How to Replace a Windshield
Does your car have a cracked windshield that is interfering with your ability to drive safely? Or has a recent wind storm caused a branch to shatter your windshield? If professional windshield replacement seems too expensive or you just like doing your own repairs, it is possible to replace a car windshield yourself. However, if you do not already have the necessary tools (or have someone you can borrow them from), you may not save much money in the end. But if DIY is your motto, then the following information will help you successfully perform a windshield replacement.
Tools and Materials Needed
You will need the following tools and materials ready to go before you begin the windshield replacement:
- Windshield (new or used – just be sure it is free of any scratches or chips and that it is the right size for your vehicle)
- Cold Knife / Windshield Removal Tool
- Electric Knife (in case the Windshield Removal Tool is not sufficient)
- Razor Blade Scraper
- Suction Cup Window Holders
- Scuffing Pad
- Urethane Application Gun
- Urethane Scraper
- Trim or Molding (if you cannot remove the old trim or molding without damaging it, you will need new trim/molding that fits your car)
- Glass Cleaner
- Sturdy Protective Gloves
Note: You may also need a specialized tool to remove the trim around your windshield. Ask your mechanic or someone you trust at your local auto parts store whether there is a special tool for your particular car, and proceed accordingly.
Steps to Remove a Windshield
Before you can replace your windshield, you have to remove it. Remember that you are working with damaged glass, so work carefully and slowly. If your windshield is shattered, not all of these steps will apply. Adjust the following steps, as needed, to fit your car and windshield situation:
- Remove the rearview mirror and any stickers attached to the windshield.
- Remove any trim or molding surrounding the outside edge of the windshield. Do so carefully so as not to damage the trim. (This is the step where you may need a special trim removal tool.) If the molding is simply stuck on, you may be able to pull it away by hand.
- Unless you remove the trim or molding without damaging any of it, you will likely have to get new trim or molding to finish off your windshield replacement.
- Cut around the windshield. With a windshield removal tool, cut around the windshield. You do not have to cut exactly along the edge, but you do need to cut through the urethane bead. Be careful not to nick the exterior paint of the car. Patience is key.
- From inside your car, gently press out along the edges of the windshield. Move slowly around until you know the entire windshield is free and is no longer sticking at any points.
- If a part is particularly stuck, you may not have cut all the way through the urethane. Use the removal tool and carefully cut around the edge from the inside. An electric knife might be easier to use, but it is more likely to damage the car unless you are extremely cautious.
- Remove the windshield. When the entire windshield is free, use the suction cup handles to slowly lift it out and away from the car.
- If your windshield was shattered, you will need to first vacuum up the tiny pieces that have broken off. Then, remove any larger pieces, being careful not to cut yourself. There may still be pieces around the edge of the opening that you will need to cut out with a removal tool.
- Scuff the inside edge of the windshield opening. Use a scuff pad to scrape the inside edge where the new windshield will stick to the reapplied urethane.
- If you will be installing a used windshield, scrape off all but a thin layer of the old urethane. This thin layer will help the new urethane stick better. Then, scuff up the inside edge like you would for a new windshield.
- Remove all but a thin layer of the urethane. Use a urethane scraper to remove most of the urethane bead that still remains on the car. Leaving a thin layer will help the new urethane adhere better.
Steps to Replace a Windshield
Now that you have removed your old, damaged windshield, it is time to replace it with a new (or undamaged used) one.
- Check the paint around the windshield opening. If you see any scratches that reveal bare metal, you need to apply primer paint. Otherwise, the metal may rust, which could potentially affect the security of the windshield. Be sure to choose a primer that works with the urethane you will be using.
- Apply a continuous line of urethane around the edge of the windshield opening. First, cut the tip of the urethane tube. The hole should be triangular shaped. Insert the tube into the urethane gun. Then, using your urethane gun, squeeze out a continuous line of urethane all the way around the edge where the new windshield will lay. When you have made it all the way around, overlap the ends of the bead (line). Check for any gaps in the line, and fix as needed.
- Check your tube of urethane to determine how much time you have to work with it. Some types only allow you 15 minutes from applying the bead to adding the windshield. So, work carefully but not too slowly.
- Place the new windshield into its proper position on the car. Use the suction cup handles to carefully lower the new windshield directly onto the right location. You will not be able to slide the windshield around, so be sure to place it in the correct position the first time. Do your best to leave a small gap all the way around the windshield between the glass and the windshield recess. (This will ensure there is room to cut around the windshield if it ever needs to be replaced.)
- If necessary, use thin pieces of cardboard or wood as spacers to stop the windshield from sliding down.
- Secure the windshield. When the windshield is placed correctly, use medium pressure to tamp it down all around the edge.
- Replace the trim. If the trim or molding you previously removed is undamaged, reinsert it how it was before. Otherwise, you will need to use new trim or molding that fits your particular car.
- Wait for the urethane to set. Urethane gets stronger over time, but the curing time varies depending on type. Some urethane may be safely set within an hour, while other types may require up to 24 hours. Follow the instructions on the type of urethane you are using.
- While you are waiting for the urethane to set, it is advisable to crack a window open before you close any doors. Otherwise, the rise in air pressure may pop out the not yet fully secured windshield. Also, be sure to close the doors gently, even with a window cracked open.
While a professional can usually perform a windshield replacement in 30 minutes, you should set aside several hours to complete the task. Replacing a windshield requires patience and attention to detail, so it is important to not feel rushed. You will also need to account for the curing time that your urethane requires. So, remember that you may not be able to drive your car for 24 hours after you have completed the windshield replacement, and plan accordingly.