Automotive Glass Replacement - How to Replace Car Glass


Automotive window replacement can be done by the novice if he or she takes their time and has some instruction. It doesn't require any special knowledge or expensive tools to replace car glass, but it does take patience! Here we will talk about replacing a fixed car glass that is bonded to the car body instead of being set into a removable frame.

If you are going to replace car glass that is not set in a frame, then you will basically have to "cut" the old glass out of the car. This procedure requires a few inexpensive tools that are often not in a common tool collection. You need a piece of piano wire to use as a saw, and a couple of inexpensive suction cup handles to lift out the old glass (if it is still in one piece) and to place the new glass into position without touching the edges of the glass.

The first step is to remove any molding that goes around the window. Molding can be attached in several different ways. It may be attached with some sort of clips, glued on, or may be just pushed onto a lip on the car body. This is one place where factory service information comes in handy! Some glass is flush-mounted with the exterior surface of the body and does not have any molding to remove. You also may need to remove one or more trim panels inside the car. Before starting to cut out the broken car window, apply tape to the car body all the way around the window to protect the paint. Next, use an awl to create a hole through the adhesive between the glass and the body. Then push a piece of piano wire through the hole, grab a helper to work the other end of the wire, and use a sawing motion to cut the adhesive all the way around the window. Once you have completely sawn all the way around the broken car window, use the suction cup handles to pull the glass out of the car body.

That was the easy part! The next step is to remove all the old adhesive from the car body, which isn't difficult but it can be tedious! Some service manuals instruct you to leave a thin layer of the original adhesive on the car and just smooth it out, but if it is an older vehicle that may not be the best choice. Once you have removed all the old adhesive (or smoothed it out), you will need to clean the surfaces thoroughly using rubbing alcohol or the cleaner specified by the instructions that came with the new adhesive. Then you will need to prepare both the new glass surface and the surface that the new adhesive contacts. Again, follow the instructions for the type of new adhesive you are using. There may be a primer that needs to be applied to the old adhesive, and sometimes a different primer that goes on the glass. Pay attention to any curing times that are specified. Be careful not to touch any of the contact surfaces with your hands, or you could prevent the adhesive from sealing and bonding properly. After prepping both surfaces, apply a bead of adhesive around the edge of the glass as instructed by the service manual and/or the adhesive instructions. You may be instructed to make the bead slightly larger in the corner areas.

After the new adhesive has been applied and any recommended curing times have been observed, use the suction cup handles to install the new glass into position. Evenly press the glass into the adhesive until it is fully seated all the way around. Do not disturb the vehicle for several hours according to the adhesive instructions, and then be careful not to slam the doors and or drive on any excessively rough roads for several days until the adhesive has had time to fully bond with both surfaces.

That covers the general procedure for auto glass installation. Automotive window replacement can certainly be done by a driver that doesn't have any experience or training in this area, but some jobs are definitely easier than others! If this procedure doesn't sound like something you want to tackle yourself, there certainly isn't any shame in taking your car to an auto glass shop for a replacement, and most shops will even come to your home or workplace to do it for you.