Frequently Asked Questions About Freightliner Classic AC Driers & Compressors

What years and models of Freightliner Classic trucks are these AC components compatible with?

Our AC driers and compressors are designed to fit Freightliner Classic XL and FLD models from 1990 through 2010. Most components are direct replacements for trucks with Sanden SD7H15 and SD5H14 compressor systems. Always verify your specific compressor model number (typically found on a tag attached to the compressor body) before ordering to ensure proper fitment.

How difficult is it to replace the AC drier myself, and what tools will I need?

Replacing an AC drier is a moderate DIY job that typically takes 1-2 hours. You'll need basic hand tools, a refrigerant recovery system, and new O-rings. The drier is usually mounted near the condenser with two refrigerant lines connected. Remember that the AC system must be properly evacuated before replacement and recharged afterward. If you're not equipped to handle refrigerant, we recommend professional installation.

How often should I replace my AC drier, and what are the signs it needs replacement?

AC driers should be replaced every 3-4 years or whenever the AC system is opened for service. Signs of a failing drier include reduced cooling performance, unusual odors from the vents, visible moisture or oil around fittings, and intermittent cooling. If your compressor has failed, always replace the drier as well to prevent debris from damaging the new compressor.

What's the difference between aftermarket and OEM compressors, and which should I choose?

OEM compressors are manufactured to original Freightliner specifications and typically cost 40-60% more than aftermarket options. Quality aftermarket compressors from brands like Sanden, Denso, and Four Seasons offer comparable performance and often include improved seals and bearings. Both come with warranties, but OEM units usually offer 2 years while aftermarket typically provides 1 year coverage.

Can I convert my R-12 system to R-134a when replacing these components?

Yes, when replacing your compressor and drier, it's an ideal time to convert from R-12 to R-134a. You'll need R-134a compatible O-rings, the proper PAG oil for your compressor, and retrofit fittings for the service ports. The drier must be R-134a compatible (most new driers are). Keep in mind that R-134a systems typically cool about 10-15% less efficiently than R-12, but the refrigerant is more readily available and environmentally friendly.