Copyright 2008 - 2009 by Andrew Mackinnon.  All rights reserved.

• The risks involved in working under a raised vehicle are very great and the stakes are very high.  If caution and common sense are not exercised, there exists the very real possibility of being crushed by the vehicle, resulting in death or, at the very least, serious injury.  There is no margin for error in this matter, which is why I personally adhere religiously to each and every precaution relating to working under a raised vehicle, listed below.  Because I heed these warnings like my life depends on them (and it does), I prepare my vehicle with caution so that I can work under it with confidence that I have addressed all of the risks involved.  I check my vehicle three times before getting under it out of nervousness and will continue this practice always.  The risk of death or horrendous injury is too serious to ignore.
  
  I cannot recommend the following precautions highly enough, that relate to working under a raised vehicle:
  
  
  • NEVER get under a vehicle which is only supported by a jack, even if you think that it might save you some time.  It is not worth the high risk involved.  The vehicle could slip off the jack or the jack could fail and the vehicle could fall on top of you, crushing you and probably causing an extremely painful death or very serious injury at the bare minimum.  Even if the vehicle doesn’t kill the person on whom it falls, it will very likely keep them pinned to the ground until somebody else comes along and lifts the vehicle off them with a jack.  It is unlikely that the person trapped under the vehicle will be able to free him or herself.  This kind of nightmarish scenario is to be avoided at all costs.
  
  
  • Never jack up a vehicle on ground that is not level in order to get under it to work on it.  The risk of the vehicle sliding off the axle stands that you later put under the vehicle to support it is too significant to ignore.
  
  
  • Whenever you need to get under a vehicle to work on it, jack the vehicle up on a level, hard surface (such as concrete or thick, strong pavers) and support the vehicle with high-quality axle stands at appropriate structural points under the vehicle.  After lowering the vehicle onto the axle stands with the jack, the jack should be left holding the vehicle up as a safety back-up.  Any wheels that are still in contact with the ground need to be chocked to stop them from rotating, as outlined below.  If you are at all uncertain as to whether it is safe to get under the vehicle, do NOT get under the vehicle.  It is not worth the risk.  If the vehicle were to fall on top of you, you could easily die or suffer horrendous, life-changing injuries.  Seek out the advice of somebody with more experience if necessary.
  
  
  • It is critically important that the axle stands that you obtain in order to prop up the vehicle and get under it are high-quality axle stands that are rated to carry an appropriate weight in relation to the weight of your vehicle.  Axle stands are generally sold in pairs and should be used in pairs.  (The rating of axle stands for safe working load generally applies to the axle stands being used in a pair.) For raising the front of the vehicle, one pair can be used at the jacking points behind the front wheels on the chassis rails while the rear wheels remain chocked on the ground.  The rear of the vehicle can be raised in a similar manner.
    
    You can find out the weight of your vehicle by looking on one of the plates on the firewall of the vehicle (ie. the vertical panel between the engine bay and the vehicle cabin).  These plates show various details about the vehicle.  For example, my vehicle is 1130 kg in weight.  If I am raising the front of the vehicle only, I am probably raising about 400-600 kg, seeing as more weight is at the front because of the engine (and transmission in the case of front-wheel drive vehicles).  Because my life depends on the axle stands holding the front of the vehicle up when I get under it, it is important that I use axle stands that are rated to safely carry multiple times the weight I am raising.  A pair of high-quality axle stands rated to carry 2000 kg (which is what I use) should be available from your local automotive parts shop.  However it is important to be aware that there are some very poor-quality axle stands being sold as a cheap option in the market place.  The quality of the welds is poor and it is absolutely essential to remember that your life depends on the quality of the axle stands.  If you inspect the axle stands at the shop and find them to be poorly made, do NOT buy them.  If you end up inspecting them at home and find them to be poorly made, do NOT, under ANY circumstances, use them.  Take them back to the shop for a refund and find some high-quality axle stands.  It doesn’t matter if you have to pay even $60 for a pair of high-quality 2000 kg rated axle stands.  Your life depends on them.  Now is not the time to worry too much about saving money.  If you are squashed under a vehicle, you won’t care about the money you saved.  There is no way I am going to entrust my life to some shoddy-looking pair of axle stands and neither should you.
    
    I personally would not use axle stands that are not of a pyramid construction, which is intrinsically strong.  I can recommend an excellent brand and model of axle stand: Workmaster JS2000, distributed by KC Tools International.  Anything with strong pyramid-type construction, high-quality welds and workmanship and compliance with government safety standards is good.  This compliance should be indicated on a label on the axle stand with a statement such as, "Manufactured to Comply with Australian Standards AS/NZS 2538:1995".
  
  
  • Whenever you need to jack up a vehicle, chock the wheels that will remain in contact with the ground with bricks or purpose-built chocks, to prevent these wheels from rotating which could lead to the vehicle slipping off the axle stands that you later put under the vehicle.  This is in addition to other precautions such as using the hand-brake to lock the rear wheels when the rear wheels are in contact with the ground, and putting the transmission into ‘Park’, where the vehicle has an automatic transmission.  It is worth understanding that, in the case of a vehicle with an automatic transmission, putting the transmission in park locks the driven wheels, which may be the front wheels or the rear wheels depending on whether the vehicle is front-wheel-drive or rear-wheel-drive.  (Applying the hand-brake will only stop the rear wheels from moving.) However putting the automatic transmission into ‘Park’ should never be relied upon on its own to lock driven wheels which are in contact with the ground.  Putting the automatic transmission into ‘Park’ should always be accompanied by chocking the wheels which are in contact with the ground and applying the hand-brake as well when it is the rear wheels that are in contact with the ground.
  
