mmulvenna Report post Posted February 3, 2012 Recently purchased a 2004 Monaco Dynasty with Cummins 400 ISL. For piece of mind and to have a starting point for maintenance I am in process of changing all the filters. I am at the point of replacing the Air Dryer and want to be sure I am doing it safely. I have raised the coach with the air levelers so I can get underneath it to access the filters. If I remove the air dryer/filter will the the coach remain at the height I positioned it with the air levelers? Don't want to be underneath it and have it drop on me. Thanks for any suggestions anyone is able to provide. Mike Share this post Link to post Share on other sites
smokeater75 Report post Posted February 3, 2012 Hi Mike, I have a air and hydraulic system on my 2003 Windsor. If I am going under the motorhome I use the hydraulic jacks and then I use steel jacks just in case something happens. I had my filters replaced this past fall at a Cummins dealer. I don't mess with things on the motorhome that I don't have a 110% confidence in doing. That aside I wouldn't go under the motorhome for any length of time without steel jacks supplementing what ever system I was using for lift. Just my 2 cents Smokeater75. Good Luck. Just to clarify when I say steel jacks, I'm talking about supports. Share this post Link to post Share on other sites
hermanmullins Report post Posted February 3, 2012 Mike, Welcome to the Forum. I'm sending this out to any and everyone that wants to work under their own coach. Go out and buy the best Jack Stands you can buy. Make sure they are capable of supporting the weight of your coach. And NEVER, NEVER get under your coach without them in place. FMCA is losing enough members due to the economy. We don't want to lose them to accidents. Be Safe. Share this post Link to post Share on other sites
wolfe10 Report post Posted February 3, 2012 One other observation about air dryers. From a cost standpoint, FACTORY reman air dryers are a good, safe way to go. Repeat FACTORY (as in the company that made them), NOT someone else who rebuilds them, perhaps using overseas parts of dubious quality. I have seen examples when working with Bendix of poor quality aftermarket dryer rebuild parts. Brett Share this post Link to post Share on other sites
blakeloke Report post Posted October 28, 2015 Resurrecting this post (appreciate the insight Brett & Herman),After many years of not using our coach due to overseas and out of state work, we are newly retired and back on the road. And, we just reinstated our FMCA membership.To start, we have a 2005 40' Monaco Windsor that we bought new from a dealer in California. We just returned from our first real retirement road trip yesterday which entailed Houston to California via Interstate 10 with a return via Intestate 40.Upon leaving Tucumcari on Interstate 40 the coach gave us a Low Pressure warning buzzer at 60 psi. After a couple of minutes oftrying to build up pressure on the side of the road (trucks and traffic @ 75 mph)I decided to move slowly along the shoulder to the next off ramp which was several miles away. Fortunately I could run without the brakes locking as I had 30 psi at about 1300 rpm.After pulling off the interstate I was able to build up pressure to normal operating range. Unwilling to carry on with the trip without having a professional look at the air system we found a great repair shop in San Jon NM. (Terry's Service Center). These folks repair over the road trucks.Within just a few minutes of rolling to their yard, the owner had me pull into one of their bays. They put the coach on their lift and started to diagnose the issue. After pulling the air dryer filter they found it to be full of water condensation and oil. They also inspected the dryer body and found it to be clogged with the same gunk. They pulled the drain lines from the receiver tanks and found the tanks to be clear of debris and condensation.So, a new filter and thorough cleaning of the dryer and we are on our way back to Texas. I have an appointment with an RV repair facility this week for several minor issues but a new or "factory" rebuilt dryer and line cleaning is first on the work order. Lessoned learned for me is to have the air dryer filter changed regularly and the dryer body inspected at the same time.Although I'm very keen with respect to maintenance issues I just haven't had the time to run through the systems with a fine tooth comb. I'm hoping retirement will afford me the time now.Safe Travels!Blake Share this post Link to post Share on other sites
jleamont Report post Posted October 29, 2015 Blake, I recommend replacing the dryer with a factory rebuilt unit. The cost of them is reasonable and the quality is much better that someone trying to rebuild the old one in your coach. Just add the filter replacement to your list of things to do, thats what I have done so it doesn't get forgotten about. Good luck Share this post Link to post Share on other sites
obedb Report post Posted October 30, 2015 Why do air dryers fail on motorhomes? They frequently last for years on tractor trailers. Just curious. Can we do something to prevent failures? Share this post Link to post Share on other sites
