Hand tools must be kept in safe condition. The following are some hand tool safety considerations:
• Pounding on chisels will result in the top of the chisel folding over in the shape of a mushroom.
Do not use a mushroomed chisel until it has been reground.
• A file has one pointed end called a tang. To prevent hand injuries, install a handle on the end of a file.
• When loosening a fastener, pull toward you rather than pushing away.
• Do not use a pipe to increase leverage when tightening the handle of a vise. This can break the vise.
Puller Safety Many types of pullers, ranging from small to large, are used in automotive work. Pullers are used
to remove or install pressed-fit gears, bushings, bearings, or other parts from shafts. Specific uses of many of the pullers discussed here are covered in later chapters.
When using pullers:
• Wear eye protection.
• Be sure the pressure screw is clean and lubricated before using an impact wrench.
• Be sure the removable point is installed on the puller.
• Be sure the puller is aligned so it is perpendicular to the part being pulled.
• Do not use a puller with damaged or worn parts.
• Use the correct size puller so overloading is avoided.
• Use a three-jaw puller instead of a two-jaw puller when possible.
• When heating a part to help free it, do not heat the jaws of the puller. This could change the temper of the metal.
Press Safety
There are many special-use press fixtures available. For press work, a bearing separator plate is often used. Be sure to support it where the bolt holds the two halves of the tool together If the separator is installed in the press 90° to the correct position, the bolts will be bent and the tool can be damaged.
Air Tool Safety
Air tools are great time-savers for technicians. In addition to blowguns, there are many air-operated
tools, including air drills, air valve seat grinding motors, air-operated valve spring compressors, and air hydraulic jacks. An air compressor provides air at a regulated pressure of 90 to 150 psi (pounds per square inch). For the best performance and reliability, air tool manufacturers recommend regulating air pressure
to 90 psi to get the longest life from air tools.
Compressed air is very useful to a technician, but it can be dangerous when used improperly. Horseplay has no place in a shop! A blast of air can break an eardrum. Blowing compressed air into an orifice of a .person’s body can result in death. Observe the following safety precautions when using air tools:
• Always wear eye protection when blowing off parts. Pieces of debris can be blown into your eyes. Always blow down and away from yourself.
• Do not blow air against your skin; the highpressure compressed air used in auto repair shops can penetrate skin. Pressurized grease from a chassis grease gun can penetrate skin also. • Hold onto an air hose when uncoupling an air line so it does not fly through the air. When possible, bleed off the air from an air line before uncoupling an air hose. There are two basic types of blowguns . Blowguns designed for blowing off parts are regulated to produce no more than 35 psi. Rubber tipped blowguns, used to blow into fluid passageways or engine oil galleries, do not have this safety feature. A worker should not use these tools
until proper instructions on their safe use are given.
Impact Wrenches. The air impact wrench is a favorite technicians’ tool. A 1⁄2'' drive impact wrench is used to loosen large, very tight bolts. Special, extra thick impact sockets must be used with the impact wrench Regular sockets can crack or explode Follow these precautions when using an impact wrench:
• Be careful of loose clothing or hair that might become tangled in the tool.
• Use approved impact sockets, not chrome sockets.
• Be sure that the socket is secured to the air tool. A clip at the end of the tool’s square drive can become worn so that it no longer holds the tool.
• When the impact wrench fails to loosen a fastener, use a large breaker bar.
• When using a wobble socket, do not turn on the
impact wrench unless it is installed on a nut or bolt. The socket can fly off the impact wrench, possibly causing an injury.
Air Chisel. An air chisel is a miniature jackhammer often used to drive valve guides
in and out of cylinder heads. There are many attachments available for a variety of uses.
When using an air chisel:
• Before pulling the trigger, be sure to have the tool bit against the workpiece. Otherwise the tool might fly out of the gun.
• Be sure to wear eye protection.
Die Grinder. Air-powered die grinders turn at very high speeds, often in excess of 20,000 rpm. Be certain
that an abrasive disk or grinding wheel used with the die grinder is rated at sufficient rpm.
General Machinery Safety
• To the eye, swiftly rotating machinery can at times appear not to be moving. Lights powered by ordinary
alternating current flicker 60 times per second. This can produce a strobe effect on moving machinery. Be cautious when working around a running engine or rotating machinery. Fingers can be severed by a moving belt and pulley.
• Do not talk to someone who is operating a machine; do not talk to someone when you are operating a machine.
Drill Safety
• Always wear eye protection.
• Release pressure occasionally to allow chips to break off before they become too long and dangerous.
• A drill bit may catch when it starts to break through the bottom of the work being drilled. Be sure that sheet metal is clamped to the worktable. Let up the pressure on the bit as it starts to break through the bottom of the hole.
• If the drill grabs the work, shut off the drill. Never grab the moving work.
• Never stand in water when drilling. Standing in water increases the danger of electrical shock.
• Be sure to remove the chuck key from the chuck before drilling. Grinder Safety
• Stand to the side when starting the motor. The grinding wheel is more likely to explode during startup because of the inertia of the wheel.
• Wear face protection.
• Position the tool rest as close to the wheel as possible, so that nothing can get trapped between the wheel and the tool rest
• Do not grind on the side of the grinding wheel.
LIFTING EQUIPMENT
Automotive repair work includes lifting heavy items like engines, transmissions, and entire vehicles. Safe lifting practices will prevent accidents and injuries. Hydraulic Jacks A hydraulic floor jack is used to raise and lower the vehicle and to help position heavier components, such as engines and transmissions.
Position the jack under the vehicle frame, or at one of the correct lift points shown in the service literature Many vehicles are built
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