See Figures 46, 47, 48 and 49
A vehicle must be raised in order to lubricate the chassis, change the oil and gain access to various parts under the vehicle. Above all, a vehicle must be raised and supported safely. Never attempt to work under a vehicle supported only by a jack.
The jack that comes with the vehicle is suitable for raising the vehicle, but is not suitable for supporting the vehicle while you work under it. Once the vehicle is raised, place safety stands under it before attempting any work.
Scissors jacks are the least expensive types of jacks. These are mechanically operated by a threaded rod that is turned inside a diamond-shaped frame. Cranking the screw causes the diamond-shaped frame to expand or contract, raising or lowering the vehicle.
Hydraulic jacks are the best and quickest means of lifting a vehicle off the ground. Hydraulic jacks run anywhere from $30–$300, depending on the size and quality of the jack. They are available as small units that can be picked up easily in one hand and placed where needed, or as large, heavy units equipped with wheels to move them about. The smaller models work slowly and tip over easier.
Hydraulic jacks use a pump to push hydraulic fluid against a ram that operates the lifting pad. They have seals that are prone to leaking. This is one good reason why you shouldn't work under a vehicle supported by a hydraulic jack. If the seals leak, the jack will lose pressure and the vehicle will slowly (or quickly) fall to the ground.
Jackstands are the safest way to support a vehicle. They are made of heavy metal, and are adjustable for different working levels. Once you have raised the vehicle to a convenient height, the Jackstands are adjusted underneath it and the vehicle is lowered onto the stands. Professional Jackstands are the easiest to use, but cost the most. Occasionally, if you're very fortunate, they can be picked up used from a service station that is going out of business.
Drive-on ramps are the alternative to jacking and supporting the vehicle. A good set of pressed steel ramps can cost as much as $40–$70, but they are often worth the expense. Be sure to check the angle of the incline on the ramps. With extensive use of front spoilers and air dams on today's vehicles, often there may be clearance problems.
Fig. 46 A hydraulic floor jack and a set of jackstands are essential for lifting and supporting the vehicle
Fig. 47 Car ramps may substitute for a jack and jackstands, however, old style ramps don't provide adequate clearance for late-model vehicles...
Fig. 48 ...new style ramps have angle adapters to allow clearance for front spoilers on many of today's vehicles.
Fig. 49 When using ramps or jackstands, always block the wheels on the opposite end of the vehicle
See Figures 50 and 51
When you plan your shop supplies, you should follow the same format as you used for your tools- if you intend to perform only basic level work, you need only acquire a minimum number of supplies, and so forth.
At the basic level, you're going to need mostly replacement fluids. Things such as motor oil, antifreeze, automatic transmission fluid and brake fluid should be kept on hand. You'll also need some clean rags or wiping towels and some hand cleaner.
At the average level, things get a little more complex. You'll probably need chassis and wheel bearing grease, spare hoses and belts, plugs, penetrating oil, parts cleaner and a variety of other supplies.
The list of supplies needed for the advanced level could be endless, but if you're operating at the advanced level, you probably already have most supplies. Look at the list prepared here, keeping in mind that it's only a partial list, and these are all just suggestions. Remember the advanced level includes all the other levels as well.
Fig. 50 Hand cleaners have gone high-tech! Lotion, cream, and even citrus. Make sure you have some on hand.
Fig. 51 Shop sealants and adhesives come in a variety of applications. Always read the package before use.
See Figures 52, 53, and 54
If you're not already familiar with the terms "aerobic," "anaerobic" and "RTV", you probably should be. These are the kinds of sealant that have replaced many cork and rubber gaskets on vehicle assemblies.
The terms refer to the curing properties of the sealant. Aerobic means that the sealant cures in the presence of air and can be used on flexible flanges and between machined parts. However, it should not be used where it might squeeze out and plug small passages. Parts must be assembled immediately or the sealant will harden.
RTV sealant is another name for a type of aerobic sealant, standing for Room Temperature Vulcanizing. Aerobic sealants are often identified as RTV silicone rubber compounds, under names such as GM, GE, Permatex®, Devcon®, Dow Corning, MOPAR®, FelPro®, Loctite®, or Versa Chem®.
Anaerobic sealants are those that cure in the absence of air. In other words, the sealant will not cure (harden) until the parts are assembled and the air is denied. Anaerobic sealants are for use between smooth, machined surfaces, but should not be used between flexible mounting flanges. They should also be applied sparingly in a continuous bead to a clean surface.
