A leaking hydraulic cylinder does not always mean the entire cylinder needs to be replaced. If the rod, barrel, piston, and other major components remain in good condition, replacing the worn seals may restore reliable operation and extend the cylinder’s service life.

The process, though, is not identical for every cylinder. The correct disassembly sequence, seal arrangement, and reassembly method depend on the cylinder’s design. That is why seeing the repair performed can be much more useful than trying to follow written instructions alone.

Bailey’s hydraulic cylinder seal replacement video series provides step-by-step demonstrations for several common cylinder styles, helping you see how each assembly comes apart and how the new seals should be installed.

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When Should You Replace Hydraulic Cylinder Seals?

External leakage around the cylinder rod is the most obvious sign of seal wear, but other symptoms may include:

• Cylinder drift
• Weak or inconsistent movement
• Reduced ability to hold a load
• Jerky operation
• Recurring loss of hydraulic fluid
• Visible deterioration around the rod wiper

Make Sure the Cylinder Is Rebuildable

New seals cannot compensate for damaged metal surfaces.

Before completing the repair, inspect the cylinder rod, barrel, gland, and piston for:

• Deep scoring
• Pitting or corrosion
• A bent rod
• Damaged threads
• Excessive wear
• Cracked or distorted components

A damaged rod or bore can quickly destroy the replacement seals. Depending on the severity of the damage, the cylinder may require professional repair or complete replacement.

Start with the Correct Seal Kit

Two cylinders with similar dimensions may still use different seal profiles, materials, or internal arrangements. Whenever possible, use the cylinder’s complete model or part number to identify the correct replacement kit.

Before removing the old seals, take photographs of their locations and orientation. Many hydraulic seals are directional, meaning they must face a specific way to contain pressure properly. Installing one backward can cause the cylinder to leak or perform poorly immediately after the rebuild.

Remember, Bailey offers a broad selection of hydraulic cylinder seals and seal kits for common Chief, Maxim, and other cylinder designs.

What Does the Seal Replacement Process Involve?

Although the exact procedure varies, most cylinder re-sealing projects include the same general stages:

1. Clean the cylinder before opening it.
2. Remove the gland and rod assembly.
3. Disassemble the piston, gland, and related components.
4. Remove and document the old seals.
5. Inspect the rod, bore, piston, and gland for damage.
6. Install the new seals in the correct locations and orientation.
7. Reassemble and reinstall the cylinder.
8. Cycle and test the cylinder gradually.

Each of these steps contains details that are easier to understand visually. For a closer look at the process, watch Bailey’s complete How to Change Hydraulic Cylinder Seals video series.

Safety and Cleanliness Matter

Hydraulic systems may retain dangerous pressure after the equipment is shut down. Before disconnecting a cylinder, lower all attachments, isolate the power source, relieve trapped pressure, and follow the equipment manufacturer’s lockout/tagout procedures.

Never work beneath a load supported only by hydraulics, and never use your hand to search for a pressurized leak. Hydraulic fluid injected beneath the skin is a medical emergency.

Cleanliness is equally important. Dirt entering an open cylinder can damage new seals and other components as soon as the equipment returns to operation. Clean the outside of the cylinder before disassembly, cap open hoses and ports, and perform the rebuild in a clean work area.

Do Not Ignore Why the Seals Failed

Seals eventually wear, but premature failure usually has an underlying cause.

Common contributors include:

• Contaminated hydraulic fluid
• Excessive heat
• Pressure spikes
• Side loading or misalignment
• A damaged cylinder rod
• Incorrect seal installation
• Incompatible fluid or seal material
• Operation beyond the cylinder’s rated limits

Pay attention to the condition of the old seals during disassembly. Cuts, embedded particles, hardening, uneven wear, or extrusion damage can help identify what went wrong.

Watch the Complete Seal Replacement Process

Written instructions can explain the sequence, but they cannot always show the subtle details that make the difference between a reliable rebuild and a damaged new seal.

