Monday, September 26, 2022


RV underbelly leak repairs can be a nightmare, but this will help

One of the most frustrating things for an RVer is having to deal with a leak underneath the RV in the underbelly area! If you didn’t know, this is a dreaded repair for any RV technician. As you will see in the pictures below, there is a mess of wires and plumbing that we have to contend with when trying to pinpoint the leak. RV underbelly leak repairs can be like looking for a needle in a haystack.

Contributing factors that can cause an underbelly leak

  • Supply lines could have been improperly run and not secured into place.
  • Road vibration and flex, causing wear and tear/rubbing underneath the unit.
  • Normal use from the water pump causing vibration.
  • Improper use by not using a water pressure regulator.

Why is this repair such a nightmare?

  • On average there are 200+ water line connections throughout the unit.
  • Heat ducting and electrical wiring is often in the way.
  • In most cases, we also have to pull LP lines, power/manual leveling jacks and/or styrofoam around pipes in order to inspect an area and make repairs.

If you are experiencing a leak, there is some helpful information that you can provide that will save your technician some time, which will also hopefully help save your pocketbook:

  • Is the leak from the black, gray or fresh water tank?
  • Is the leak hot or cold water?
  • Was the tank overfilled or is it a drain valve leak?

Knowing this information will help locate the leak faster.

Finally, should you end up in a position of needing an underbelly leak repair, whether it is you or an RV technician, this is your golden opportunity to do the following while having the underbelly removed:

  • Add additional insulation.
  • Add more spray foam where needed. This will help seal off any penetrations from the floor to the house which will help reduce the interior heat or cooling loss. In addition, this will also help reduce the path of entry for pests, rodents, and dust/dirt.
  • Secure all water lines and electrical wiring that is floating around to help prevent future leaks.
  • Secure and retape all heat ducts and piping.

If you are doing these repairs yourself, here are some links to items you’ll need to complete the job:


If you missed Dustin’s post on Tuesday, “Keep this product on hand for easy RV underbelly repair,” you’ll want to read it here.

Make sure you check out Dustin’s website, California RV Specialists, and their YouTube channel for more helpful information.



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1 month ago

Total lack of engineering. The manufacturers evidently do not care about quality or longevity of their product. What I’ve seen in the pictures could have been easily avoided. :You don’t see this kind of mess in buildings, autos, or farm equipment.

1 month ago

Based on the photos and my own experiences I would say poor design, sloppy assembly and no quality control are the root of most of these type problems. The RV industry is a disaster.

1 month ago

If you do the calculations for the underbelly tape on Amazon, $54.99 div by 20 feet is not $3.01/meter. $54.99 div by 20 is $2.75/foot or $9.02/meter.

1 month ago

I’d try to fix it myself. If a water leak happened under there I’d probably pay half of the trailers value for someone else to fix it.

1 month ago

I would also lubricate any concealed black and gray tank valves.

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