Uncured aerobic or RTV sealants can be wiped off with a rag. Cured sealants can be removed with a scraper, wire brush or common shop solvents. Fig. 52 Anaerobic sealant is available in several types from a variety of manufacturers
Fig. 53 Epoxy systems are available for metal and plastics and have different drying times
Fig. 54 RTV comes in various colors indicating specific applications. Once again read the package.
Universal Thread Sealant
There are more thread sealants than can be counted. Add to these the several sealant tapes now on the market and the confusion can be great. Mechanics should be aware of the anaerobic sealant with Teflon® filler that can be used on all joints. (GM Truck has adopted it as universal sealant.) "Pipe Sealant with Teflon" is applied to threads. It creates an instant seal, but does not cure for 24 hours. This permits making changes if needed. Once hardened it prevents vibration-induced loosening.
How to Use Sealants
Anaerobics: Clean surfaces with solvent and apply bead to one surface. Material will not begin to cure until parts are assembled. Sealing is effective in half an hour. Full cure is complete in 2½–10 hours depending upon temperature. Cold slows cure.
Aerobic or Silicone sealants: Clean and dry surfaces. Apply bead and let cure for two hours. To make a gasket that will cling to only one surface, apply bead to one surface and allow it to cure. Then apply grease to other surface, and assemble. Or, to make a gasket that will bond to both surfaces, apply and assemble. This will provide maximum blowout resistance. Material will cure to depth of ¼ inch in 24 hours.
When to Use Sealants
The basic guide in choosing a sealant is the size of the gap. Anaerobic materials are used only on smooth, rigid, machine-surfaced flanges which have a total gap less than .030 inch (.301mm). Silicones are used in parts that may flex (such as metal-stamping covers) and which have gaps that are more than .030 inch (.301mm) but not more than 0.25 inch (6.35mm). Both materials are impervious to the normal automotive fluids such as gas, oil, coolants and hydraulics. Anaerobics have a temperature range of - 60–300F (15–149°C), and silicones will handle- 100– 450°F (38–232°C).
Anaerobics: Common applications for the anaerobic materials include fuel pumps, timing covers, oil pumps, water pumps, thermostat housings, oil filter adapters, manual transmission housings, differential covers and other rigid parts. Bear in mind that anaerobic materials add rigidity to the assembly because they help lock the surfaces.
Aerobic or Silicone sealants: Many silicone applications involve stamped metal housings such as oil pans, valve covers, and other parts such as intake manifolds, transmission covers, axle covers and rear main bearing seals.
Solvent release: Non-hardening sealants are used to repair cut gaskets on both rigid and flexible assemblies that operate at high temperatures up to 600°F (315°C). On semi-permanent assemblies, the materials set quickly to bolster the conventional gasket. By remaining pliable, they permit easy removal later.
Hardening sealants dry fast and hard and are used on permanent assemblies to aid the conventional gasket, particularly when the flanges are damaged.
Most sealants also aid in assembly by holding the gasket in place during assembly. When such positioning problems are extremely difficult, a gasket adhesive can be used to hold the gasket in perfect alignment during assembly.
Arranging Your Shop
See Figure 55
Obviously, the arrangement of your shop depends a great deal on just what kind of shop you have in the first place. If you have very limited floor space, careful use of wall space will be the key to allowing yourself working room. If you're like most of us, you probably have a million things in the garage already, which isn't going to help matters. Put up some shelves or get some pegboard to hang tools on. Make sure you have plenty of lighting in the garage. If you don't have enough lights, install some more. There's nothing worse than trying to work by the light of a flashlight or a trouble light. Keep the floor clean and make sure you have adequate ventilation. Keep flammable liquids outside, and anchor all the benches and any heavy equipment you may have. Fig. 55 One vehicle and two vehicle typical shop layout
Servicing Your Vehicle Safely
See Figures 56 and 57
It is virtually impossible to anticipate all of the hazards involved with automotive maintenance and service, but care and common sense will prevent most accidents.
The rules of safety for mechanics range from "don't smoke around gasoline," to "use the proper tool for the job." The trick to avoiding injuries is to develop safe work habits and take every possible precaution.
- Do keep a fire extinguisher and first aid kit handy.
- Do wear safety glasses or goggles when cutting, drilling, grinding or prying, even if you have 20–20 vision. If you wear glasses for the sake of vision, wear safety goggles over your regular glasses.
