Frequently Asked Questions About Freightliner FLC120 AC Driers & Compressors

What year models of Freightliner FLC120 are these AC components compatible with?

Our AC driers and compressors are designed to fit Freightliner FLC120 models from 1988 through 2003. However, compatibility can vary based on your specific engine configuration and whether you have a factory AC system or aftermarket setup. We recommend checking your existing part numbers or contacting our support team with your VIN to ensure proper fitment.

How difficult is it to replace the AC drier and do I need special tools?

Replacing an AC drier typically takes 1-2 hours for someone with basic mechanical skills. You'll need standard hand tools, a manifold gauge set, and a vacuum pump. The most challenging part is properly evacuating and recharging the system. Many customers choose to have the refrigerant recovery and recharge done professionally while handling the physical replacement themselves. Always replace the drier when installing a new compressor to prevent contamination.

What's the difference between OEM and aftermarket compressors for my FLC120?

OEM compressors are built to original Freightliner specifications and typically carry a higher price point but offer guaranteed fitment and longevity. Aftermarket options from reputable brands like Sanden or Four Seasons can save you 30-50% while still providing reliable performance. The main differences are warranty coverage (OEM usually offers 2 years vs 1 year for aftermarket) and minor mounting bracket variations that may require adjustment during installation.

How do I know if I need to replace just the drier or the entire compressor?

If your AC system blows warm air intermittently or the compressor clutch engages but doesn't cool, you likely need a new compressor. A drier replacement is needed when you see moisture in the sight glass, detect a refrigerant leak, or if the drier is over 4 years old. Common signs of compressor failure include grinding noises, seized clutch, or visible oil leaks around the compressor body. Always replace the drier when installing a new compressor to protect your investment.

What refrigerant type do these systems use and can I convert from R12 to R134a?

FLC120 trucks manufactured before 1994 originally used R12 refrigerant, while 1994 and newer models use R134a. Conversion from R12 to R134a is possible and often necessary since R12 is no longer produced. Conversion requires replacing the drier, compressor oil, O-rings, and service port fittings. Our conversion kits include all necessary components and detailed instructions. Note that R134a systems typically cool slightly less efficiently than original R12 systems.