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How To Install Tailgate Seal [Step By Step Guide]

Are you planning to install a truck cap, and do you want to make the truck bed resistant to water and dust by installing a tailgate seal? And do you want to know how to install a tailgate seal correctly? You've come to the right place, for we have researched this question and have the answer!

Here are the steps for installing a tailgate seal on your truck:

  1. Clean the edge of the bed of the car.
  2. Measure the bottom of the bed.
  3. Cut a seal length equal to the size of the bottom of the bed.
  4. Attach the bottom seal to the bottom of the bed.
  5. Cut two seals equal to the height of the sides of the truck bed.
  6. Attach the two seals to the sides of the truck.
  7. Test the seal for leaks.
  8. Finalize the seal installation.

Let's talk more about sealing your tailgate in the succeeding sections. Learn about the complete steps in installing a tailgate seal on your truck in the areas below. Let's dive right in!

Before you continue reading, let us say we hope you find the links here useful. If you purchase something through a link on this page, we may get a commission, so thank you!

What Is A Camper Shell?

A camper shell (also known as a truck topper, truck cap, or bed cap) is a rigid canopy that covers the truck's bed. It can be made of aluminum or fiberglass.

The top or roof of a camper shell can be level with the roof of the truck or even higher. Some models even have windows on their sides.

The original purpose of a camper shell is to turn the truck's bed into a sleeping area during camping. This purpose converts a pickup truck into a small RV or recreational vehicle.

As time went by, the purpose of the camper shell slowly shifted towards securing cargo and protecting it from the elements and thieves.

If you plan to use your pickup truck the same way, installing tailgate seals will help secure the living area or your cargo in the back of the truck from the elements and thieves.

Tonneau Cover

A GMC Sanoma Truck at the 3rd annual HCS car show at the Hampton Christian School in Hampton Virginia

A tonneau cover is another example of a cover for the truck's bed. However, unlike the camper shell, a tonneau cover is almost flush with the height of the truck bed's walls.

The word tonneau refers to the back of an open truck on top, which is the bed. The word originated from the French word of the same form: "a cask."

A tonneau cover can be rigid or soft, spanning the back of the pickup truck.

Truck owners install a tonneau cover to protect the cargo on the bed of the truck from the elements. A tailgate seal will help improve this protection.

Another reason truck owners install a tonneau cover is to improve the aerodynamics of their trucks.

When the truck travels without any cargo, the wind coming from the front will travel along the front and top shell until it reaches the bed.

The wind inside the open truck bed will push against the tailgate and add resistance to the forward movement of the truck.

Unfortunately, the additional resistance will cause the engine to work harder, consuming more fuel than usual. This affects the fuel economy of the truck.

Thus, covering the truck's bed with a tonneau cover helps improve the truck's fuel economy by eliminating drag from the truck's bed.

How Do You Install A Tailgate Seal?

White Truck Bed, empty bad of an modern white truck, daylight, How To Install Tailgate Seal [Step By Step Guide]

Here are the complete steps to install a tailgate seal on your truck.

It is essential to make sure that the tailgate seal you plan to purchase is created especially for the model of truck that you have.

Using a tailgate seal made for your truck will give you a better seal than one that is not. If no tailgate seal is made for your truck model, pick one with a universal fitting.

Additionally, tailgate seals specify truck models that their product should not be used on.

This can be fitment issues or the gaps between the tailgate and the truck bed that are too small or too large for the sealing product to work correctly.

Always read the product label thoroughly before purchasing your tailgate seal.

It may sound like a simple product to grab, but getting the right seal will give you more value for your money and less headache in the future.

Additionally, check the label for special installation instructions. Some tailgate seals must be installed within a specific temperature range.

Cleaning The Surface Of Your Truck Bed

  1. Clean the edge of the truck bed with your regular car shampoo or an all-surface cleaner. Rinse thoroughly.
    • Focus cleaning on the outer edges of the bed where the tailgate meets the truck bed.
    • Cleaning the edge of the truck bed helps eliminate any dirt affecting how well the seal will stay on your truck's bed. The seal will be kept in place with double-sided tape only.
  1. Dry the area naturally, or tap it dry with a clean rag.
  2. Spray a degreaser on the outer edge of your truck's bed. This will eliminate any grime and grease that the wash cannot remove.
  3. Wait until the surface is dry before you proceed.

This All Surface Cleaner is available on Amazon.

See this Degreaser on Amazon here.

Making Measurements

Pickup Truck Bed

  1. Cut a seal that is half an inch to one inch long.
  2. Position the piece of seal on the perpendicular edge of the truck bed. This is the surface that faces the tailgate when the tailgate is open. Check the area for any uneven surfaces.
  3. Tailgate seals have a rounded tip (some models even have two round tips on both ends) that creates the seal. The round area should point upward at the bottom and inward at the walls. The tip of the rounded end of the bottom seal should be flush with the floor of your truck bed. Position the seal piece so that the rounded tip is flush with the truck bed floor.
  4. Check the adhesive part of the seal piece and ensure it will be on an even surface after you position the rounded end of the seal.
    • This will allow you to identify if you need an additional adhesive. If the adhesive part of your seal will be on an uneven surface, use extra adhesive to attach a bigger area of the seal to the surface of your truck's bed.
  1. Position the seal piece along the vertical walls of the truck bed. Check for uneven surfaces. This will allow you to plan the area where you will install the seals along the truck bed walls.
  2. Measure the length of the surface perpendicular to your truck's bed. Add an inch beyond each side of the bed's walls.
  3. Measure the height of the bed's walls from the top of the bottom seal to the tip where the tailgate meets the wall of the truck's bed.
  4. Cut the lengths of the seal to match the measurements that you made.

3M Double Sided Tape is available on Amazon.

Installing The Tailgate Seals

Rubber Insulation for car glass doors isolated on white background

This next set of steps is best done at night or inside your garage, where you can turn off all the lights.

  1. Position the bottom seal along the bottom of the truck bed. Make sure that the length is correct.
  2. Pull one side of the adhesive cover.
  3. Install the tailgate seal, starting with the small area with an exposed adhesive. Ensure that the top of the rounded end is flush with the floor of the bed.
  4. Lightly press the seal as you pull the adhesive cover, maintaining the seal's level and the bed's floor.
  5. Remove a small part of the adhesive cover of the wall seal.
  6. Position the wall seal on top of the bottom seal.
  7. Lightly attach the seal along the wall.
  8. Do the same for the seal on the side of the truck bed's wall.
  9. Close the tailgate.

Testing The Seal

  1. Turn off the lights.
  2. Have someone move a flashlight along the perimeter of the tailgate. Position the flashlight close to the edge of the tailgate so that there will be minimal light that will escape.
  3. From inside the truck's bed, check the tailgate edge where the flashlight is passing.
    • If you don't see any light leaking through the edges of the tailgate, then the seal is installed correctly.
    • If you see some light leaking, open the tailgate, and check the position of the seal in that area.
  1. Once there are no more light leaks, press the seal firmly against the truck's bed starting from one end. Work slowly along the seal length to ensure that you press the adhesive firmly.
  2. Do the same thing with the seals along the truck bed walls.
  3. Close the tailgate once more and leave it for at least 10 minutes.

To Finish

looking out from the bed of a pickup truck isolated on white

Picking the right tailgate seal that matches the model of your truck is as important as installing it correctly.

Made it to the end? Check out these helpful related articles!

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Tailgate Won't Open? – Here's What To Do!