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wheelsturnin 01-30-2014 03:06 PM

Dessicant filter change/Engine air filter change
2000 Newmar, Dutchstar 3856, Cat 3406, Does anyone know where the dessicant filter is mounted and anything I should be prepared for. I am also changing the engine air filter. Please offer advice on installation of both.


Hooligan 01-30-2014 07:55 PM

The desiccant filter is usually located inside the air dryer. IF your chassis used the Midland/ Haldex "Pure Air Plus air dryer, these instructions may be useful. DiscoveryAirDryer

It's important to drain all air pressure from the air brake system before working on the dryer.

wheelsturnin 01-30-2014 10:29 PM

Thanks, now I know what I'm looking at. It was right in front of me, easy access and another do it yourselfer project. The instructions and illustration are great. I find it very helpful to have a little insight before taking on the task, even if they provide instructions. My project for next weekend.

Stay well and happy trails.

DragRacer68 02-03-2014 02:25 PM

Let us know how it goes. I had Freightliner do my dryer service last year, kinda wish I'd have just done it myself.

wheelsturnin 02-03-2014 10:53 PM

It will be a few weeks. I finally got my step cover actuator problem figured out and need to complete that first. I hope to do the desiccant filter and the main air filter the same day. I have a few friends that are full time diesel mechanics, I hope to borrow their expertise while I knock this out. If I have the hindsight, I'll snap a few flicks for everybody who attempts this. It finally started raining on the SF Bay Area and I work outside, weather allowing I will get both done in the next week or two.

Lcrow 02-07-2014 03:04 PM

How do you access air filter for removal? Thanks

wheelsturnin 02-08-2014 01:00 AM

I assume you mean the desiccant filter that is attached to the air dryer, not the engine air filter. I haven't done it yet, but when it stops raining in the bay area, I will get it done. If you go back a few entries, you will find and entry by Hooligan with a link. The link will provide you pictures and some instructions. I assume each model and manufacturer puts things in a little differently. Its a good place to start. I will post again with pictures when I complete the job.

Yukon Jack 02-08-2014 08:06 PM

1 Attachment(s)
Reference is made to the questions about rebuilding the Haldex/Midland 'Pure Air Plus' air dryer, which is what I have on my 2001 Monaco Dynasty, and was also on my 1995 Dynasty as well.

As a suggestion, if your air dryer has not been serviced in a while, I would highly recommend that it be removed and given a complete service job by purchasing and installing BOTH of the following kits.

DQ6020 Lower Housing Major Repair Kit, includes purge valve, turbo saver & outlet check valve.
DQ6026 General Service Kit, includes Desiccant Cartridge, Coalescing filter, safety relief valve and misc hardware.

I would recommend that both of these kits be installed to return the air dryer assembly to its like new condition and provide you comfort of mind that it will operate at peak efficiency. This is critical, especially during the warmer, humid summer months to keep moisture out of the air system which is critical to provide good protection for the brake valves and components. This maintenance work will also help eliminate any chance of unexpected air leaks that will ultimately stop you dead in your tracks if the compressor can't recover faster than the air leaks out.

I can speak from experience of having to have 1995 Dynasty towed because I had replaced the filters with kit DQ6026 General Service Kit, but unfortunately did not change out the other kit (DQ6020 Lower Housing Major Repair Kit). Later that year I had a breakdown because the purge valve failed and I could not maintain sufficient air pressure until the air dryer had the DQ6020 kit installed.

As a side note, if after performing the air dryer service work and you have any issue with the compressor not cycling or unloading as you feel it should, then the next thing I would suggest is to replace the Bendix D2 governor air valve Unloader Valve which is really what controls the loading and unloading cycles of the compressor. These devices should be factory adjusted, but will typically cut out or unload the compressor at around 120 psi and should load the compressor at about 95 psi.

For your reference, I have attached a pdf illustration of the Air Dryer troubleshooting reference document.

Hope this information is of assistance and Happy RV'g.


wheelsturnin 02-08-2014 08:43 PM

Thanks Jack, this should do the trick. I will have a full time diesel mechanic watching over me. If he can't figure it out, I found out we have access to a freightliner trained tech. which is what my chassis is. Hopefully I will be able to pass on helpful info in the future as you do.

Safe travels

Hooligan 02-09-2014 05:00 PM

FWIW- I was told early on to carry a female 1/2inch npt brass connector to connect the in and output air lines together if the dryer failed on the road.

wagonmaster2 04-07-2014 11:04 PM


Originally Posted by Hooligan (Post 1906841)
The desiccant filter is usually located inside the air dryer. IF your chassis used the Midland/ Haldex "Pure Air Plus air dryer, these instructions may be useful. DiscoveryAirDryer

It's important to drain all air pressure from the air brake system before working on the dryer.

Anyone have any idea why the above link is no longer available? When I click on it the message just says "No longer available".

Hooligan 04-09-2014 05:26 PM

Looks like the link has expired.....
I uploaded the information to the chassis "Files" section here on IRV2.

wagonmaster2 04-09-2014 09:01 PM

When I clicked that link I got a message stating the Security Token was Invalid. What do I do now?

Hooligan 04-09-2014 10:08 PM

Don't know why the link does that. But- if you go to "Files" at the top of this page, the article, Midland Air Dryer Instructions, is in the "Chassis" section. Click there to download....
Hope this helps...

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