Peterbilt 567/579 AC Driers & Compressors

Frequently Asked Questions About Peterbilt 567/579 AC Driers & Compressors

What do the AC drier and compressor actually do on my Peterbilt 567 or 579?

The AC compressor pressurizes and circulates refrigerant through the air conditioning system, while the AC drier (also called a receiver drier or accumulator) removes moisture and contaminants from the refrigerant before it reaches the expansion valve or evaporator. Together, these components keep your cab's AC system running efficiently and help prevent damage from moisture or debris in the refrigerant lines.

How do I know if I need a new drier, a new compressor, or both?

Common signs of a failing drier include weak or inconsistent cooling, ice buildup on AC lines, or a musty smell from the vents. Compressor issues typically show up as loud grinding or clicking noises, the AC clutch not engaging, visible oil leaks around the compressor, or a complete lack of cold air. If you are unsure, a qualified technician can pressure test the system and inspect for contamination, which will confirm whether one or both components need replacement.

Will these parts fit both the Peterbilt 567 and 579 models?

Products listed in this category are cataloged for the Peterbilt 567 and 579, but exact fitment can still vary by model year, engine option, and cab configuration. Always check the part number, OE cross-reference, and listed specifications on each product page, or provide your VIN when ordering to confirm compatibility before purchase.

Do I need to replace the drier when I replace the compressor, or vice versa?

In most cases, yes. When a compressor fails, metal shavings and debris can circulate through the AC system and contaminate the drier and lines. Replacing only the compressor without also installing a new drier can lead to that debris cycling back and damaging the new compressor. Many technicians recommend replacing the drier any time the system is opened up, especially after a compressor failure.

Can I install an AC compressor or drier myself, or does it require a licensed technician?

AC systems are sealed and pressurized with refrigerant, so servicing them requires EPA-certified equipment and, in most cases, an EPA 609 certified technician to legally recover, evacuate, and recharge the system. While experienced fleet mechanics may have the tools and certification to do this in-house, most owner-operators will need a qualified HVAC or diesel technician to complete the installation and properly charge the system afterward.