Every vehicle fluid has a second use, but three of them are hazards: engine coolant (ethylene glycol) is lethal if swallowed and tastes sweet, windscreen washer fluid is often methanol, which can blind and kill and burns with a nearly invisible flame, and used motor oil carries combustion residues and fouls water. Drain each fluid into its own labelled, sealed container, never mix them, and keep all of them away from drinking water, food containers and children.
A vehicle holds litres of oil, coolant, brake fluid, transmission fluid and washer fluid, each made for a hard job and each reusable for another. Their value lies in labelling them right.
Each Fluid Has A Second Life And A Specific Way To Hurt You
Motor oil (parent article uses). Lubricant for any mechanical system, a rust preventative for tools and metal, a wood preservative for fence posts and tool handles, a fire starter when soaked into rags, and lamp fuel that is smoky but works. Used oil contains combustion by-products, so keep it off skin and out of streams and wells.
Coolant (antifreeze, ethylene glycol). Antifreeze for water systems in cold weather, and a heat-transfer fluid for solar thermal systems. It is toxic and lethal if swallowed, and its sweet taste attracts children and animals. Store it securely and label it clearly (parent article).
Brake fluid. Hydraulic fluid for improvised hydraulic systems. It is corrosive to paint and many plastics, so handle it carefully (parent article). Keep it sealed; it absorbs moisture from air.
Transmission fluid. Hydraulic fluid, and lamp fuel that burns cleaner than motor oil. The parent article gives a 50/50 mix with acetone as an excellent penetrating oil; acetone vapour is highly flammable, so mix and use it in the open with no flame around.
Windscreen washer fluid. Often methanol-based, usable as antifreeze, a solvent, or fuel for alcohol stoves. Methanol is poisonous by swallowing, skin contact and breathing the vapour, and it burns with a nearly invisible flame. Washer fluid also contains water and detergent and cleans surfaces as it is (parent article).
What You Need
- Drain pans and clean, sealable containers, metal or fuel-rated plastic, in several sizes.
- Funnels, rags, a marker and labels.
- Sand or absorbent soil for spills.
- Gloves and eye protection.
Method: Drain Cold, Label At Once
Step 1: Let the engine cool before draining; hot oil and coolant scald.
Step 2: Place the pan, loosen the drain plug slowly and let the fluid run until it stops. Radiators drain at a petcock or a lower hose.
Step 3: Pour into a labelled container immediately. Write the fluid name on the container itself, not only on a pile of labels.
Step 4: Do not rely on colour. Colours vary between makes and the same colour can be two different fluids. Label by where it came from.
Step 5: Store sealed, upright, in a shaded spot away from living space and food, and away from fire.
Step 6: Clean up spills with sand or soil, scoop it into a pail and keep it away from water.
Common Mistakes
- Using a drink bottle for coolant or washer fluid. Someone drinks it.
- Mixing fluids “because they are all dark.” Mixed fluids are useless and hard to identify.
- Draining fluids onto the ground. It contaminates soil and water.
- Burning washer fluid or methanol indoors. The vapour poisons and the flame is hard to see.
Safety
Poison, near-invisible flames and flammable solvent
Coolant and washer fluid can kill if swallowed, and methanol can also harm through skin and breathing. Label every container clearly, never use food or drink containers, and keep fluids away from children and animals. Methanol and acetone mixtures burn; use them outdoors with nothing burning nearby, and never pour methanol onto a fire. A methanol flame can be nearly invisible in daylight, so a burning spill may look as if it is out; keep clear until it has been smothered with sand or soil. Wear gloves and eye protection when draining.
What’s Next
- Learn next: Repurposing Engines & Motors — what the oil and coolant were for
- Combine with: Hydraulic Systems — using brake and transmission fluid in hydraulics