Community Forums

jgdds · 02-26-2018, 11:17 AM

How often are you guys replacing the cartridge on your air dryer for your coach? The Bendix site says between 9,000-10,500 hours, or every 2, or 3 years depending on use. As you all know, most of our coaches are going to see nowhere near this amount of use. I'm at 5 years right now, and wanted to get your feedback on replacement intervals.

Thanks!

JG

2 Stroker · 02-26-2018, 11:37 AM

Have you checked your air tanks to see if there is any moisture or water in them, if you see any water change it. I have 4 years on mine and nothing but air and about 15k miles, plus it depends where you live with (High Humidity) air saturated with water.

2 stroker

jgdds · 02-26-2018, 12:17 PM

The only evidence of moisture I have is when the purge vavle opens for the first time or two, I get a little splash. After that, it is clean and dry. Tanks show no evidence of moisture either. I have about 25K on the coach, but I do live in the south where it is very humid!

jelag · 02-26-2018, 02:53 PM

The dryer cartridge is filled with a descent that absorbs water.... it will get contaminated from any tramp oils that come down the compressor line from the compressor as the unit ages and wears... any tramp oil that gets by the rings will end up on top of the piston and when the valves close and the compressor starts to pump again will be picked up under heat and sent to the dryer...

On a fleet of trucks, most owner replace the cartridge once a year, we did it as we started winter and the cold moist air...

you will want to pay attention to the weight of the cartridge if you buy an aftermarket brand as the simple way to skimp on the cost of to have less descent in the cartridge... so it will weigh less... I never bought OE stuff... way too expensive and we often would buy a case for under $30 per cartridge .... and often any of the truck dealers will offer winter specials on these items... BTW I've a lot of these go for over $100 a piece for those buyers who are not aware of their value..

If I'm going to buy one and store it... I don't buy it unless its sealed in plastic.. so that the moisture in the air won't contaminate it over the time it sits... or I drop in in a 1 gallon zip lock plastic bag...

BTW annually either pull the plug in the bottom of all 3 tanks or open the drain valves to make sure there is no water in the tank... if your a CDL driver that's required in you a.m. walk around...

jgdds · 03-18-2018, 08:36 PM

Thanks jelag for the info. I ordered a reman cartridge and plan to change it this next weekend. I am a Class B CDL holder and have checked my tanks many times and never found any moisture in them so I guess it is doing the job.

Dutch Star Don · 03-18-2018, 09:48 PM

Mine is a nightmare to change, so I've procrastinated. Mine is 4 years and will change it this month for the first time.

Old Scout · 03-18-2018, 10:04 PM

....yup, changing the AD-9 cartridge can be a PITA--the cartridge is screwed to a threaded stud in the assembly. I ended up removing the entire assembly, fastening it to a piece of plywood, and then fabricating an oversized strap-wrench and cheater bar to loosen the cartridge from the stud.....
PS--absent any signs of water or oil in your reserve air tank drain, have heard the bag holding the desiccant in the cartridge can deteriorate and release it into the system--so 4-5 years is probably a good time to change them out.....