Tonneau covers are not only used to curb the theft of truck cargo, they also protect both the truck bed and cargo from the elements, especially water, and as such, must be checked for leaks often. While there are many common problems with tonneau covers, leaking is the most dominant.
Is my tonneau cover leaking? If so, where exactly is the leakage? Do I have the basic skills required to leak proof a tonneau cover? What sealing options do I have to fix leak in a tonneau cover? You can fix your leaking tonneau cover as a DIY. However, if you are unsure of what to do next when it comes to fixing the tonneau cover, you may want to consult a professional.
Fixing a leaking tonneau cover can be done using silicone, rubber strips, caulking strips, or vinyl foam tape. These seals are ideal for incidental gaps which occur between any two opening components, in this case, the tonneau and the truck’s side panels.
How to find and fix a leak in a tonneau cover
Follow these steps to find a fix a leak on your tonneau cover.
- Close the cover all the way while leaving the truck’s tailgate open.
- With a second person’s help, use a garden hose to simulate rain or water from a car wash by spraying the water in an upwards motion over the tonneau such that it falls over it naturally. (You can clean the tonneau cover while at it)
- Step three can be one of two options; Use a flashlight to check inside the truck bed to see where the water seeps in or line the truck bed with cardboard or newspapers before step one of this process. This absorbent material will show you exactly where the water drips in and sets once it leaks in.
- On the cover, mark the exact spots where you noted leakage using a marking pen or tape.
- To avoid making any mistakes that may tamper with the final fit of the tonneau cover over the truck afterwards, measure the area where the leakage has been noted. This step is especially important for leakages between the tonneau cover and the truck panels as you will need to completely remove the tonneau cover from the truck to work on it.
- If the leakage is found to be along the perimeter of the tonneau cover, you will need to use either silicone or cut strips of the seal of your choice that perfectly fit the leak but extend all the way along the length or the cover. This will ensure that you do not plug one leak and create a bigger one along the panels. If the leakage was found on the body/surface of the cover, you can fill in the hole/gap with silicone or even as a temporary measure duct tape.
- Once done, replace the cover and test for leakage again. Repeat the process as needed.
The process of how to fix a leaking hard folding tonneau cover made of fibreglass panels is a bit more complicated and is best left up to a professional. It requires a kit comprising of polyester resin, a hardener and a cloth for structural strength. The resin and hardener are mixed and spread over the cracked surface using a disposable brush.