  
  • While jacking up a vehicle, keep all parts of your body away from underneath the vehicle in case the vehicle slips off the jack and falls to the ground.  Any parts of your body underneath the vehicle in this scenario will be crushed.  The handle of jack should enable you keep clear of underneath the vehicle while jacking it up.
  
  
  • Whenever working under a raised vehicle supported by axle stands and a jack, it is EXTREMELY important to be aware that the exertion of great force (especially sideways force) to loosen or tighten a bolt or nut could have the effect of the vehicle moving on the axle stands and possibly falling off of the axle stands in some cases, crushing you and causing an extremely painful death or very serious injury.  Whenever working under a raised vehicle supported by axle stands and a jack, it is EXTREMELY important to be aware of the effect that the exertion of great force to loosen or tighten a bolt or nut has on the stability of the raised vehicle.

• If your vehicle’s bonnet is the type that needs a bonnet strut to hold it up, always check that the strut is holding it up securely before leaning into the engine bay underneath the bonnet.  It sounds trivial but if the bonnet falls on you, who knows the extent of the injuries it could cause? The bonnets on some of the older cars are heavy enough that they could quite possibly kill a person if they free-fell.  A lot of vehicles have bonnets that are designed in such a way that there is no way they can fall and they don’t even need a strut to hold them up.

• It is very important to be aware of the risks of explosion associated with motor vehicles.  These risks come from the fuel which is highly flammable and from the hydrogen gas produced by the battery which is also highly flammable.  When working on the vehicle or even simply having the bonnet open, it is very important to eliminate all sources of ignition such as smoking a cigarette near the vehicle, lighting a match near the vehicle or creating an electrical spark near the vehicle.

• When working on the fuel system, disconnect the battery to eliminate the risk of a spark from the electrical system (eg. caused by accidentally shorting the battery or a circuit with a metal tool) igniting the fuel or fuel vapour.

• NEVER touch any part of the ignition system on a vehicle (eg. spark plug leads) when the vehicle is running to avoid receiving a serious electric shock.  Where the vehicle has electronic ignition (which is generally the case on vehicles with electronic fuel injection as opposed to vehicles with fuel delivery via carburettors), such an electric shock could actually result in death due to the higher voltages involved.

• When working on the electrical system, disconnect the battery to eliminate the risk of electric shock.

• Do NOT remove the cap off of the radiator or the coolant reservoir directly after the vehicle has been driven and the engine and radiator are hot.  As the temperature in the engine and radiator increases, the pressure in the cooling system also increases significantly.  Removing cap from the radiator when the cooling system is hot will see burning, hot coolant and steam immediately erupt from the opening to the radiator and burn you ferociously.  Removing the cap from the coolant reservoir when the cooling system is hot could see the same thing happen.
  
  Before taking the cap off of the radiator or the coolant reservoir, wait at least a couple of hours for the cooling system to cool.  (Leaving the bonnet open will help to speed up this cooling process.) Then, since the cooling system will still be somewhat warm, use a thick rag doubled-over a couple of times in your hand to grip the radiator cap.  It’s a good idea to use gloves as well.  Loosen the cap slowly to relieve any pressure in the radiator.  When you are sure that the pressure in the radiator has been relieved and equalised with the outside air pressure, it is safe to fully remove the radiator cap.
  
  Failure to observe the above warnings will, more than likely, result in serious injury.

• Because of the risk of serious injury from burning hot coolant, the best time to check the coolant level is in the morning when the vehicle has not been driven since the previous day and the cooling system, including the radiator, is cold.

• When undoing a stubborn bolt or nut in a confined space with a spanner or socket-wrench, wear tough pig-skin gloves or similar to protect your hand(s) from being cut open on surrounding components if the bolt or nut suddenly loosens or if your hand(s) slips.  It is much better to spend less than twenty seconds putting on a glove or gloves than have to interrupt your work by spending ten minutes attending to a cut to your hand under this scenario.  Having battered and bruised hands from working on a vehicle is not desirable.  Your hands are precious and worth protecting.

• When draining engine oil, automatic transmission fluid, manual transmission fluid or differential fluid after the vehicle has been running and the fluid is still hot, use chemical-resistant gloves (preferably which extend down past your wrists) on one or both hands to prevent your hand or hands from being scalded or burnt by the hot fluid.

• Before working on your vehicle, apply barrier cream liberally to your hands and wrists.  Barrier cream forms a protective barrier by blocking the pores of your skin to minimise the absorption of harmful chemicals, grease and grime into your hands and to make them easier to clean afterwards.  If you use barrier cream, which is available in economical 500 gram containers from your local pharmacist, you will find that grease and grime on your hands cleans up very easily with normal soap afterwards so that no in-grained stains remain on your hands.  Barrier cream also protects your hands from becoming dry and cracked by blocking their exposure to the hydrocarbon chemicals associated with automotive work that cause this.

• Do not let automotive fluids such as engine oil, coolant, fuel, automatic transmission fluid, manual transmission fluid, differential fluid or brake fluid sit on any part of your skin.  Wash them off with soap and water because, like many chemicals, most of these automotive fluids are carcinogenic (ie. cancer-causing) or otherwise hazardous to your health and best avoided altogether by wearing chemical-resistant gloves which are available from your local hardware store.  You skin is porous and will allow these fluids to leech into your body if you don’t wash them off with soap and water or wear gloves to protect your hands.  It is best to re-apply barrier cream to your hands after washing them with soap and water if you are going to continue working on your vehicle.

Copyright 2008 - 2009 by Andrew Mackinnon.  All rights reserved.