Visit Bailey’s hydraulic cylinder seal replacement playlist for practical, step-by-step demonstrations covering common cylinder designs.

Need help finding the right components for your repair? Browse Bailey’s hydraulic cylinder seals and seal kits or contact the Bailey team for assistance identifying the correct kit for your cylinder.

Hydraulic hose routing may look like a minor installation detail. As long as the hose reaches from one connection point to another without leaking, it is easy to assume the job is finished.

But “connected” does not necessarily mean “correctly installed.”

A hose can be the right size, pressure rating, and material for an application, and still fail prematurely because of how it is routed. Excessive bending, twisting, abrasion, heat, poor support, and machine movement can gradually weaken the hose assembly until it begins leaking.

That makes hose routing more than a matter of keeping an installation neat. It directly affects equipment reliability, maintenance costs, operator safety, and hydraulic system performance.

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Here are 10 common routing mistakes that can significantly shorten hydraulic hose life.

1. Installing a Hose That Is Too Short

A hydraulic hose should never be pulled tight between two connection points.

When a hydraulic system is pressurized, the hose may change slightly in length and diameter. Equipment vibration and component movement place additional demands on the assembly. If the hose is already stretched tight, these forces are transferred directly to the fittings and hose reinforcement.

Over time, this can cause fitting separation, connection leakage, reinforcement fatigue, and other issues.

A properly routed hose should include enough slack to accommodate pressure changes, vibration, and movement without becoming fully extended. On a straight run, a slight bend is generally preferable to a hose pulled taut.

However, more hose is not always better. Excessive slack can create loops that snag, rub against nearby components, or enter a pinch point. Additionally excess hose bending creates unneccesary internal friction and heat. The goal is controlled flexibility.

2. Exceeding the Minimum Bend Radius

Every hydraulic hose has a minimum bend radius specified by its manufacturer. This is the smallest radius at which the hose can bend without damaging its internal structure or restricting flow.

Forcing a hose into a tighter bend can distort the tube, shift the reinforcement, and concentrate stress along the inside and outside of the curve. In extreme cases, the hose may kink or partially collapse, restricting hydraulic flow and reducing downstream pressure and increasing upstream pressure.

Improperly installed hose may still function after installation, but its service life can be significantly reduced.

Minimum bend radius should be treated as a limit, not an ideal target. Whenever space allows, use a more gradual curve. If the available routing space cannot accommodate the required bend, an angled fitting or adapter may be a better solution than forcing the hose into position.

Always consult the specifications for the exact hose being installed. Bend-radius requirements vary by hose construction, diameter, and manufacturer.

3. Starting the Bend Too Close to the Fitting

Even when the overall bend radius appears acceptable, a hose can still be damaged if the bend begins immediately behind the coupling.

The section where the hose enters the fitting is already subject to concentrated mechanical stress. Bending sharply at this point adds leverage and repeated flexing to one of the most vulnerable areas of the assembly.

Allow a short, straight section of hose after the fitting, before the bend begins. If the routing direction must change immediately after the port, use an appropriate elbow or angled fitting.

The fitting should help direct the hose into its natural route. The hose should not be forced to compensate for a poorly oriented connection.

4. Twisting the Hose During Installation

Hydraulic hose is designed to bend. It is not designed to operate under continuous torsional stress.

Twisting may happen when one end of the hose rotates during tightening, when the fittings are incorrectly oriented, or when a straight fitting is used where an angled connection is needed. The twist may be difficult to see once the assembly is installed.

Under pressure, however, the hose attempts to return to its natural position. This places uneven stress on the reinforcement layers and can cause the hose to move, buckle, or fatigue during repeated pressure cycles.

A useful installation check is to look at the printed information running along the hose cover, often called a "layline." The layline should remain straight rather than spiraling around the assembly.

When tightening a connection, hold the hose or mating fitting as required to prevent rotation. If the hose cannot reach the port without twisting, stop and correct the routing or fitting orientation.

