Photo from Car Talk Service Advisor:Coolant www.cartalk.com
What is it? Coolant is the fluid that absorbs heat from the engine and then dissipates it through the radiator. It is also dissipated through the heat exchanger in the passenger compartment when you crank your heat in the winter. Coolant, which is commonly called antifreeze, is a mixture of ethylene or propylene glycol and water, usually in a 50/50 ratio. Servicing the coolant involves draining and/or flushing your car's cooling system and then replacing the old coolant with fresh coolant.
Services Performed: Draining out the coolant and refilling the system removes dirt and rust particles that can clog up the cooling system and cause problems in winter and summer.
How Often?: Every 40,000 kms
How much? $149.00 + cost of coolant
Why do I have to do this? Because it is operating in a hot, hostile environment, coolant will break down over time. Most importantly, the coolant's rust inhibitors get used up, leaving the small cooling passages in your engine and radiator vulnerable to corrosion. Even with these rust inhibitors, some corrosion will inevitably take place, contaminating the coolant with debris. This debris is the reason the fluid needs to be drained and replaced on a regular basis.
What happens if I don't do this? If the rust inhibitors stop working, the cooling system will rust from the inside out. The biggest source of rust in a car's cooling system is the engine block. In time, these bits of rust will also clog the tiny passages within the radiator and heater, causing your engine to overheat. When an engine overheats, the result is a bonus yacht payment to your mechanic that someone else should be making. This AC DELCO head gasket video shows the damage caused by not doing regular coolant flushes. A head gasket may be rebuilt but if not caught soon enough may result in the engine needing to be replaced. This is a $2500.00 to $8000.00 repair.
Regular inspections, another important preventative maintenance service will catch coolant leaks more quickly, preventing unnecessary repairs. There are several components involved with caring for your vehicle's cooling system. Should probably do another unit and connect it to this: something to do with the major systems of a vehicle...
Maintenance Tip: Check your coolant level periodically. Your owner's manual will have a recommended interval in which to check the coolant level. Most cars have a plastic coolant recovery tank connected to the radiator by a hose (see photo), so there's no need to open the radiator cap itself (orange label at bottom). The coolant level should be at the tank's MAX or HOT line when the engine is hot, and lower when it's cold. If you check your coolant level when the engine is cold, the coolant should be at or above the "minimum" or "fill" line on the transparent refill container. If you check your coolant level when the engine is hot, the coolant should be at or just below the "max" line. Disappearance of coolant could be caused by either an external or internal leak, the second being more expensive.Either one should be addressed quickly, since running low or out of coolant can lead to catastrophic engine failure.