD) of the ram shaft. This spacer is then placed inside the cylinder, effectively reducing the stroke length by the thickness of the spacer. It is important to note that this method may require disassembling the cylinder and making adjustments to the mounting tab.

The spacer method can be a simple and effective way to shorten the stroke of a hydraulic cylinder. However, it is important to consider the potential impact on the performance and stability of the system. Any modifications should be made with careful consideration and expertise to ensure safety and avoid damage to the equipment.

Additionally, when using hydraulic cylinders, it is generally recommended to stay within 80% of the maximum stroke to ensure better stability and prevent damage from side loads. It is also important to consider the application and requirements of the cylinder, such as the available space, accuracy, control, load holding, weight capacity, and mounting options.

In summary, the spacer method can be a viable approach to slightly shortening the stroke of a hydraulic cylinder, but it should be approached with caution and a thorough understanding of the system.

Alternatively, one can use multiple washers to achieve the same effect

If you need to shorten the stroke of a hydraulic cylinder, one method is to disassemble the cylinder and use multiple washers with the correct ID (inner diameter) to reduce the stroke length. This method can be used for both single and double-ended cylinders.

For a single-ended ram, you can pull the snap ring from the end of the housing and remove the rod. Then, take off the nut from the rod's end and insert a spacer or multiple washers between the bushing and the nut. Finally, reassemble the cylinder.

For a double-ended cylinder, disassemble the cylinder and remove the gland with the seals. Make two spacers of the desired thickness and put one on each side of the cylinder before reassembling. If the cylinder is short, you may need to use a stick welder to tack the spacer in place. Alternatively, you can remove the gland holding the seals and place a spacer there instead.

Using washers or spacers to shorten the stroke of a hydraulic cylinder is a common practice in factory tractors and aerial equipment. It is important to note that altering the cylinder's stroke can affect its performance, so it should only be done if necessary and with careful calculations to ensure the cylinder still operates within safe parameters.

It is important to note that this process should be done with caution, as improper sizing can lead to issues

Rebuilding a hydraulic cylinder is a highly technical process that requires caution. Improperly sized seals, incorrectly installed components, and other defects can lead to a range of issues, from reduced performance to catastrophic shutdown, injury, or further damage to the cylinder.

When rebuilding a hydraulic cylinder, it is crucial to follow the correct procedures and possess the necessary knowledge and tools. Firstly, you must identify any wear, damage, or contamination through a thorough inspection of the cylinder. This includes checking all seals, components, and fluids. Once the issues have been identified, you will need to source the appropriate replacement parts and tools, as well as prepare a clean and organised workspace.

The next step is to carefully remove the cylinder from the machinery and disassemble it. This should be done with caution, as incorrect disassembly can lead to damage. After disassembly, replace all worn or damaged components, following the instructions provided by the manufacturer. Reassembly should also be approached with caution, as incorrect installation can lead to issues.

Once the cylinder has been reassembled, rigorous testing is essential to ensure the rebuilt cylinder functions correctly and safely. Finally, the cylinder can be reinstalled into the machinery.

It is important to note that rebuilding a hydraulic cylinder may not always be the best option. In some cases, it may be more cost-effective and efficient to purchase a new cylinder, especially if you lack the necessary tools, knowledge, or experience. Rebuilding a hydraulic cylinder also requires extended equipment downtime, which can impact operations. Therefore, it is crucial to carefully consider the advantages and disadvantages of rebuilding versus replacing before proceeding.

When in doubt, it is best to consult a professional or refer to the manufacturer's instructions

Rebuilding a hydraulic cylinder is a highly technical process that requires advanced knowledge and specialised tools. While it may be tempting to attempt a rebuild yourself, consulting a professional or referring to the manufacturer's instructions is always best to ensure safety and avoid further issues.

When rebuilding a hydraulic cylinder, it is crucial to identify the type of cylinder you are working with. The three main types are piston rod cylinders, plunger cylinders, and telescopic cylinders. Each type has unique features and requirements that must be considered during the rebuild process. Attempting to rebuild a cylinder without this knowledge can lead to costly mistakes and further damage.

Additionally, it is essential to have the necessary tools and workspace for the job. Honing machines, hydraulic presses, and pullers are just some of the specialised equipment needed. Without these tools, the rebuild process can be challenging, and the risk of improper installation or damage increases significantly.

Moreover, the process of rebuilding a hydraulic cylinder involves several intricate steps, from disassembling and inspecting the cylinder to replacing worn components and reassembling it. Each step must be executed with precision to ensure the cylinder's optimal performance and longevity. A minor mistake or oversight can have significant consequences.

Furthermore, there are safety considerations to keep in mind when working with hydraulic cylinders. Improperly sized seals, incorrectly installed components, or overlooked defects can lead to catastrophic failures, injuries, and costly shutdowns. It is always better to seek professional assistance than to risk your safety and the integrity of the equipment.

While upfront costs may seem higher when seeking professional help or purchasing a new cylinder, it can ultimately save time and money. Rebuilding a hydraulic cylinder yourself may lead to extended equipment downtime, hidden costs, and the need for specialised tools. Weighing the benefits of professional assistance or a new cylinder against the potential drawbacks of a DIY rebuild is essential for making an informed decision.

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