5. Allowing the Hose to Rub Against Other Surfaces

Abrasion is one of the most common causes of hydraulic hose damage.

A hose does not need to move very far to wear through its outer cover. Small, repeated movements caused by equipment vibration can make the hose rub against metal brackets and frame rails.

Once the cover is worn away, the reinforcement becomes exposed to moisture, corrosion, and physical damage. The hose’s ability to contain pressure may deteriorate even when the assembly has not yet started leaking.

The best solution is to eliminate contact through better routing and support. When contact cannot be avoided, use appropriate protective measures such as abrasion-resistant sleeving, spiral guards, clamps, grommets, or edge protection.

Protection should not be used to justify a fundamentally poor route. A sleeve can slow wear, but it cannot make an uncontrolled rubbing point harmless.

6. Using Too Few Clamps

Clamps help control hose movement, reduce vibration, and prevent contact with nearby components. Without sufficient support, a hose can whip, sag, rub, or be pulled into moving machinery.

By the same token, incorrect clamping can create a different set of problems.

A clamp that is too tight may restrict natural hose movement, crush the cover, or create a concentrated stress point. A clamp positioned directly at a bend may prevent the hose from flexing naturally. Sharp-edged or improperly sized clamps can also cut into the cover.

Use clamps designed for hydraulic hose and position them on relatively straight sections whenever possible. They should secure and guide the hose without flattening it or locking every part of the assembly rigidly in place.

Avoid clamping high- and low-pressure hoses tightly together. Different hoses may change length or move differently during operation, creating friction between their covers.

Good support controls movement. It does not eliminate the small amount of movement a flexible hose needs to absorb pressure changes and vibration.

7. Routing Too Close to Heat Sources

High operating temperatures accelerate hose degradation. Routing a hose near an exhaust system, engine component, hot manifold, furnace, or other heat source can harden the cover, weaken the tube, and reduce flexibility.

Heat exposure is not limited to direct contact. Radiant heat can damage a hose even when there is an air gap between the hose and the hot surface.

Whenever possible, increase the distance between the hose and the heat source. If rerouting is not practical, use a suitable heat shield, barrier, or protective sleeve rated for the application.

Also consider the temperature of the hydraulic fluid itself. A hose exposed to both high fluid temperatures internally and radiant heat externally can deteriorate much faster than expected.

8. Ignoring the Machine’s Full Range of Motion

A hose may look perfectly routed while the equipment is stationary and still be completely wrong once the machine begins moving.

Cylinders extend and retract. Booms raise, lower, and pivot. Steering systems articulate. Attachments rotate. Suspensions travel. Each movement changes the distance and angle between hose connection points.

If routing is evaluated in only one position, the hose may become overly stretched, form a tight bend at full retraction, or enter a pinch point.

Before an installation is approved, slowly cycle the machine through its complete operating range under controlled conditions.

The hose should move in a predictable path without becoming tight, twisted, crushed, kinked, or exposed to damaging contact.

(This step is especially important on mobile equipment, where the hose route may change continuously during operation.)

9. Forcing the Hose to Compensate for Poor Fitting Selection

Routing problems are not always solved by changing the hose. Sometimes the real problem is the connection geometry.

If a port faces the wrong direction or sits in a confined area, forcing a straight hose end into the connection can create an immediate sharp bend or side load. Adding extra hose length may only produce a larger, less controlled loop.

Angled fittings, elbows, swivel connections, and adapters can help. However, adapters should be used deliberately. Every additional connection introduces another potential leak point and may affect space, flow, and maintenance access.

The objective is not to use the fewest fittings at any cost. It is to create a route that protects the hose and connections without adding unnecessary complexity.

10. Treating Routing as a One-Time Installation Decision

Even a well-routed hose requires inspection.

Clamps can loosen, protective sleeves can wear through, and components may shift.  Replacement parts may be installed differently. Operators may add attachments or make field modifications that change how the hose moves.

