Western Star 4700 Truck AC Driers & Compressors

Frequently Asked Questions About Western Star 4700 Truck AC Driers & Compressors

What do the AC drier and compressor actually do in my Western Star 4700?

The AC compressor pressurizes and circulates refrigerant through the system, while the receiver drier filters out moisture and debris from the refrigerant before it reaches the expansion valve or orifice tube. Together they keep your cab's air conditioning running efficiently and help protect the rest of the AC system from contamination and moisture-related damage.

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

Common signs of a failing drier include weak or inconsistent cooling, moisture or frost buildup on AC lines, and a musty smell from the vents. A failing compressor often presents as loud grinding or squealing noises, a seized pulley, visible oil leaks around fittings, or a complete loss of cold air. If you're unsure, it's a good idea to have a qualified technician inspect the system before replacing parts, since a bad compressor can sometimes damage the drier and vice versa.

Will this AC drier or compressor fit my specific Western Star 4700?

Fitment can vary based on model year, engine type, and cab configuration. Always check the listed specifications and part numbers against your truck's OEM part or VIN before ordering. If you're not certain a part matches your setup, reach out to our team with your truck's details and we'll help confirm compatibility before you buy.

Should I replace the drier every time I replace the compressor?

Many technicians recommend replacing the receiver drier whenever the compressor is replaced or the AC system is opened up for repair. This is because moisture and debris can enter the system during service, and the drier is designed to trap contaminants that could otherwise damage a new compressor. Skipping this step can shorten the life of your new compressor.

Are these AC driers and compressors new, remanufactured, or used parts?

We carry a mix of new and remanufactured AC components, and each product listing specifies which type you're purchasing. Remanufactured units are rebuilt to restore proper function and are typically a more budget-friendly option, while new parts offer the assurance of an unused component. Check the individual product description for details on condition, warranty coverage, and any core charge that may apply.