Air Dryer Canister Removal

Barrier2 · 01-05-2010, 11:59 AM

Hi All, I posted a question about replacing the Air Dryer Canister on my 36' single slide 2001 Dynasty. Thank you for responding Walt2137.
I was wondering if I could remove the Canister Filter from the top gaining access by raising the bed and the hatch beneath it. Walt responded No I have to go under the coach.

This leads to another question how do I raise the Coach safely to gain access? I did a search and jacks are mentioned as well as jack stands. I have one 20 ton jack. What would be the best way to raise the rear? in the past I have used stacked 2x10s built into ramps ( that MH weighed 12,000 lbs) would that work? How high would the rear have to be raised? I will have to dump the Air to change the Air Filter. I have the three point RVA levelers. Should I first raise the Coach. place the 2x10s then dump? Will this be sufficient to work underneath??
Thanks for any suggestions?
Robert

Jim Stewart · 01-05-2010, 12:25 PM

Barrier,

On my Safari, I just raise the rear with the jacks until the tires were still touching but without them being off the ground. I then blocked under the the axle and dumped the air. I opened the manual air release valve in the back by my air chuck to make sure it was all out.

Be sure to block the front and rear of the tires to prevent roll as well.

I do not claim to be an expert on this and the extent of my experience as a Safety Engineer is to wear a belt on my pants when I lose weight. If I have told him wrong, please, someone step in.

After I finished, I aired up and removed all the blocks then retracted the jacks. In hindsight, I did check it with only dumping the air, and on mine, I had enough room to have done it without jacks or blocking. I do also have the upgraded suspension, so mine sits a little higher than standard.

walt2137 · 01-05-2010, 06:31 PM

Robert most everyone does dump the air before changing the air dryer filter ( I do also just to be doubly safe) but when the unloader valve unloads it depletes the air out of the filter. What I did with our coach with jacks is as Jim stated but didnt worry about the bleeder valve, on our coach with air leveling I just jack the rear up by airing up the rear bags blow the tanks down and with a strap wrench (I have had to use a 36" alum pipe wrench to get loose at times ) Most say to use jack stands but I must confess I never have, I make sure that I am always in a area that I cant get crushed if something does happen and I do all the maintenance on our coach and have the last 20 yrs.

saduncan1 · 01-05-2010, 07:11 PM

Call a truck stop if you have one nearby, TA. truckstop only charged me a half hour labor and they did it on their pit. $44.00

saduncan1 · 01-05-2010, 07:13 PM

Kenworth has Wabco dryer filters on sale $24.95 if that whats on your MH

Barrier2 · 01-05-2010, 08:08 PM

Thanks Saduncan1,
I live on Long Island NY there are no easy truck stops here, just $150 plus service shops where appointments must be made for everything particularly for large Motor Homes. Even getting a Vehicle Inspection & Emissions check here is difficult, at least that has been my experience.
I would also like to do certain items myself.
That price you gave for the Air Filters is great. Where did you get them for that price? I would like buy a couple.
Walt I do have a question that perhaps shows my ignorance. How do I just air up the rear bags? Don't the rear bags automatically level when the engine is on? Is there a way to just air up the rear?
Can I just raise the rear with the rear levelers as Jim said? Is the Unloader Valve separate from the Bleeder Valve
Robert

Snowman 1 · 01-05-2010, 09:17 PM

Barrier,

I don't have advice for you on safely crawling under your Dynasty to service the air dryer. I'll offer my experience with our air dryer a little while back.

We had our air dryer serviced a few months back when the coach wouldn't air back up after getting shocks put on. The shops that work on these beasts for a living almost always have a pit in the rear that they walk down into to perform service. Anyway, after watching an experienced mechanic remove this thing I was glad I wasn't underneath this 30,000 lb monster on my back trying to do something I had never done.

My air dryer canister was so plugged they told me it was doubtful the previous owners had ever serviced it. They removed the entire canister and took it to a work bench where they struggled for a half hour using tools I do not possess to get the filter apart. I'm talking air operated tools, heavy duty strap wrenches with 3 foot handles, etc. Some things are worth it to have the service performed. I admire guys who perform their own service on these rigs, but as Clint Eastwood put it, "A man has to know his limitations". And I know mine, especially when it comes to critical safety items like the air systems on diesel pusher motorhomes.

We have nearly identical coaches. They are heavy, complex, unforgiving pieces of machinery. My advice? Go to a shop, watch them service the air dryer this first time and then when it is time to service it again, you'll have a better idea of what's in store for you and whether it is worth your time to crawl under this thing to save a few bucks. I'm betting you won't. Good luck and be safe.

walt2137 · 01-06-2010, 08:00 AM

Walt I do have a question that perhaps shows my ignorance. How do I just air up the rear bags? Don't the rear bags automatically level when the engine is on? Is there a way to just air up the rear?
Can I just raise the rear with the rear levelers as Jim said? Is the Unloader Valve separate from the Bleeder Valve
Robert[/QUOTE]

Robert our dyn has air leveling, if your coach only have jacks just use the jacks as Jim said. The unloader is part of the air dryer and it automatically unloads at the pressure that the air governor is set, I think the bleeder valve he was talking about is on the bottom of the air tanks and you can deplete the air by fanning your brakes or the valve (dont use the air bleed switch on the dash as that will also deplete the air in the air bags and fanning the brakes or the valve wont)

Barrier2 · 01-06-2010, 08:40 AM

Thanks Walt, That does explain it. I will also use wood blocks under the axle.
I just hope I don't have the same frozen canister that Snowman had.
So far this Coach has shown to be very carefully maintained. The original owner had it for 8 years with no signs of abuse or neglect. Unfortunately I do not have a service record, but investigation on my part has revealed what has been changed and what has not.
Robert

Snowman 1 · 01-06-2010, 09:33 AM

Based on what I observed while ours was being serviced in Grants Pass, OR, I'd remove the canister, and take it to my workbench in the garage to take it apart, clean it real good and reassemble it. Like I said, took a couple guys to take this thing apart. Looked fine from the outside but the filter inside was rusty, filthy looking. The air dryer definitely did it's job.

walt2137 · 01-06-2010, 12:06 PM

Robert dont be surprised if it is hard to remove , if you have or can borrow a 36 alum pipe wrench you can get a stubborn canister off, be sure to put it at the bottom where it it wont crush. I have had to do this before on the Dyn as the canister had been on for a few yrs and not changed by the previous owner.

Rex · 01-06-2010, 12:43 PM

Snowman 1, sounds like you have the older type air dryer. About 2001 Monaco changed to a different type that only has one canister. The canister is not reusable or rebuildable. Just take it off and install a new one. Much easier service.