Unfortunately, hose condition is often evaluated only after a leak appears. By then, the assembly may already be unsafe.

Routine inspections should look for:

• Abrasion or exposed reinforcement

• Cracks, cuts, blisters, or bulges

• Oil seepage

• Kinks or flattened areas

• Loose or damaged clamps

• Corrosion at fittings

• Hose movement near pinch points

• Hardening or heat damage

• Twisting or fitting misalignment

• Changes in the hose’s normal position

Routing should also support maintenance. Hoses need to be visible and accessible enough to inspect and replace safely. A route that hides wear points or requires major disassembly for routine service may later create maintenance problems.

A quick note here – never use your hand to search for a hydraulic leak. High-pressure fluid can penetrate the skin and cause a serious medical emergency. Shut down the equipment, relieve stored hydraulic pressure, and follow the equipment manufacturer’s lockout and service procedures before inspecting or replacing a hose.

Good Hose Routing Protects the Entire System

A hydraulic hose is flexible, but that does not mean it can tolerate every possible route.

Any tight bend, twist, rubbing point, unsupported span, and heat source adds stress. One mistake may not cause immediate failure, which is exactly why routing problems are easy to overlook. The equipment may operate normally for days, weeks, or months while the hose gradually weakens.

Then the failure appears suddenly.

Effective hose routing requires looking beyond whether the assembly reaches its ports. Ask:

• Can the hose move naturally as pressure changes?

• Does it remain protected through the machine’s full operating range?

• Are the bends gradual and away from the fittings?

• Is the hose supported without being crushed or restricted?

• Can maintenance personnel inspect it easily?

A few additional minutes spent evaluating routing during installation can prevent unplanned downtime, hydraulic fluid loss, equipment damage, and safety hazards later.

When selecting or replacing hydraulic components, consider how every part of the system will operate together. Bailey’s hydraulic specialists can help identify components that fit the pressure, flow, movement, and operating conditions of your application.

Even the highest quality cylinder, motor, or pump can't overcome one simple installation mistake: bearing misalignment.

It's tempting to focus on hydraulic pressure, flow rates, or component sizing when troubleshooting equipment performance. But in many cases, the real culprit isn't hydraulic at all. It's a shaft or bearing that's just slightly out of alignment.

A few thousandths of an inch may not seem significant during assembly. Over hundreds of operating hours, however, that small error can translate into vibration, excessive heat, accelerated seal wear, shaft damage, and premature bearing failure.

Bearings are designed to support rotating shafts while minimizing friction. So, when they're properly aligned, loads are evenly distributed across the rolling elements.

This means misaligned bearings create uneven loading, which concentrates stress on one portion of the bearing, instead of distributing it across the entire raceway. The result is higher operating temperatures, increased vibration, lubricant breakdown, and a dramatically shorter service life. Improper mounting practices are a major contributor to premature bearing failures, making installation just as important as bearing selection.  

For mobile hydraulic equipment especially, the consequences can escalate quickly.

Common symptoms include:

• Excessive vibration  

• Bearing noise or squealing  

• Elevated operating temperatures  

• Premature seal failure  

• Shaft wear  

• Increased power consumption  

• Frequent bearing replacement  

Often, technicians replace the bearing without addressing the underlying alignment issue, and the new bearing fails just as quickly.

Static vs. Dynamic Misalignment

Understanding the type of misalignment is the first step toward correcting it.

Static Misalignment

Static misalignment exists before the machine ever begins operating. Common causes include:

• Uneven mounting surfaces  

• Non-parallel bearing housings  

• Incorrect shaft positioning  

• Improper installation procedures  

• Offset mounting holes  

Fortunately, this type of misalignment is usually preventable with careful installation and inspection.  

Dynamic Misalignment

Dynamic misalignment develops while the machine is running.

Potential causes include:

• Bent shafts  

• Structural frame deflection  

• Heavy side loading  

• Excessive operating loads  

• Normal component wear over time  

Because mobile equipment frequently operates under changing loads, dynamic misalignment is often more difficult to diagnose.

