Why Do Hydraulic Hoses Fail in Winter?
As temperatures drop, hydraulic systems face additional challenges that can affect performance, reliability and the lifespan of components. Cold weather can make hoses less flexible, increase hydraulic oil viscosity and expose weaknesses in existing equipment.
For agricultural machinery, construction equipment and industrial applications, a failed hydraulic hose can result in unexpected downtime and costly repairs.
Understanding the main causes of winter hydraulic hose failures can help you identify potential problems early and prepare your equipment for colder conditions.
Loss of Rubber Flexibility
One of the main challenges for hydraulic hoses in cold weather is reduced flexibility. Rubber and other elastomeric materials become stiffer as temperatures fall, although the extent depends on the material and hose construction.
At extremely low temperatures, some materials approach their glass transition temperature, where they lose much of their elasticity and become increasingly brittle. For certain materials, this transition can occur around -40°C, but the precise temperature varies.
When a hose becomes stiff, it cannot flex as easily during normal machinery movement. Bending, twisting or vibration can put additional stress on the material, potentially contributing to fine cracks, splitting or premature failure.
How to reduce the risk:
Check that hoses are suitable for the minimum temperatures in which your machinery operates.
Avoid sharply bending, twisting or forcing cold hoses into position.
Inspect hoses for cracking, stiffness and other signs of deterioration.
Follow the hose manufacturer's temperature and installation recommendations.
Choosing the correct hose for the application is particularly important for machinery that regularly operates outdoors during winter.
Thickening Hydraulic Fluid and Increased Viscosity
Hydraulic oil becomes more viscous as temperatures fall, meaning it becomes thicker and more resistant to flow.
When machinery starts in cold conditions, the pump may struggle to draw oil through the suction lines and filters quickly enough. This can contribute to restricted flow, sluggish operation and cavitation, where vapour bubbles form and collapse within the fluid.
Excessive cold-start viscosity can also affect lubrication and place additional strain on pumps and other hydraulic components. Although this does not automatically cause a hose to fail, problems with pressure, flow and system operation can increase the risk of wider equipment damage.
How to reduce the risk:
Use hydraulic oil that meets the machinery manufacturer's viscosity and temperature requirements.
Allow the hydraulic system to warm up according to the manufacturer's instructions before applying heavy loads.
Investigate unusual pump noises, slow operation or unexpected pressure changes.
Check filters and suction lines if the system struggles to draw oil in cold conditions.
Never assume that a higher-viscosity oil is automatically better. The correct specification depends on the equipment and its operating conditions.
Changes in Hose Fittings and Connections
Hydraulic hoses rely on correctly matched fittings, secure connections and suitable seals to contain fluid under pressure.
Metal components and hose materials respond differently to changes in temperature. However, temperature changes alone do not necessarily cause fittings to loosen or leak. Existing wear, damaged seals, incorrect installation and unsuitable components can all contribute to connection problems.
Cold weather can expose these weaknesses, particularly when equipment is started and operating temperatures begin to change.
Signs of a potential problem include:
Hydraulic oil weeping around a fitting.
Visible damage or corrosion on metal connections.
Damaged or deteriorated seals.
Movement or damage around a hose connection.
How to reduce the risk:
Inspect hose assemblies and connections regularly, particularly before winter working periods. Ensure replacements use compatible fittings and are assembled correctly for the system's pressure and application.
Never attempt to tighten or disconnect a hydraulic fitting while the system is pressurised. Hydraulic systems must be safely isolated and depressurised in accordance with the manufacturer's procedures before maintenance.
Ice and Water Contamination
Water contamination is another potential problem during winter. Moisture can enter hydraulic systems through condensation, contaminated fluid, damaged seals or other routes.
When temperatures fall below freezing, free water within a system can form ice. Ice crystals may restrict filters, valves and narrow passages, interfering with fluid flow and potentially contributing to pressure problems or component damage.
Water contamination can also encourage corrosion and affect the performance and service life of hydraulic components, even when temperatures remain above freezing.
How to reduce the risk:
Check hydraulic oil for signs of contamination, following the manufacturer's inspection procedures.
Keep stored hydraulic oil clean and properly sealed.
Maintain reservoir breathers, seals and other components that help prevent contamination.
Investigate unusual system behaviour rather than continuing to operate equipment with a suspected blockage or fluid problem.
If water contamination is suspected, have the system assessed and the fluid dealt with in accordance with the equipment manufacturer's recommendations.
External Physical Damage from Winter Conditions
Hydraulic hoses can also be damaged by their working environment. Snow, ice, frozen debris, mud and other materials may collect around exposed hose assemblies or moving machinery.
Hoses that are unsupported or incorrectly routed can rub against surrounding components, become snagged or experience repeated abrasion. Ice and debris may make these problems worse, particularly when machinery operates in demanding outdoor conditions.
Over time, damage to the outer hose cover can expose the reinforcement or weaken the assembly, increasing the risk of failure.
How to reduce the risk:
Check that hoses are routed correctly and secured where necessary.
Look for rubbing, cuts, abrasion and exposed reinforcement.
Remove accumulated debris safely when equipment is shut down and isolated.
Ensure hoses have sufficient clearance throughout the machinery's range of movement.
Regular inspections are particularly important for agricultural and construction machinery that operates in muddy fields, on building sites or in other exposed environments.
How Can You Prevent Hydraulic Hose Failures This Winter?
Although cold weather cannot be avoided, sensible maintenance can help reduce the risk of unexpected hydraulic problems.
Before winter sets in, consider the following checks:
Inspect hose condition: Look for cracks, leaks, bulges, abrasion and damaged fittings.
Check hydraulic oil: Ensure the fluid meets the manufacturer's specifications for the expected operating temperatures.
Examine hose routing: Make sure hoses are not twisted, stretched, sharply bent or rubbing against other components.
Check for contamination: Follow the recommended procedures for inspecting oil and maintaining clean hydraulic systems.
Warm up equipment correctly: Follow the manufacturer's cold-start instructions before putting machinery under heavy load.
Address problems early: Investigate leaks, unusual noises, sluggish operation and unexpected pressure changes before they lead to more serious damage.
Never search for a high-pressure hydraulic leak with your hands. Escaping fluid can penetrate the skin and cause serious injuries. Suspected leaks should be investigated using appropriate safe procedures by a competent person.
When Should a Hydraulic Hose Be Replaced?
A hydraulic hose should be assessed if it shows visible damage, leakage, deterioration or signs that it is no longer suitable for its application.
However, not all hose damage is visible from the outside, and appearance alone cannot establish whether an assembly is safe to use. Follow the manufacturer's inspection and replacement guidance, and seek professional advice if you are unsure about a hose's condition.
Replacing a damaged hose before it fails completely can help reduce unexpected downtime and the risk of further equipment damage.
Hydraulic Hose Repairs at Suttons Ross
At Suttons Ross, we understand how important reliable hydraulic equipment is to keeping machinery and businesses running smoothly throughout the year.
Our workshop provides hydraulic hose services, repairs and technical support for customers across a range of industries. We can make hydraulic hoses while you wait, helping you obtain a replacement when you need one.
Whether you need a replacement hose, hydraulic components or advice about a repair, our team can discuss your requirements.
