10 things you should never do when your hydraulic fitting leaks.

A leak in a hydraulic system is not just annoying. It is a safety risk, an environmental burden and a direct operating cost. Handling it incorrectly can make the damage worse, create dangerous situations and lead to longer downtime.

In this guide we run through 10 things you should not do when a hydraulic fitting leaks, and what you should do instead to solve the problem safely and correctly.

Quick action plan

Stop the machine and release the pressure in the system.
Never use your hands to search for leaks. Use cardboard, paper board or leak detection spray.
Clean the area and identify the actual source of the leak.
Replace defective parts (incl. O-ring) with the correct type and standard.
Tighten only to the manufacturer's specifications.
Test for tightness at low pressure before full operation.
Document the cause, the repair and the preventive measures.

10 things you should never do when your hydraulic fitting leaks

1. Do not use your hand to check for leaks
Hydraulic fluid can be extremely hot and under very high pressure. Even small pinhole leaks can inject fluid into the skin and cause serious injury. Always use cardboard, paper board or leak detection spray and never your hands, not even with gloves.

2. Do not tighten the nut indiscriminately Overtightening is one of the most common causes of leaks. It can damage the fitting, the seating surface or the seal and make the problem worse. Assess the connection first and tighten only to specification.

3. Do not let the system operate under pressure
The pressure must always be released before inspection. Even a slow drip can be dangerous if the system is still under load.
Be aware that residual pressure may be trapped in hoses and components.

4. Do not use an almost identical fitting
Fitting something that merely looks similar to save time or money is a classic mistake. Lack of compatibility often leads to repeated leaks and extra downtime. Always replace with exactly the same type, standard and dimension. Guide to identifying thread types.

5. Do not assume the leak is where it drips
Fluid often runs to the lowest point of the system before it drips. The visible drip is therefore not necessarily the actual source of the leak. Follow the oil traces back to the source.

6. Do not reuse O-rings
O-rings degrade over time and may have microscopic cracks that impair the seal. O-rings must always be replaced when a connection is dismantled, even if the rest of the assembly is reused.

7. Do not forget to protect the system during repair
Open ends and dismantled components are highly sensitive to dirt. A dropped fitting can quickly contaminate the system. Always cover open lines and components.

8. Do not forget to clean the connection ends
Dirt and metal shavings can enter the system and damage valves, pumps and cylinders. Always clean threads, mating surfaces and ends before assembly.

9. No open flames or ignition sources
Pinhole leaks can create a fine mist of flammable vapours. Cigarettes, lighters, welding or cutting torches nearby can pose a serious fire hazard. Keep all ignition sources away from the leak area.

10. Do not ignore it
Even small leaks are often a sign of an underlying problem and almost always get worse over time. The sooner the problem is solved properly, the lower the risk, cost and downtime.

Typical causes of leaks

Overtightening.
Under-tightening.
Incorrect thread or standard.
Worn or damaged O-ring.
Vibration or lack of support.
Contamination in the system.

Safety, environment and documentation

High-pressure penetration of the skin requires immediate medical attention.
Hydraulic oil must be collected and disposed of correctly.
Document the incident, the repair and the preventive measures.

Fast help and spare parts

Hymatik has more than 7000 item numbers in stock at our store in Odense SØ, and in addition we have access to over 100,000 item numbers in stock in Germany with fast delivery and international shipping.
If you need fittings, O-rings, hoses or technical advice, you are welcome to contact us.

Phone: 63 12 83 00
Mail: ps@hymatik.com