Why is the RV Making a Popping Sound?

How to fix the annoying popping noise coming from the RV hydraulic auto leveling system.



2 min read

Walking around the RV inside, we started noticing a popping noise. The new RV sound is reminiscent of popping bubble wrap. We noticed certain areas are more predominant with each light step. At times the sound became a fun game between the two of us. Other times, like trying to sleep at night, the sound was annoying.

Don realized the RV hydraulic auto-leveling system by the Lippert Components Inc (LCI) was creating the popping noise. Hydraulic systems are not cheap, which, worried Melissa, may have a catastrophic failure. Her husband, who worked on helicopter hydraulics, knew the system was not failing. However, the annoying RV popping noise needed investigation.

There is a solution

After extensive internet digging, we found the solution on the LCI website. They allow using an additive rather than replacing all the RV auto-leveling system fluid. LCI has approved* the use of three different brands of anti-stiction:

  • Torco RFF Grade 15

  • Maxima Fork Oil Grade 15

  • Caterpillar Hydraulic Oil Additive 1U-9891

*as of the original blog post date in 2018 

We could only find the Caterpillar Hydraulic Oil Additive 1U-9891 locally. Our town has a Cat dealer where we confirmed the planned use for an RV hydraulic auto leveling system. The best part being the store had some in stock, and we went home with one quart to test. Melissa had doubts something so simple could potentially reduce the RV popping noise.

Skill Level: Beginner

The process of adding anti-stiction fluid into the hydraulic system is relatively simple. Remove one quart of the current hydraulic fluid, then replace it with one quart of the anti-stiction additive. It will not take long to complete the process.

The only skills you need:

  • Removing a reservoir cover with a screwdriver

  • Using a fluid extraction device

  • Manually operate the auto-leveling system 

What You Will Need to Do 

The following is a general outline of the process:

  1. Find a firm level spot to work since you must retract and fully extend the leveling jacks.

  2. Ensure your wheel caulks are in place.

  3. Retract any slideouts and attach the RV to your rig (5th wheels & travel trailers)

  4. Locate the hydraulic reservoir.

  5. Get a disposable 1 quart (32 fluid ounces) or larger sealable container. We used a 1-quart canning jar.

  6. You will need an oil transfer pump to remove the liquid. A turkey baster will work too. Throw the baster away after the project. Otherwise, Thanksgiving dinner may taste weird.

  7. Double-check that there is nothing underneath your RV. Ensure you are 'hitched up.' Now, fully retract the leveling jacks.

  8. With the system fully retracted, remove 1 quart of fluid.

  9. Add ½ of the new fluid, then fully extend all cylinders and jacks.

  10. Add the remaining 1/2 of the new fluid.

  11. Cycle the system two or three times to help mix the fluids.

  12. Set up your RV as you usually would.


After we completed the procedure, a reduction in the amount of RV auto-leveling popping was noticeable. The process is quick, inexpensive, and a beginner do-it-yourself project.


Our RV Life involves many stationary months with the hydraulic jacks deployed. Before the RV popping issues, we were adjusting the auto-leveling system weekly. Being new to RV Life and seeing no hydraulic system leaks, we assumed re-leveling was normal. Once we performed this easy fluid swap, the constant re-leveling was remedied. A bonus outcome indeed!

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