MAINTENANCE

Pierre Bissonnette
pierrebissonnettejr@sympatico.ca

6 June 2009

A/C Systems

Time for a Check Up

Spring is in the air and your clients’ vehicles should be getting a good going-over from the consequences of a long, cold winter. A good thing to start with is the A/C system… something that likely wasn’t used during the past few months.

First you need to check the condition of the evaporator. If the customer has complained about the presence of a ‘rotten egg’ smell upon starting his A/C, it would be coming from the evaporator. This could last for about 10 minutes before dispensing because the A/C had not been used during winter months. If the odour persists, there is a leak in the evaporator.

Condenser

A leak detector process is something that is regulated across the country and should be done on the A/C system. The condenser is the A/C’s ‘radiator’ and is found in front of the vehicle’s radiator. In a five-year or older vehicle, it needs to be checked for leaks and the condition of the fins—rocks and stones can easily damage them. If this happens, replacement is needed and is not cheap. In the case of a minivan, there is a rear heater and evaporator, so don’t forget them. They, too, are expensive to replace.

Most systems also have a dryer that should be changed about every five years if the A/C is to work perfectly. The dryer picks up the humidity inside the system and when it gets filled up, the system will not work as efficiently as it should.

Belt and tensioner

Most vehicles use only one serpentine belt with tensioner. This is something that is spring-loaded and will pick up water, snow, salt, etc. from the ground. Eventually after 5-6 years, the tensioner could jam in one position and cause the belt to squeak. When the A/C comes on, the sound will be louder and is certainly caused by the tensioner jam, which needs to be rectified.

Don’t forget to check the R134 coolant. If you are not certified to do this job, get someone who is as this is a regulated procedure and must be done correctly and forms filled out accordingly. The amount of R134 taken out must be documented as well as the amount put in the A/C system. A sticker under the hood will confirm this procedure has been done correctly and legally.

Radiator coolant

Don’t forget the radiator coolant—antifreeze, if you will. This coolant is not just antifreeze, it’s a rust inhibitor, fights boiling, etc. The coolant should be changed about every four years (consult the owner’s guide). Other items to check in the cooling system are the hoses—the heater hose and upper and lower rad hoses—the rad cap, and the thermostat. In addition, be sure to check the temperature sending unit, the sensor, and if your client pulls a trailer, the small transmission radiator which is needed to cool down the transmission fluid because of towing. When your client purchases a towing package for his vehicle, the radiator will be included in it. If there is no towing package, the radiator should be added.

All in all, the air conditioning system on your client’s vehicle should be thoroughly gone over in the early spring in order to catch any inconsistencies that may have occurred during the winter months. Then all will be in readiness for the hot summer months to come and air conditioning systems that work well.