Hydraulic seals play a vital role in pumps and motors, but they can fail due to a wide range of reasons, leading to further component issues. Understanding the root causes of hydraulic seal failure can help steer you in the right direction toward fixing the problem.
At CJ Plant, our team performs repairs on hydraulic systems and seals, and we come across these top 5 causes of seal failure often. We’re here to explain the causes of faulty hydraulic seals in detail.
The Importance of Hydraulic Seals
Hydraulic seals play a critical role in maintaining the performance and reliability of hydraulic systems. A hydraulic seal’s primary purpose is to prevent fluid leakage while retaining pressure within the system, ensuring smooth and efficient operation.
By sealing gaps between moving components, such as pistons and cylinders, they help maintain consistent force and motion. Hydraulic seals are closely linked to the functioning of hydraulic pumps and motors, as these components rely on pressurised fluid to generate power. Without effective sealing, pressure loss can occur, reducing the system’s ability to transmit energy.
Seals not only help prevent fluids from escaping, they also prevent contaminants entering the system too. Seals help prevent dust and debris out of the system, protecting internal components and extending the lifespan of pumps, motors and other hydraulic equipment.
How Hydraulic Seals Affect the Machinery System
Hydraulic seals have a direct impact on the overall efficiency and performance of machinery systems used across different sectors like construction, agriculture, civil engineering and groundworks.
When seals work properly, they maintain optimal pressure levels so hydraulic pumps and motors can operate at peak efficiency. However, seal failure caused by wear, improper installation or extreme operating conditions can lead to fluid leaks and pressure drops. This reduces the effectiveness of energy transfer within the system, forcing pumps and motors to work harder to achieve the same output.
Over time, this increased strain can lead to overheating, higher energy consumption and accelerated component wear. Compromised seals may also allow contaminants to enter the system, further damaging internal parts and reducing operational efficiency.
Hydraulic Failure Causes
Let’s break down the top causes of hydraulic seal failure in more detail.
1. High Temperatures
Hydraulic seals have to be malleable, with the material being shaped without cracking to effectively prevent leaks and contamination. It’s important to have the right material that’s compatible with the system’s operating temperatures and fluid type. Polyurethane (PU/TPU) seals are suitable for high pressure systems, nitrile rubber (NBR) seals are best for systems with hydraulic fuels working at moderate temperatures, while fluoroelastomer (FKM) seals are ideal for systems with temperatures up to 200°C.
High temperatures are unavoidable, and excessive heat, especially when the wrong material is used, will lead to the seal becoming hard, cracking and eventually complete failure.
2. Excessive Pressure
Excessive pressure can cause hydraulic seal failure by placing stress beyond the material’s design limits. When pressure is too high, seals may deform, crack or extrude into gaps between components, leading to leaks. This distortion weakens the seal’s ability to maintain a tight barrier, reducing system efficiency. Over time, continuous exposure to high pressure accelerates wear and fatigue, increasing the likelihood of sudden failure. Excessive pressure also generates heat, which further degrades the seal material, shortening the lifespan and compromising overall hydraulic motor and pump performance.
3. Contamination
Hydraulic system contamination can come in several forms. External contaminants include dust, dirt and debris entering through cylinder rod seals and other access points. Worn seals that have degraded over time can release other particles into the hydraulic fluid. Water ingress from internal condensation or external sources can also lead to failure of the hydraulic system. Air can also cause problems, reducing the lubrication of the seal which leads to degradation. The most common signs that your system and seal is contaminated is leakage, scored rods and visible damage like swelling, hardening or broken lips on the seal.
4. Aging and Wear
While excessive heat and pressure fast-tracks hydraulic seal wear, even if your systems are operating at peak efficiency, seals and other components will eventually age and need either repairing or replacing at some point. As seals age, they can harden, crack or lose elasticity, reducing their ability to maintain a tight seal. Regular wear from moving components, such as pistons in pumps and motors, also contribute to surface damage and material thinning. As a result, these components may require more energy to operate and experience increased strain, ultimately reducing system performance and increasing the risk of seal and system failure.
5. Misalignment and Improper Installation
It’s essential the right seal is used and installed and aligned correctly. If the seal has been poorly installed, the lip of the seal can crack and dent, reducing efficiency and leading to contamination. Improper installation results in a snowball effect of issues, whether it hasn’t been fitted properly or the wrong seal material is used. Changing the type of fluid in the hydraulic system could also require a new compatible seal to be installed, and will need to be aligned properly to ensure hydraulic seal failure is avoided.
Hydraulic Pump and Motor Repairs With CJ Plant
Hydraulic seal failure can be a result of several causes. If the seal goes, so can other vital components like hydraulic motors and pumps. If you spot any signs of seal failure, you need to seek professional repair services ASAP. CJ Plant provides comprehensive hydraulic pump and hydraulic motor repair services, that could be a result of hydraulic seal failure.
We can identify the root causes of hydraulic system failure and conduct expert repairs at our dedicated facility, starting every job with a free strip and inspection before providing a no-obligation quote for repair. Call 01527 870 793 or get in touch using our enquiry form to discuss the problems you’re facing with your hydraulic system.