Auto A/C Evaporator Leaks

So, here is the scenario... Your A/C System has stopped working. You've been to two different shops and they can't find the leak. What do you do?

Many times the source of  those pesky, unfound refrigerant leaks is the A/C Evaporator. The location of this component is the reason evaporator leaks are tough to find. The evaporator is housed in the evaporator case/housing and buried inside the passenger compartment, between the dash and the firewall in most modern vehicles. This makes even the most advanced leak detectors nearly useless unless the leak it very large.

The evaporator works as a heat exchanger. As cold refrigerant flows internally through the evaporator, the blower motor forces warm air from the passenger compartment to flow through the evaporator externally. As the air flows through, the evaporator absorbs heat from the air and stores it in the refrigerant to be released into the atmosphere outside the vehicle. Leaks and restrictions are the two failures this component can develop over time.

Some common symptoms of evaporator failure are;

Refrigerant Leaks. There are a few techniques like adding a dye to the system that will leak out with the refrigerant and show up around the condensation tube of the evaporator case

Oily residue on the inside of the windshield. Unlike the oily residue from a leaking heater core, this oily reside is odorless and colorless.

Pressure readings that are high on the High Pressure Side and low on the Low Pressure Side of the system.  This symptom may indicate a restricted evaporator...especially if the symptom continues after the orifice tube or expansion valve has already been replaced.

At Kool Kar Auto Repair we take the time and effort to diagnose your vehicle right. Come to Kool Kar for all of your auto repair needs.


Automotive A/C is a specialty that some general auto repair shops don't seem  to understand. Here, at Kool Kar Auto Repair, we get cars in frequently that have been to a general auto repair shop to get the a/c repaired and the customers problem is not solved.  I am not sure if it's lack of knowledge on how the systems works or lack of training or something else.

One of those vehicles came to our shop the other day. It had been to another shop to have the A/C repaired, but they didn't get the problem repaired.  The vehicle was not blowing air through the vent it was suppose to when directed by the control. An extremely expensive part had been installed only to make maters worse than they were before.  Finally the shop told the customer he could not do any more for  the problem and suggested it be taken to a shop that specializes in air conditioning.

We found the problem right away and corrected it quickly.  The part replaced by the other shop was not the problem and did not need to be replaced.

The point I am trying to make is this... if you take your vehicle to a shop for a specific repair and that repair does not get repaired properly, you should take the vehicle back to that shop and ask them to make the repair properly.  I'm not talking about intermittent electrical or electronic problems that can be difficult to track down and repair. You should never have to pay for the same repair more than once.

I have a few suggestions for you when taking your car in for service.  Explain the problem you are having with your car and ask the technician if he is certified to handle your specific problem.  If he says no, ask if he knows a shop that specializes in this specific problem.  You can save time and money by only allowing technicians that are competent in the area of the car you are experiencing problems with.  For instance if the technician is only certified in brakes, that doesn't make him qualified to repair your air conditioning system. 

Kool Kar Auto Repair is The A/C Authority in Texas. Our Customers Give Us a Thumbs-Up on Quality, Service and Price... Every Time.

About Overcharged A/C Systems

The A/C System in your vehicle is a precision system and overcharging the refrigerant can cause damage... sometimes severe damage. Charging the system with out the proper equipment can lead to overcharging and the Do-It-Yourselfer adding refrigerant at home is the most common cause. Just because the A/C doesn't blow cold out the vents, doesn't necessarily mean the system is low on refrigerant. In fact, an over charged system may have the exact same symptoms as an undercharged system.

When the a/c system is overcharged, the system pressures in both the High Pressure and the Low Pressure sides of the system rise dramatically. The result can range from an a/c system that doesn't cool adequately, and leaks, to severe damage to expensive parts like the compressor. To successfully charge the system refrigerant must be added by weight after measuring the weight of the existing refrigerant in the system. 

Some systems hold only a few ounces of refrigerant, overcharging these systems can play havoc on your cars air conditioner.

Bring your car to Kool Kar Auto Repair and our expert technicians will charge your A/C system properly, after giving it a thorough check out to determine if any problem exist. Save Time...Save Kool Kar Auto Repair.  Call today 817-270-2549

The Evolution of Automotive Air Conditioning

The 1940 Packard was the first automobile in the U.S that was offered with Factory Installed Air Conditioning. By the late 60's more than half of all cars sold in the U.S. came equipped with A/C and today nearly 100% of all vehicles sold in the U.S. have A/C. 

From the beginning, automotive air conditioning has relied on a change of state, of the refrigerant, from a liquid to a gas. As the cold gas refrigerant moves through the the evaporator, located behind the dash, warm air from the passenger compartment is blown over the condenser. The cold refrigerant absorbs the heat and moves it out of the passenger compartment. The heat is then released into the atmosphere at the condenser, located in front of the radiator. The type of refrigerant may change... but the basic principle stays the same. 

The real evolution of the automotive A/C system involves the control systems. Initially electronic pressure switches were used to prevent icing by shutting the compressor off when the pressure on the low side fell below a threshold. This prevented icing and resulted in a more consistent A/C vent temperature. Over time  pressure switches were added to the high pressure side of the system.

In modern cars and light trucks, a computer monitors the pressures and can turn off the compressor if a problem is found. Computerized dash controls now control the temperature inside the passenger compartment by controlling the vent and temperature functions of the system.

At Kool Kar Auto Repair, we work hard to stay on top of the evolution of your vehicles air conditioning system. You can count on us to service the system according to the manufacturers specifications. Our Customers give us a thumbs up on quality, service, and price...every time.