Connect the manifold gauge set as discussed above. Connect the yellow hose to the can tap valve and windshield repair seat (turn clockwise) the valve. Close the blue gauge on the manifold gauge set. Open the valve on the can tap valve. Slowly open the valve on the blue or "low-side" gauge and let the refrigerant flow from the refrigerant can into the system until you see a reading of 60psi on the "low-side" gauge. TIP: Placing the refrigerant can in a pan of hot water will allow the vapor refrigerant to enter the A/C system quicker. WARNING: Do not invert the refrigerant can. Doing so will allow liquid refrigerant to enter the system resulting in a ruined compressor.
Automobiles are made so that a cracked windshield can be replaced; they are not made to be repaired. To my knowledge, manufacturers do not recommend or promote repairing windshields they recommend replacing them. A windshield is a structural part of the body and is in place for safety reasons. You shouldn't mess with the overall safety of the car by repairing a glass that is vital to safety during a rollover or accident.
Every day people are buying into the dream of owning their own business, with windshield repair being at the top of the list due to the low start-up costs involved. Most will fail.
If your windshield can be repaired then the fix auto glass repair is relatively easy. The entire process usually only takes 30 minutes to an hour depending on the specialist and the shop. With a simple resin that is cured by sunlight, the specialist will inject the epoxy into the chip or crack with a special set of tools. This fills the damage and dries completely clear as it cures.
The bottom line is you don't want to be caught by law enforcement with a cracked windshield. You also don't want to be seen by your friends, riding around in a car with a broken windshield. Not only is the citation costly, you may never be able to live down the embarrassment that you feel every time see you in your car before you have gotten it fixed. Spare yourself the trouble and get that window fixed as soon as possible. You don't want that small blemish to become a bigger blemish that can cause injury to you and your friends.
Professional A/C technicians use an electronic leak detector to find leaks in an system. Use a battery-powered UV leak detector kit and special UV glasses. This kit can be purchased at auto supply stores and Internet A/C supply store fronts.
Sometimes, the crack in the Auto Windshield glass is very long and unavoidable. In such cases, its better to replace the glass instead of repairing it. The reason is that in the long run it will be more harmful than the crack itself. It might break in the car itself when you are driving because of the stress.