AikenRacer,
Funny you should mention this subject. I JUST pulled my air dryer out of our '04 Itasca Horizon 36GD with the C-7 330HP CAT, about two hours ago. In our coach, it really wasn't all that hard. It sits right behind the rear axle and up a bit, on the drivers side. Probably the hardest part of removing it was, the large air hose. There's three. A large one, about 3/4" in size, that's basically a stainless steel braided line, that's attached with a swivel fitting.
A second one, that's plastic, 1/2" in size, that I think is attached with a "push" type release collar but, since I could not get the collar to push in, I just spun the fitting just below the elbow the plastic hose was in.
A third one, a 1/4" that's used for air control, is also plastic and, is held in place with a push collar too. I was able to release the tension on the collar, by pushing in on the hose and, that releases the tension on the collar. Then you push in on the collar and that releases the hose altogether.
Then, it was a matter of removing four, 3/8" x 1" bolts and lock nuts, that hold the whole mechanism to the frame of the coach.
Now, some will possibly "rebuild" or, service it while it's in place, attached to the frame. I however, did not want to do it that way. The primary reason is because there's lots of dirt and debris all around that air dryer. If you remove part of it, as in the large filter on top, you can easily cause debris and dirt/grease/sand etc. to fall into the cavity where that filter resides.
And, not to mention, the relief valve, a small component that has to be replaced when the air dryer is serviced. If that relief valve is facing the mounting bracket, as mine is, then you have no choice but to remove the entire air dryer and, do the service on the work bench because, the mounting bracket that is removed with the air dryer, has to be removed, in order to create clearance for that relief valve to be removed and, the new one inserted.
As of right now, I'm in the process of cleaning things up some. It was quite a mess. What would anyone expect, it's been under there for almost 11 years and, 60K miles. I know, I know, it should have been done way before this. We purchased the coach 3.5 years ago with 40K on the clock and, I know darned well that the gent who owned it before us, never touched it or, had it done. He had a hard time tying his shoes. (if you know what I mean)
I'm not sure about yours but, on mine, there is a service kit, which contains two different filters, a couple of gaskets, a purge protector, and a relief valve. That kit, the DQ6026 kit, cost me a whopping $65.00 on ebay, BRAND NEW. I just saw the same exact kit, at a vendor in Quartzsite a week ago for $134.00.
Now, in prep for you maybe thinking of doing the service work yourself, I'd crawl under there and, see if you can get the exact model number of your dryer and, see what kit is needed for service when the time comes. I've not taken mine apart yet to install all the new filters and parts. I'm just cleaning it all up so I'm not messing with a radically dirty unit while trying to install the components and not get dirt into any orifice.
I've talked with quite a few and, corresponded with more about doing this job myself. I received a lot of encouragement from all people. I've been doing all the maintenance and repairs on everything I've owned for decades and, have done some pretty serious work on this coach. This job so far, is rated as actually real easy, compared to what I've done so far. I'll post more when I disassemble it and, install the new parts and components and, re-install it in the coach.
Scott