‍A Step-by-Step Guide to Proper Bearing Alignment

1. Start with Clean Mounting Surfaces

Before installing anything, inspect every mounting surface for cleanliness and any visible damage.

Remove:

• Dirt  

• Rust  

• Paint buildup  

• Burrs  

• Old gasket material  

Even small contaminants can prevent components from seating correctly and introduce alignment errors before the machine ever leaves the shop. Clean, flat mounting surfaces are one of the simplest ways to improve bearing life.  

2. Inspect the Shaft

A damaged shaft will never produce proper alignment.

Check for:

• Nicks or scoring  

• Bent shafts  

• Excessive wear  

• Corrosion  

• Incorrect shaft diameter  

If the shaft itself isn't true, replacing the bearing alone won't solve the problem.

3. Leave the Housing Slightly Loose During Initial Installation

One common installation mistake is tightening everything immediately.

Instead:

1. Position the bearing on the shaft.  

2. Install the housing bolts finger tight.  

3. Allow the bearing to naturally center itself.  

4. Rotate the shaft by hand.  

5. Tighten the housing only after proper alignment has been achieved.  

This simple practice allows self-aligning bearing inserts to find their natural operating position before everything is locked into place.  

4. Measure Alignment

Don't rely solely on visual inspection.

Depending on the application, technicians may use:

• Straightedges  

• Dial indicators  

• Feeler gauges  

• Laser alignment tools  

For mounted bearings, manufacturers often recommend measuring at multiple points around the housing to verify the bearing is evenly seated and operating within specified alignment limits.  

5. Tighten Fasteners Evenly

Uneven bolt tightening can introduce misalignment.

Follow the manufacturer's torque specifications and tighten mounting bolts gradually using a cross-pattern whenever applicable.

This distributes clamping force evenly across the housing.

6. Verify Rotation Before Startup

Before powering the hydraulic system:

1. Rotate the shaft manually.  

2. Listen for rubbing or binding.  

3. Confirm smooth movement.  

4. Verify there are no tight spots.  

If something doesn't feel right during manual rotation, it almost certainly won't improve once the machine reaches operating speed.

Mistakes That Shorten Bearing Life

Even experienced technicians occasionally make installation errors.

Some of the most common include:

Using a Hammer During Installation

Impact loading can damage bearing raceways before the machine ever runs. Use a press or proper installation tools instead, applying force only to the bearing ring with the interference fit.  

Ignoring Manufacturer Specifications

Every bearing has allowable alignment limits, mounting procedures, and torque recommendations.

Treating every bearing the same often leads to premature failure.

Overlooking the Entire System

Replacing a failed bearing without checking shafts, housing, couplings, or mounting surfaces simply treats the symptom, not the cause.

Preventive Maintenance Goes Beyond Lubrication

Lubrication is essential, but it's only one piece of bearing reliability.

During routine maintenance, inspect for:

• Oil leaks around seals  

• Vibration increases  

• Temperature changes  

• Unusual operating noise  

• Loose mounting hardware  

• Shaft movement  

Finding small alignment problems early can prevent catastrophic failures later.  

Bearing alignment may not receive the same attention as hydraulic pumps, cylinders, or valves, but it has an out-sized impact on system reliability.

A properly aligned bearing helps reduce vibration, extend component life, protect seals, and keep mobile hydraulic equipment operating as intended. Conversely, even a minor alignment error can create a chain reaction of wear that results in costly downtime and unnecessary repairs.

When it comes to hydraulic equipment, reliability isn't determined solely by the quality of the components you install. It depends equally on how well those components are installed in the first place.

Need help selecting the right hydraulic components for your application? Our engineering and technical support teams are here to help.

Contact Bailey International today to discuss your application or explore our full lineup of hydraulic cylinders, pumps, motors, valves, power units, and electronic controls.