As all vehicles need maintenance at some point, many owners will make repairs themselves.  There are certainly varying degrees of home maintenance, from an oil change to an engine overhaul.  While it saves the car owner a lot of money, it is important that you work safely.

- First and foremost, do not attempt repairs that are beyond your ability. If you feel unsure about a repair, you should seek out a competent professional to do the work for you. Better to pay someone who knows what they’re doing than to attempt to fix it yourself and screw it up. Many systems today are complex and involve computers; repairs often require special tools and equipment.
-  It is also important to know your physical limits. Don’t attempt repairs yourself if you’re not physically able to do the work.  Auto repair often requires heavy lifting and positioning in awkward positions, so use common sense and do not hurt yourself. 
-When you make the repair, make sure you are alert and unimpaired by medication, alcohol, or even fatigue. 
-Never smoke while working as you may be dealing with fuel. 
-Before going under a vehicle, make sure it is secure, always block the wheels.  If you are doing electrical repair work disconnect one of the battery cables.  This will prevent accidental shorts that could damage the wiring or start a fire.
-Wear proper clothing, with nothing loose, such jewelry, neckties, or bulky gloves, even your hair. These items may become entangled in pulleys or moving parts causing serious injury.  Watch out for the drive belts, pulleys, fan and other moving parts when working under the hood if the engine is running.
-Things can get hot if the engine has been running, the engine, radiator, exhaust manifolds, catalytic converter, muffler and pipes could be a burning hazard.
-Never open the radiator cap on a hot engine. Always allow the engine to cool for at least an hour before attempting to open the cap.  When you do, slowly loosen it to release any steam or pressure.
-Do not open up any brake lines or replace any components in a vehicle equipped with an "integral" ABS system (one where the master cylinder is combined with the ABS modulator, pump and pressure accumulator) without first depressurizing the system. This can usually be done by depressing the brake pedal 24 to 40 times while the key is off.
-Use caution when opening any fuel lines on a fuel injected vehicle. The pressure in some systems may be as high as 80 to 90 psi when the engine is running. Residual fuel pressure can remain in the lines for many hours after the engine has been shut off.
-Keep your focus to prevent mistakes.  Avoid distractions such as children, friends, spouses, or pets.
-If possible, let someone know you are working under the vehicle or outside in case of emergency.

These are just some quick tips to remain safe while working on your vehicle.  Just remember, if you are in over your head, you may end up paying more than you would have if a mechanic fixed it in the first place.  And, with safety, be aware that there are dangers and use common sense.