Coolant

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.

Should I do this service when it's recommended?

Most cars have a plastic coolant recovery tank (top of photo) connected to the radiator by a hose, 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.

Yes. 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.

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.

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.

Is there any maintenance required between intervals?

Check your coolant level periodically. Your owner's manual will have a recommended interval in which to check the coolant level.

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 latter being more expensive. 

Drive Belts

What is this?

Tiny cracks in a serpentine belt aren't necessarily bad, but the deep ones here mean it's running out of time. Because this belt was removed to replace an alternator, the mechanic replaced it with a new one to save trouble down the road.

This is the inspection or replacement of the belt(s) in your engine compartment.

Every car has a water pump, a power-steering pump and various accessories — all of which are powered by rubber drive belts. On older cars, each of these components is driven by its own belt. On most modern cars, all of these components are driven by one belt, called a serpentine belt.

Should I do this service when it's recommended?

Definitely.

Why do I have to do this?

Belts in your car don't last forever. They wear out from use and eventually crack and decay from ozone that's in the air.

What happens if I don't do this?

If your car has individual belts and one of them breaks, then you'll lose the function of whatever part that belt was powering, such as the alternator, power-steering pump or water pump. If the serpentine belt breaks, all of these parts will stop functioning. Engine damage may result from overheating.

Brakes

What is it?

Brake pads, linings and rotors are parts of your car's brake system and are housed next to each of the wheels. They push against one another to create friction, which stops the car.

The disc brake caliper (1) squeezes brake pads (2) against either side of the rotor (3). The rotor is part of the hub (4), to which the wheel attaches.

There are two kinds of brake systems: disc brakes and drum brakes. Disc brakes are the most common system in use today, and they're very much like the hand brakes on a bicycle. When you step on your car's brake pedal, the brake pads squeeze a spinning disc rotor that's attached to the wheel. The resulting friction, when applied to each of the wheels, slows the car.

The second type, drum brakes, involve brake shoes that push out against a spinning brake drum, which is attached to the wheel. This friction slows the car.

Both systems work by creating friction, so brake parts are expected to wear out. The questions then are, how worn out are they? And are they worn out enough that they need to be replaced?

That's what this service is all about checking these components for wear and other potential problems.

Should I do this service when it's recommended?

Absolutely.

Why do I have to do this?

In short, you do this service so you don't crash into a cabbage truck.

What happens if I don't do this?

If you neglect your brake pads and shoes, your brakes will ultimately fail. Even before that happens, however, you can cause damage to other, more expensive brake parts, such as rotors, drums and calipers. In other words: a stitch in time ... saves you from helping your mechanic with a boat payment later on.