You Can Fix Your Air Conditioning System--Here's What You Need

Your vehicle’s air conditioning system is not magic. Think of it as a refrigerator that keeps you nice and cool when it’s hot outside, just like your kitchen fridge does for your beer and last night’s pizza. Like any other system on your car or truck, you can repair it when things go wrong--and Summit Racing has the parts and tools needed to get the job done properly.

The actual process of working on an A/C system isn’t difficult for someone who knows their way around an engine, but is definitely not a project for the casual mechanic. We also want to caution you that opening up an A/C system can allow moisture to enter and any residual refrigerant to escape into the atmosphere and become a greenhouse gas. If either of those issues are a concern, let a professional shop work on your A/C.

Inside Your A/C System
Automotive air conditioning is a self-contained system that uses refrigerant to remove heat and moisture out of the air already in your car, making it nice and cool. Here are the basics on how the system works:

The compressor converts the system’s refrigerant into a high-pressure state, turning it into a liquid. The liquid refrigerant travels through high-pressure lines to the condenser, a small radiator where outside air absorbs heat from the refrigerant. The refrigerant moves to the receiver dryer/accumulator, which has a desiccant bag to remove moisture and impurities. It then flows into the expansion valve or orifice tube, where it becomes a gas again.

The clean refrigerant goes from the expansion valve to the evaporator (usually located in the dash), where it absorbs heat from the air passing through the evaporator fins. A fan blows this cool dry air into the passenger compartment to keep you comfortable. The refrigerant then travels back to the compressor and the process begins again.

These YouTube videos show you how a typical A/C system works:
• Eric the Car Guy: How an A/C System Works
• AC Avalanche: Auto Air Conditioning 101

Diagnosing an Ailing A/C System
The most common issue with an A/C system is loss of refrigerant due to leaks. That causes two problems. The obvious one is the air in the car getting warmer, the other is potential compressor damage. The refrigerant carries oil to keep the compressor lubricated during operation. If the refrigerant level gets low, the compressor could be damaged due to a lack of lubrication.

Checking system pressure while it is operating can tell you if the refrigerant level is low, but can’t tell you the actual level. Most leaks occur at the service ports on the high- and low-pressure sides of the system, but they can be anywhere a hose or line connects to a component, or from corroded metal line.

This Ratchets and Wrenches video does a nice job of explaining what can go wrong with your A/C.

Required Tools
The one tool you must have for diagnosing and recharging an A/C system is a manifold gauge. It measures pressure on the high and low sides of the system, and can be used to evacuate refrigerant from the system using a vacuum pump, and recharging the system with fresh refrigerant. Summit Racing carries manifold gauge sets from Performance Tool, Four Seasons, and OEM Automotive.

Summit Racing also has these A/C service tools:

• An OTC RobinAir Vacuum Pump works in conjunction with your manifold gauge tool to remove moisture, air, and old refrigerant from the A/C system. Summit Racing carries RobinAir pumps in several capacity ratings

• The Four Seasons R134A Canister Tap has a sturdy grip plus a brass valve that lets you control the rate of flow from a R134A refrigerant canister into the A/C system.

• The Lisle Air Conditioning Line Disconnect Tool Set is the easy way to disconnect most lines in an A/C system. It’s also perfect for quick-disconnect lines in fuel injection systems

• The Four Seasons ECV Compressor Service Tool is made for diagnosing the Electronically Controlled Variable displacement compressors found in modern computer-controlled climate systems. ECV compressors do not have a conventional clutch; the compressor shaft turns all the time, even with the A/C is off. Without a tool like this, it’s hard to diagnose if poor air conditioning performance is being caused by a compressor or a refrigeration system problem. This Four Seasons video explains how the tool works.

• After repairing and recharging the system, you’ll need a thermometer to measure how cold the air blowing into the passenger compartment is. A Titan or Summit Racing brand infrared thermometer will do the job.

Replacement Parts
If a compressor seizes up, a condenser or evaporator springs a leak, or some other A/C system part goes bad, Summit Racing has you covered. We carry top-quality OEM replacement parts from Four Seasons, ACDelco, Denso, Spectra Premium, Mopar Replacement, and Motorcraft.

You’ll also need compressor oil and R134A refrigerant. Changing your cabin air filter is a good idea as well.

While you’re in there, make sure to check the small stuff like accessory drive belts, blend doors and actuators, and blower motor resistors and replace them if necessary.

Adding Air Conditioning to Older Vehicles
You don’t have to boil like a lobster just because you have a classic vehicle, either. We carry retrofit climate control systems from Vintage Air and Scott Drake that make the upgrade to A/C easier, and won’t rob much horsepower while keeping you cool.

Resources
Here are some other YouTube videos you might find helpful:
• Eric the Car Guy: Recharging an A/C System
• Eric the Car Guy: How to Find and Repair A/C Leaks
• 2CarPros: How to Fix Your Car’s Air Conditioning