tbutler Report post Posted October 30, 2015 Maybe they fail because we hang out in the swamps! Seriously, our vehicles frequently are parked for months at a time. Run, then parked again for a week or two. Who knows? I do know that there are other engine components that don't last as many miles as TT engines do, simply because of the nature of the usage pattern for motor homes. Share this post Link to post Share on other sites
bm02tj Report post Posted October 30, 2015 Transport trucks should be doing the filters every year and we should be every two to three years. and again how you use it and where you go Share this post Link to post Share on other sites
jleamont Report post Posted October 30, 2015 Obed, mine failed due to lack of service from the previous owner. I would have heard it purging and known it needed to be serviced. When I bought the coach in 5/2014 it wasn't purging, I thought it wasn't equipped, after crawling around under the unit I found the dryer hidden inside a make shift box. Since they are fairly inexpensive I opted to replace the unit rater than rebuilding it, I got lucky, the desiccant wasn't compromised. My coach had an older version of the Meritor SS1200 dryer, I installed a remanufactured Meritor SS1200. From what I could see it was hidden by some genius that enclosed the unit in a wooden box, my guess is so they wouldn't have to hear it cycle. Needless to say I removed all of the surroundings. They also had the governor set to 110 psi which I adjusted to 125psi. Now when it purges if you are anywhere near the passenger side rear wheel area you jump out of your shoes, just the way I like it. Unrelated but when I bought the coach it was "turnkey" completely serviced and all ready to go. You should have seen all of the stuff that was missed. Share this post Link to post Share on other sites
obedb Report post Posted October 30, 2015 Talked to a trucking buddy of mine who is also a trained diesel mechanic. He agrees with me that air dryers didn't start to show up on trucks until the late seventies or early eighties. We drained our tanks at least daily or several times a day if we had easy to reach lanyards. I remember pulling on the lanyards when I stopped for coffee. Of course they are easier to reach on a truck. So I spent 15 or more years of my career without them. How did we do it? Share this post Link to post Share on other sites
blakeloke Report post Posted November 2, 2015 Thanks jleamont......Brett also recommended same. Will heed your all's advice! Blake Share this post Link to post Share on other sites
jleamont Report post Posted November 2, 2015 Thanks jleamont......Brett also recommended same. Will heed your all's advice! Blake Your welcome. good luck. Share this post Link to post Share on other sites
obedb Report post Posted November 3, 2015 Our air dryer is also a Meritor. Probably could not be in a more difficult place to service or replace. Governor set at around 130 according to pressure gauges. Discharge bores a hole in a gravel site. My question is what causes the apparent premature failures based on what I am hearing. Owned my last truck for over 7 years and the dryer was trouble free. Coach now has a little over 24,000 miles on it. Typically put five times that and then some in one year on most rigs that I drove. Over the years I recall replacing just one dryer. Share this post Link to post Share on other sites
jleamont Report post Posted November 3, 2015 ObedB, I believe it is lack of maintenance. In the world of RV's they do not get used as often as a road tractor, valves stick from the moisture and lack of use and they stop working. My old dryer I took apart just to see what the inside looked like after 12 years, it looked like you reeled it in on your fishing line, gummed up rust inside. On the road tractors at work we see heater failures and heater electrical connection failures, we replace the cartridge every year if the heater works. Any valve concerns, leaks or heater failures we swing the entire dryer. During our four PM's per year we test the heaters (ohm test), check the electrical connector for signs of high resistance (burning of the plastic melted wires etc.) Otherwise no concerns. As you often read on here if its an older unit with low miles you have more of a concern than a higher mileage unit. same applies to the air dryer....my guess. Share this post Link to post Share on other sites
obedb Report post Posted November 4, 2015 You have convinced me. I prefer to do as much work on our coach as possible, but I believe that I will have a nearby RV repair center replace it. Planning a trip to Montana next summer and I will eliminate a worry by doing that. Thank you for the description of the dissassembly. Share this post Link to post Share on other sites
wolfe10 Report post Posted November 4, 2015 Actually, I would strongly recommend not using an RV facility to service/replace the air dryer. This is a common item on OTR trucks and a chassis or truck dealer would likely have techs who do this all the time, not once a year. Just my two cents, but if 6 years old, I would replace with a factory reman (i.e. the factory who made it, not "almost fit parts" installed by Bubba) dryer. Then, at three years, merely replace the filters. Then at 6 years a factory reman... Yes, if operated up north on salty roads or parked on a beach, probably to the factory reman every three years. Share this post Link to post Share on other sites
jleamont Report post Posted November 4, 2015 Great service interval recomendation Brett. Thanks, Joe Share this post Link to post Share on other sites
