A/C repair in West Chester

Why the air isn't cold

• The refrigerant is low. An A/C system is sealed. It does not use refrigerant up — if it is noticeably low, it leaked.
• The compressor is not pumping. Most European cars have a compressor that varies its output with a control valve instead of clicking on and off. When the valve fails the compressor spins and does nothing.
• The condenser is damaged or blocked. It sits at the very front of the car and takes every stone.
• The cooling fan is not running. Cold on the highway, warm at a stoplight.
• A flap or its motor has failed. Cold on one side, warm on the other — though that can also be a low charge.
• A sensor or a wire. The system switches itself off to protect the compressor when a pressure reading looks wrong.

An A/C service here

1. Recover and weigh what is in the system. How much is missing tells us how big the leak is.
2. Pull a vacuum to boil out moisture and see whether the system holds.
3. Recharge by weight to the amount on the label under your hood, with the right oil.
4. Check the result — vent temperature and system pressures.

We have machines for both refrigerants. R-134a is in most cars through the mid-2010s. R-1234yf is in nearly every car built in the last several years; it costs several times as much, which is why the same service is priced higher on a newer car. The price depends on the refrigerant and on how much your system holds — give us your VIN or plate and we can quote it.

Finding the leak

A recharge on a leaking system is cold for a few weeks and then you are back. So when the charge is low we look for where it went: the system pressurized with nitrogen, an electronic leak detector, dye where it helps. The common places are the condenser, the compressor's shaft seal, the crimps and O-rings on the hoses, the service valves and — the one nobody wants — the evaporator behind the dash.

You get what we found and an estimate for the repair. A repair is not something we quote blind: two cars with the same symptom can need a ten-dollar seal or a compressor.

A/C in winter

Your A/C runs all year. Defrost uses it to dry the air, which is why a car with a weak A/C fogs up. Run it for a few minutes every couple of weeks through the winter; the oil carried by the refrigerant keeps the seals from drying out. A musty smell when it first comes on is the evaporator and the cabin air filter — the filter is a small job and due every 30,000 miles.

A/C questions

How often does A/C need recharging?

Rarely. A healthy system loses very little over the years. One that needs refrigerant every summer has a leak worth finding.

Why does my newer car's A/C service cost more?

It uses R-1234yf, a refrigerant that costs several times what the older R-134a does and needs its own machine. The label under the hood says which one your car has.

It's only warm at idle. What is that?

Usually airflow across the condenser: the cooling fan, its control unit or a condenser packed with debris. Sometimes a compressor that cannot keep up at low engine speed.

Is A/C work covered by your warranty?

Yes. A/C repairs carry our warranty of 3 years or 36,000 miles, whichever comes first.