How to Fix a Leaking Tonneau Cover

How to Fix a Leaking Tonneau Cover

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Tonneau covers are an essential part of any truck owner`s day, whether you are driving under the hot sun in the summer or snowy winter. The main issue is that most Tonneau covers are either made of polyester or vinyl, which is not scratch-proof and sometimes, not fully waterproof. Sometimes, the padding or the seal on the side may be insufficient, leading to leaks through the sides of your bed cover; That doesn’t necessarily make it useless. To avoid coughing out more cash every time you notice a soggy spot in your cargo, you have to learn how to fix a leaking Tonneau cover.

Using this DIY method to cover leaking spots on your cover is way cheaper, and it may give you a few more years of service if you use the right material and do it right. In this guide, we have put together a step by step process that will help you make your Tonneau cover leak-proof in a short time.


What You Need to Fix a Leaking Tonneau Cover

  • Install Water Pipes For Draining

One of the most standard solutions for a tonneau cover leaking on the sides is to install water pipes fitted with rubber insulation on the sides. Usually, they already have slits and adhesives at the sides for immediate covering of the gaps. You can also combine as many as you need covering from top to bottom.

The pipes also make the bed cover firm allowing excess water to drip, preventing stagnation, which is the main cause of most leaks. They can be bought on Amazon or visit your local store and look for one that best fits your tonneau cover. They are also compatible with both rolled and folded tonneau covers.

  • Installing extra Seals

This is another simple way to cover leaks on the side of your tonneau cover, especially if the leaks are minimal. Buy the cover seals that resemble or look compatible with your current seal then install it on the source of the leaks. Extra seals are, however, not the best option if you are dealing with large holes as they may lead to more leaks.

  • Bed seal kits

The bed seal kits keep your cargo bed conditioned. They are a package of everything you need to keep the water contained as they come in packages that have seals, foam blocks, and straighteners for the tonneau cover. It does not only protect your tonneau covers from rain but also from snow and dust. It is costlier than the other two but more effective. Some kits may include a drainage system that keeps water from gathering behind your truck.


Step by Step Guide for Fixing Leaks on a Tonneau Cover

  • 1. Find the leak

This is the most crucial step in taming leaks on a tonneau cover. You may need an extra hand to identify precisely where the water is coming through. There are two ways of identifying leaking spots.

  • Fake Rain Method

This is very easy as long as you have a gardening hose with water supply.

  1. Put dry cardboard on the lining of your cargo bed
  2. Completely cover the cargo bed including the tailgate
  3. Sprinkle water on top of the tonneau cover mimicking rainfall without pressurizing it.
  4. Open the cover and find where the leaks are by identifying wet spots on your dry cardboard.

Once you are done, mark those leaking spots with a tape or a bright marker. This method is excellent as it helps you locate even the tiniest leaks in the tonneau cover

  • Daylight Examination

  1. Pack your truck in an open space under bright sunlight.
  2. Close the tonneau cover to the back
  3. Get help in closing the tailgate while inside your cargo bed
  4. Examine any spots that allow light to flood into the cargo bed

This is a great method for spotting leaks in a snap and rolled tonneau covers. You can also identify any wide scratches in the fabric. It is, however, not effective in identifying the smallest leaks.


  • 2. Sealing Off Leaks On A Tonneau Cover

Leaks are best stopped if covered from the top of the cover rather than the bottom. You should also ensure that the sealing material holds evenly onto the lining of the bed cover to prevent water from seeping past the seal itself.

  • Measure the sizes of the spots to find the material that best seals it off
  • Carefully stick the seals or the insulation pipes over the leaking spots if the leaks are coming from the sides.
  • You can stick waterproof adhesive tape on scratches and tears in the fabric of the tonneau cover


  • 3. Test and Repeat

You have to test your seals to ensure they work perfectly. We highly encourage using water to do the tests to be sure it won’t leak the next time you drive in the rain.

  • Once all the identified leaks are covered, cover the cargo bed and test it out using any of the two leak identification methods
  • Repeat the process if needed if there are any more leaks

If you keep finding leaks in the tonneau cover after performing the procedure, you can employ professional help or invest in another tonneau cover.


Final Thoughts

A tonneau cover is a must-have fixture for a truck. It is invaluable in keeping your cargo safe from harsh weather and prying eyes, but it only serves you best if it is waterproof. Having a leaking tonneau cover can is a disappointing experience, especially if you carry water-sensitive cargo. A few leaks on the cover are, however, not the end of its valuable service, all you have to do is buy the right sealing material, trace the leaking spots then seal them off. This guide has all the details you need to renew the waterproof properties of your tonneau cover.

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