How to Repair a Plastic Bumper Dent

A stack of three plastic vehicle bumpers.
  • 2-8 hours
  • Intermediate
  • 100-250
What You'll Need
Tape measure
Car shampoo
Hot air gun or hairdryer
Heat-resistant gloves, clothes, and glasses
Bumper plunger
Petroleum jelly
Power drill
Bumper repair kit
Putty knife
Automotive paint

Anything from a car accident to just backing into a pole can leave a dent in your plastic bumper. An auto body shop can fix it, but why spend hundreds when you can easily do it yourself? By following the steps below, you can remove and repair unsightly dents in your plastic fender, and get your car looking as good as new again.

Step 1 - Inspect

Prior to undertaking any of the work necessary to repair the bumper dent, you should inspect it to determine the severity of the problem. Measure the perimeter of the dent and keep the information on hand. The size of the problem may determine what method must be used to rectify it.

Step 2 - Clean

bumper removed from a car

Clean the area around the dent so any tools you might need to use can work properly. For light debris, rinsing the surface with water should be sufficient; car shampoo should be used for heavier soiling. In either case, use a cloth to thoroughly dry the surface after it has been cleaned.

Step 3 - Use Heat for Small Dents

When you have access to the area behind the bumper and the dent is a minor one, you will find it can be fixed with the use of a heat gun or hair dryer. Heat guns can reach very high temperatures, so be sure you are wearing heat-resistant gloves, clothes, and eyewear when performing this repair. Direct the hot air from the hair dryer or heat gun at the dented section until it is just warm enough to become pliable. Then, simply reach around to push the dent out from the rear carefully. Leave the area to cool when it is finally back to normal.

Step 4 - Rent Tools for Larger Damage

Tools specifically made to repair this kind of damage are available from car accessory supply stores or can often be rented when needed. For larger dents, a plunger tool will be required. The mouth of the plunger must be firmly attached to the surface to create an airtight seal, which can be improved by applying a little petroleum jelly to the rim. Once the plunger is correctly positioned, it should be held tightly and tugged backward to pull the dent out.

Another type of plunger available on the market will require a hole to be drilled into the center of the dent. This will enable a hooked wire to be inserted to pull the plastic back into place. When you need to use this tool, carefully drill the hole so you only create a recess in the bumper and do not go further than necessary.

Step 5 - Repair Cracks or Holes

back of a car

If you noticed any cracks during repair, or if you had to drill a hole to fix the dent, you can use a bumper repair kit to seal it. The kit should contain all the items that you need, but before you buy one, make sure you can use it on whichever type of plastic your bumper is made from.

Mix the repair compound in accordance with the instructions and apply it to the crack or hole with a putty knife until it is filled completely. Even out the surface and use some sandpaper to smooth it once it is dry.

Step 6 - Touch Up Paint

Finish up by going over the whole repair with a proper primer and an automotive paint that matches your specific color. If you're not confident you can match it, this final step may be a job you do have to leave to the pros. Make sure you take care of this as soon as possible, however, because rust can quickly take over areas without a protective finish.