- Do shield your eyes whenever you work around the battery. Batteries contain sulfuric acid. In case of contact with the eyes or skin, flush the area with water or a mixture of water and baking soda, then seek immediate medical attention.
- Do use safety stands (jackstands) for any undervehicle service. Jacks are for raising vehicles; jackstands are for making sure the vehicle stays raised until you want it to come down. Whenever the vehicle is raised, block the wheels remaining on the ground and set the parking brake.
- Do use adequate ventilation when working with any chemicals or hazardous materials. Like carbon monoxide, the asbestos dust resulting from some brake lining wear can be hazardous in sufficient quantities.
- Do disconnect the negative battery cable when working on the electrical system. The secondary ignition system contains EXTREMELY HIGH VOLTAGE. In some cases it can even exceed 50,000 volts.
- Do follow manufacturer's directions whenever working with potentially hazardous materials. Most chemicals and fluids are poisonous if taken internally.
- Do properly maintain your tools. Loose hammerheads, mushroomed punches and chisels, frayed or poorly grounded electrical cords, excessively worn screwdrivers, spread wrenches (open end), cracked sockets, slipping ratchets, or faulty droplight sockets can cause accidents. Likewise, keep your tools clean; a greasy wrench can slip off a bolt head, ruining the bolt and often harming your knuckles in the process.
- Do use the proper size and type of tool for the job at hand. Do select a wrench or socket that fits the nut or bolt. The wrench or socket should sit straight, not cocked.
- Do, when possible, pull on a wrench handle rather than push on it, and adjust your stance to prevent a fall.
- Do be sure that adjustable wrenches are tightly closed on the nut or bolt and pulled so that the force is on the side of the fixed jaw.
- Do strike squarely with a hammer; avoid glancing blows.
- Do set the parking brake and block the drive wheels if the work requires a running engine.
- Don't run the engine in a garage or anywhere else without proper ventilation- EVER! Carbon monoxide is poisonous; it takes a long time to leave the human body and you can build up a deadly supply of it in your system by simply breathing in a little every day. You may not realize you are slowly poisoning yourself. Always use power vents, windows, fans and/or open the garage door.
- Don't work around moving parts while wearing loose clothing. Short sleeves are much safer than long, loose sleeves. Hard-toed shoes with neoprene soles protect your toes and give a better grip on slippery surfaces. Jewelry such as watches, fancy belt buckles, beads or body adornment of any kind is not safe working around a vehicle. Long hair should be tied back under a hat or cap.
- Don't use pockets for toolboxes. A fall or bump can drive a screwdriver deep into your body. Even a rag hanging from your back pocket can wrap around a spinning shaft or fan.
- Don't smoke when working around gasoline, cleaning solvent or other flammable material.
- Don't smoke when working around the battery. When the battery is being charged, it gives off explosive hydrogen gas.
- Don't use gasoline to wash your hands; there are excellent soaps available. Gasoline contains dangerous additives which can enter the body through a cut or through your pores. Gasoline also removes all the natural oils from the skin so that bone dry hands will suck up oil and grease.
- Don't service the air conditioning system unless you are equipped with the necessary tools and training. When liquid or compressed gas refrigerant is released to atmospheric pressure it will absorb heat from whatever it contacts. This will chill or freeze anything it touches. Although refrigerant is normally non-toxic, R-12 becomes a deadly poisonous gas in the presence of an open flame. One good whiff of the vapors from burning refrigerant can be fatal.
- Don't use screwdrivers for anything other than driving screws! A screwdriver used as an prying tool can snap when you least expect it, causing injuries. At the very least, you'll ruin a good screwdriver.
- Don't use a bumper or emergency jack (that little ratchet, scissors, or pantograph jack supplied with the vehicle) for anything other than changing a flat! These jacks are only intended for emergency use out on the road; they are NOT designed as a maintenance tool. If you are serious about maintaining your vehicle yourself, invest in a hydraulic floor jack of at least a 112 ton capacity, and at least two sturdy jackstands.
Fig. 56 Always support your vehicle on jackstand while working underneath
Fig. 57 If you're using portable electric tools, make sure they're grounded, preferably at the plug by a three wire connector
THIRD WIRE GROUNDING THE CASE THREE-WIRE CONDUCTOR
GROUNDING THRU A CIRCUIT
ONE WIRE TO A GROUND THREE-WIRE CONDUCTOR
GROUNDING THROUGH AN ADAPTOR PLUG