Air Conditioning Explained

Heat Wave!

ARE YOU HOT?!  
Air Conditioning Explained

Your car's ‘skin’ of steel and glass is not only protective and beautiful, but it also attracts and stores a tremendous amount of solar (radiant) heat in the passenger compartment.

Removing this trapped heat requires a very efficient system. The Air Conditioning (A/C) system is a combination of mechanical components plus a chemical medium (Freon – not a psychic) whose sole purpose is to move heat from the interior to the exterior of the vehicle.

Your car’s air conditioner uses Freon Refrigerant to cool the air internally. Freon acts a lot like water. As liquid Freon warms up it evaporates into a gaseous state (vapor), and then, as it cools down, becomes liquid again. As the Freon changes from a liquid to a vapor it heats and cools the air.

What path does Freon take? When you dial the temperature in your car to Cold the Freon moves through the Receiver-Drier (see diagram) which collects moisture and dirt.

Air Conditioning System

After the receiver drier, Freon turns into vapor inside the Evaporator where it chills and takes the heat out of the air. The evaporator is located inside the car.

Then the vapor travels back to the A/C Compressor (in the engine area) where it gets compressed. Then the Freon flows to the condenser.

Next the Condenser condenses the Freon back into a liquid state – creating heat under the hood, in the engine compartment. The condenser is located in front of the radiator. As the Freon completes its circuit by traveling back to the Evaporator to become vapor, it chills the air.

As you notice in the visual aide, there is quite an infrastructure of hoses to carry Freon to the various A/C components: there is approximately 24 feet of very fancy hose with special crimpings and fittings.

An air conditioner has super high pressures – up to 500 psi (‘pounds per square inch’). This is about 20 times the air pressure in your tires or 10 times the pressure of water as it comes out of your faucet.

In order to perform properly, your car’s air-conditioner requires that all of the parts be functioning correctly. Working on A/C systems requires (by the B.A.R.) special equipment, training and certification. Water Star Motors, of course, has all of this and more!

A note on Freon: Currently, all new cars have Freon type 134A. (environmentally friendly). Transition to environmentally friendly Freon began in the late 80’s. Older cars have the Freon R-12 (the O-zone Killer).

Water Star Motors is running an air conditioning special.

Brake Fluid System

STOPS CAR!

You depend on your brake system to stop your car effectively – especially in an emergency situation! Today, we will delve deeper into our exploration of THE BRAKE SYSTEM.

The average car’s brake system has at least 40 feet of steel brake lines plus 2-6 feet of reinforced rubber hoses; a reservoir; and a plethora of moving parts, including the brake master cylinder. Mostly made of metal, these parts are susceptible to rust and corrosion. All of these components are filled with or exposed to Hydraulic Fluid – a.k.a. Brake Fluid.

In order to do its work effectively, brake fluid – a vital part of the brake system – must be fresh and clean, uncontaminated by dust, dirt and debris, moisture and/or air bubbles. Contamination has dastardly effects, including reducing the brake fluid's boiling point AND its anti-corrosive properties.

Car engineers confine brake fluid within a sealed system. However, even with that precaution, it still gets old after a year or two, and contamination still happens. (If, for example, the cap was left off the brake fluid reservoir, complete contamination will occur within 24 hours.) Not only does dust and dirt get into it, but consider the hygroscopic nature of brake fluid. Yes, it's true: it actually absorbs moisture out of air. Big trouble!

Imagine how HOT the brakes get while stopping your car. (There is nothing quite like the smell of burning brakes!) Brake fluid is designed to not boil until it reaches 440 degrees; (twice the boiling point of water). Once it is moisture-ridden and/or old, however, it will boil at much lower temperatures. Sadly, when brake fluid boils air enters the sealed system, diminishing the braking ability. You will discover that your car will be especially prone to brake-fade under heavy or emergency stopping conditions. (Remember those "runaway truck ramps" on steep hills?)

What effect does contaminated brake fluid have? Remember the 40 feet of metal through and around which the brake fluid resides? Guess what: it starts to corrode. Debris from corrosion makes the fluid 'dirty', affecting calipers, wheel cylinders, hoses, and expensive anti-lock brake units*.

*(Especially on some newer cars; anti-lock systems, brake assist systems, and electronic stability programs can have extremely expensive components. When damaged by contaminated brake fluid, repairs can cost in excess of $2000. Yikes!) Therefore, brake fluid maintenance, especially with today’s high-tech braking systems, is a very important investment to make for your financial – as well as your physical – well-being.

How do you know if your brake fluid is okay? If it looks brown or black, it is dirty. Clean brake fluid is colorless and clear – but sometimes even contaminated brake fluid still appears colorless. YOU CAN'T TELL BY LOOKING. Bring your car into Water Star Motors. We have a special tool to measure the amount of water in your brake fluid. A finding of 2% moisture or more is considered excessive.

Preventive maintenance is the key to the longevity of your vehicle and its brake system.

Most manufacturers recommend a brake fluid flush every two years. Higher-end cars recommend a flush once a year. A Brake Fluid Flush prevents potential damage to your brake system components, expensive repairs, and possible brake failure by clearing out the water and most of the dirt that builds up over time.

Have you had your Brake Fluid Flushed lately?

Green Car, Happy Car!

Every day people are becoming more attuned to being 'green'. From the Serene, Green Auto Repair Team stand-point there are many pro-active things to do to keep you driving green.

What can I do to make my car be on the Green side of things? One well known thing is to check your tire pressures regularly and make sure they're not lower than factory specs. Some folks say set tires higher than normal. This is OK if you monitor your tire wear, making sure the center of the tire treads are not worn. It is not too green to get merely half the life out of tires because the pressures are set too high. (Do not go more than 2-4psi [pounds per square inch] over factory specifications.)

Maintenance: A properly maintained vehicle gets better fuel mileage and puts out less smog producing fumes than a poorly running car. A clean air filter and fresh spark plugs can make a world of difference in how efficient your engine runs. Changing the oil and filter regularly also affects fuel mileage as well as the life of the engine. Oil, as it ages, thickens and the oil filter gets clogged. Also using the wrong weight oil, (to heavy) will affect fuel mileage.

Bodily Fluids! It is not green to have a car that constantly leaves fluid deposits on an already contaminated planet. Most leaks leave a spot under the car. Other fluids leak primarily when the car is running. In this case there may be a spot when parked, but a large leak while driving down the road. There is no good reason, financial or otherwise, to let a car leak any of its highly toxic fluids on our planet earth. Get those leaks fixed!

On occasion, tightening up the 'loose nut behind the wheel', will help with fuel mileage. In other words, slow down a little. Don't make jack rabbit starts, and accelerate smoothly to cruising speed. 'Drive like there is an egg between your foot and the accelerator pedal.' Smooth controlled stops also help prolong the life of brake pads and rotors.

New car vs. old car? It takes a tremendous amount of energy to produce a new car. One way to recycle is to fix up that old car and give it a new lease on life. (It's better to start with a mid 1990's or newer due to emissions technology. Also, they generally are more reliable.) Cars can be immortal.

To be green is good! Check out Water Star Motors, a certified green Import Auto Repair shop in Santa Cruz. http://www.waterstarmotors.com/

Thanks, The Sage Mechanic