Read the manual thoroughly and understand all of the instructions, cautions, and warnings before using this equipment. If any section of the manual is not understood, contact your nearest authorized dealer, or contact Generac Customer Service at 1-888-436-3722 (1-888-GENERAC), or www.generac.com with any questions or concerns.
Fuel System Leak Test
It is crucial to perform a fuel system leak test before the startup of a home standby generator and after any service work is done on the fuel system (for example, sediment trap cleaning). It is also best practice to include a leak test during scheduled maintenance.
Generator owners should reference these articles prior to performing a fuel system leak test:
Maintenance Schedule
Performing a fuel system leak test is listed as part of a home standby generator's maintenance schedule in the owner's manual. Where can I find a user manual or other documentation for my home standby generator?
Maintenance Safety
Owners should reference What Safety Precautions Should I Take When Performing Maintenance on My Generator? before maintenance is performed to ensure the maintenance is performed safely.
Authorized Service Dealers
While owners may perform maintenance tasks, Generac recommends consulting with your local Independent Authorized Service Dealer (IASD). See the How Can I Find a Generac Service Dealer in My Area? article for more information.
Environment
This article applies to most air-cooled home standby generators.
Note: The images below may not represent your specific model. Always check your generator's user manual for appropriate maintenance procedures.
When should a fuel system leak test be performed?
All products are factory-tested before shipping to verify the performance and integrity of the fuel system. However, it is important to perform a final fuel system leak test before the startup of a home standby generator. Generac strongly recommends this inspection be performed by a certified service dealer (IASD) or authorized professional. See the How Can I Find a Generac Service Dealer in My Area? for more information.
Additionally, it is best practice to perform a fuel system leak test during normally scheduled maintenance. See the Where Can I Find the Maintenance Schedule for My Generac Home Standby Generator? article for more information.

Before you begin (pre-test checks)
- Initial assessment: Look for wet spots or puddles, a strong fuel odor, discoloration or stains, unexplained drops in fuel level, performance changes, excess fumes, or audible hissing near fuel lines.
- Surface prep: If a leak area is suspected, clean the surface so fresh bubbles are easier to see during the test.
- Flexible fuel lines: Inspect interior flexible lines for cracks, kinks, abrasion, or loose clamps. Correct or replace as needed before testing.
Tools needed
- Non-corrosive gas leak detection fluid (spray or dauber)
- Electronic leak detector (optional, to supplement the liquid test)
Performing a fuel system leak test
Inspection for leaks should be done at every connection point from the generator to the supply source.


- Prepare the unit safely. Ensure the generator is off and safe to service. Work in a well-ventilated area away from open flames or sparks.
- Pressurize the system as required by local code/procedure for your installation.
- Apply non-corrosive gas leak detection fluid to each connection (threaded joints, unions, regulators, sediment trap fittings, interior line connections, and service valves). The solution should not be blown away or form bubbles under normal conditions.
- Observe for bubbles. Persistent bubble formation indicates a leak. Mark the location for repair. An electronic leak detector may be used to help pinpoint very small leaks.
- If a leak is found: Shut off the fuel supply and ventilate the area. Tighten, reseal, or replace the suspect fitting/component per code and manufacturer guidance. After corrections, retest the connection to verify the leak is resolved.
The test will identify possible leaks at all connection points (A).

After you’re done
See also