Tool Q&A: Using the right chemicals, cleaners and lubricants

Dave Cappert discusses the importance of using the right chemicals, cleaners and lubricants.


This month, we answer questions related to chemicals, cleaners, lubricants and additives. These products—and the right knowledge for using them—can be a real plus in fighting everyday battles in the shop. Since knowledge is power, follow along to stay in front of the challenges that lie ahead.

 Q. We repeatedly get complaints from customers about a musty smell from the A/C vents in their cars. There doesn't seem to be any rhyme or reason to it and the A/C cools just fine. What's up?

A. Vehicles exhibiting this condition have mold growing way down in the deep, dark abyss of the A/C ducts. The problem begins when debris of an organic origin (leaves, bugs, etc.) accumulates and becomes food for mold spores. Moisture and engine heat nurture the mold until it's finally noticed by the sense of smell. Although the problem can occur at any time, it's usually noticed when the A/C is first turned on in the spring. For those with allergies, this problem can be a nightmare. About 15% to 35% of vehicles equipped with air conditioning will become infected, depending on climate, even more so in hot, humid climates. Also, vehicles driven for short periods with the A/C on are more susceptible to getting the problem than those driven for longer periods. While some techs flirt with the use of household disinfectants to kill the mold, the real answer is a special chemical solution from your supplier made for this purpose. You apply it with a special gun to reach into the deep recesses of the air conditioning ducts. Spraying the evaporator core is especially crucial. Allow the solution to soak for a short while and then flush it away with ordinary tap water. This process kills the mold at its source. There are even ultrasonic tools now available for this type of cleaning. Although the frequency of application is based on an as-needed basis, some shops offer the service as part of an annual, air conditioning service package. Although you can't entirely prevent the problem from recurring, you can take a couple of preventive measures to help your customers. First, ensure that the evaporator drain is flowing freely to drain off water and ensure the cabin filter gets changed regularly. Some companies also offer mold inhibitors to deter growth.

Q. When specifying fluids for vehicles, we use owner's manual information or service information stating the recommendation of the manufacturer. Is there any other source we should be aware of?

A. As vehicle and fluid technologies change, fluid requirements and specifications may also change. A new fluid specification may supersede an old one, replacing what was originally required. For the latest recommendations on fluids, make sure to check technical service bulletins as they often contain updated fluid specification information. Don't take this lightly; this may be required to protect an owner's vehicle warranty.

Q. Manufacturers are all over the place with their coolant specifications. Some aftermarket coolants claim universal coverage for all vehicles and that would sure make things easier. Is a universal coolant too good to be true?

A. Without question, it's a literal "alphabet soup" of coolants available today for all the different manufacturers. Rather than making this a debate about selection, perhaps the best answer to coolant selection lies in what's at stake for the owner's vehicle. Manufacturers spend a good deal of money proving out their coolants with their engines and specify a certain type for warranty coverage. To best protect that coverage, follow the manufacturer's recommendation to the letter to ensure warranty protection. Again, this isn't to say that universal coolants are a bad choice; they're just not the factory fill from the car maker. Like any fluid, make sure to check service bulletins to make sure there isn't a revised coolant spec from the original.

Q. When selecting a cleaner for a given application, is there a general rule of thumb to help ensure the right choice?

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