Have you ever wondered how a receiver drier worked? Ben Skruch, our in-house engineer, answers this question in today’s post.
If you’ve ever looked over your Kenworth A/C system, you’ll notice a black canister component with A/C lines running in and out. This component is called a Receiver Drier. They can be located in different places depending on your year or model. Some are mounted right on your Kenworth heater box while others are mounted somewhere between your Heater box and the condenser. The name receiver drier pretty accurately describes what this component does. It receives refrigerant and it dries or removes moisture in your refrigerant. The receiver drier also contains a couple of different filters to remove any contaminants in the refrigerant. In my mind a receiver dryer is akin to an air filter, just for refrigerant. Just like in your air filter the receiver drier takes in the bad stuff and holds it so contaminants won’t ruin or cause inefficiencies in your system.
We like to know how things are put together at Shoreline Truck parts and we’ve got lot’s of good ideas on how to break things so why not bust one of these open and check how they work (Fig A). The above picture is one of the units we sell. I’ve broken his down further with a CAD diagram showing how the systems flows ( Fig B). The basic components consist of an inflow tube, filters and decadent beads. The filter portion works just as any filter would, but the decadent beads are probably the most interesting ( Fig C). Desiccant is hygroscopic and without getting too deep into the chemistry at work hygroscopic means it absorbs and holds moisture. Moisture in the A/C stem does a number of bad things you don’t want to deal with. It can cause expansion valves to freeze thus stopping or slowing refrigerant flow. Moisture can combine with refrigerant and cause an acidic solution damaging internal components. It can also cause high pressures in your A/C system tripping your high pressure safety switches or worse. Anytime your system has been damaged or a leak has developed the receiver drier needs to be replaced as desiccant will quickly saturate if exposed to the atmosphere.
Some other interesting things to know about the receiver drier on your truck. You’ll see some driers have different components. The main item you’ll need to be concerned with is why type of connection is used. The newer Kenworth trucks 2015 and newer use a nut, threaded rod and stat seal for attachment ( Fig. D) . Older trucks pre 2015 generally use a thread on style attachment with a rubber O-ring for attachment ( FIG E). It’s recommended that a lubricant is used on your seals and we recommend a product called Nylog that is compatible with all A/C systems and provides a thick lubricant to help prevent damage to the seal during install and provides good seals to the unit (link below). A couple of other items to note are the moisture indicator and the sight glass ( Fig E.) These items, though handy, are not required for your receiver drier to work properly and in fact are being phased out by many manufactures.
If you’re working on your A/C system on your Kenworth truck check out all of our AC products at Shorelinetruckparts.com. We have a large selection of heating and cooling parts from our famous stainless steel heater boxes to all the internals needed to keep your truck comfortable