Its important to note that the automobile windshield chip repair exterior trim and moldings that we can see on the outside of the glass are for looks only. The actual water seal comes from the "urethane" adhesive which is used to create the bond. Its in this urethane that the water leak is originating.
Not wearing disposable rubber gloves when handling auto glass Oils and dirt from the installers' hands can contaminate the bonding service of the windshield.
The main question when you are seeking to fix a cracked windshield is whether to replace or repair the glass. Most auto glass shops will opt to repair a crack or chip, as long as it is not directly in front of the driver. They will use a clear resin that is dropped onto the crack and then fixed with an ultra-violet light. The clear resin will then cure and the crack will no longer be visible to the human eye. Most cracks or chips can be effectively fixed in this manner. This method can fix small cracks as well as larger spiderweb style cracks. If an actual hole is formed in the windshield or the crack has traveled too far, your best bet is windshield replacement.
Now you have 3 options. You can pay out of pocket, you can have your insurance company cover the cost, or you can do the repair yourself. The cost out of pocket will vary from $30-$60, depending on the company you chose. Filing with insurance is easy because it is no cost to you, and the auto glass repair company deals with the paperwork. You can also attempt the repair yourself, but if you do not feel comfortable, i would suggest calling a professional. There is a good step by step windshield repair Instructable available, as well as other information online.
If the crack looks exactly the same when completed, it's very likely the technician didn't inject the resin properly. A properly completed repair with cause each area of the damage to disappear from at least from one angle of vision (ex: looking from one side, looking from below, looking from above, etc.).
Not all chips and cracks can be repaired when windshield damage occurs. It is definitely worth the time to have any damage evaluated by a professional to avoid further cracking and damage and eventual replacement.