I have the new PURest Air Dryer service instructions for the Multi-Treatment Cartridge Kit.

Looks simple enough, my question is the access. Is there enough room to remove the four bolts and lift the canister up. Where do you remove it to. Hardly any room to the rear or front of the canister. Should I remove the three bolts that hold the entire assembly onto the frame, lower the assembly and then remove the canister for the cartridge service?

Freightliner XC Chassis, 34ft coach.

Thanks

Hi Gary,

I have a Microsoft Word file with a few pictures on how to chance the Haldex dryer canister. If you would like a copy, email me rbdtanasi at yahoo dot com and I will be glad to send it to you.

Gary, below is one of the best writeups I have seen Here

And there are others who have contributed. I have personally changed my filter on our 2004 Journey 36G and elected to do it on the MH and not the work bench. It went OK. I used a hydraulic jack to help me reloate the Dryer into its correct bracket location. Below is my typed copy of the original document found a the above url. Check out the original as it come with photos. I wish I could give the original author the credit but did not get the name.

Goes without saying, and which I have to constantly remind myself, work safe. Also, every MH is different so you will want to analize how closely your MH is to these instructions and modify accoringly. And hopefully someone who has your unit might add to this. SteveG

"Skills Required: Strong arms to unscrew canister, strong hands to reconnect clamp.
Parts Required: Haldex DQ6026 kit, about $130. (smaller kit DQ6022 no longer available)
Equipment Required:
1. Large filter strap wrench,
2. small torque wrench,
3. the following sockets: tall 3/8" 5/16" 9/16" tall 11/16",
4. regular ratchet,
5. medium flat-head screwdriver,
6. (rare) 5/16" square (Robertson) bit,
7. paper towels,
8. degreaser spray,
9. latex gloves,
10. silicone pipe sealant.
11. hydraulic jack to help with re-install (SCG)

Time Required: At least 2 hours first time.
1. Release all air from system using three halyards located near passenger side of generator base.
2. Loosen large Desiccant Canister (1) using the filter strap wrench, but do not remove yet because there is insufficient clearance at top and the likelihood of grime falling down from the overhead wiring. Expect to use a lot of force but make sure you turn clockwise looking from underneath.
3. Remove the small air line (4) using a 9/16" open end wrench after removing grime from around it.
4. Disconnect the heater wire connection (8) by lifting the locking tab slightly on one side and pulling.
5. Remove the bracket bolt (Cap Screw in the DQ6026 instructions) on the bottom of the assembly (5) using the 9/16" socket.
6. The Pressure Relief Valve (2) can actually be removed by slipping a box end 11/16" wrench over the end and removing the valve and wrench together, but it would be easier to remove with a socket as shown below.
7. Open the strap clamp (3) fully using the 3/8" tall socket.
8. The assembly will still be connected by two air hoses, but it can be gently pulled down and tilted forward to allow easy removal of the Desiccant Canister and visual inspection of the cavity, after cleaning around the outside of the old filter first.
9. Reach inside and pull out the white Coalescing Filter by pulling on two of the four plastic tabs.
10. Install the new o-ring on the new Coalescing Filter, apply silicone grease, and insert. Be sure to push it all the way down like the old one.
11. Apply silicone grease to the large Desiccant Canister outer seal and then screw on hand tight for now.
12. Remove the old Pressure Relief Valve (2) if you haven't already, and install new one using 11/16" socket to 15 lb-ft torque.
13. Replace entire assembly back onto the lower bracket and reinstall bolt (5) using 9/16" socket to 30 lb-ft torque. (SCG used hydraulic jack to help with this)
14. Reconnect strap clamp (3) and tighten to 6 lb-ft. Be careful not to get air hose or heater wires under the clamp.
15. Reconnect small air hose (4) using 9/16" open end wrench.
16. Reconnect heater wiring (8).
17. Tighten Desiccant Canister (1) pretty much as far as you can go with the strap wrench around the base.
18. Remove the three screws holding the old Purge Shield (6). Use the flat-bladed screwdriver to pry the shield gently around the edges, a little bit at a time because it's stuck on and fragile.
19. Replace shield gasket, new plastic shield, and metal plate. Torque screws to 3 lb-ft after making sure the heater and gasket are resting loosely underneath the shield.
20. Remove single Pipe Plug (7) using 5/16" Robertson bit, drain contaminants if any, apply pipe sealant to threads of plug, and reinstall, tightening to 12 lb-ft torque.
21. Power air system back up. Test front halyards for sticking valves from prior dump operation.
22. After system airs up fully, turn system off and verify no air leaks from replaced components.
Note: This is what 3-1/2 year old filters can look like when only operated in dry climates: almost new. Your mileage may vary. If your filters look gummed up, you need to shorten your replacement interval."

I recently changed my Purest air dryer, with the help of a mechanic. We did remove the 3 bolts to be able to lower the whole dryer, but the problem was the one air hose that has the slip-type connection-it wouldn't slip. So one of us held the dryer while the other one removed the 4 bolts in order to lift off the top. It would have been so much easier if we could have removed both air hoses. When I called Gaffney to ask about the procedure, they said they change the filters all the time without removing the 3 bolts. Can't imagine how they do it without getting dirt and grease in it while reinstalling the new filter. Good luck, I'm just glad it only has to be done ever 3 years.
Wagonmaster2

Thank you for the replies.

I first loosened the four canister bolts, then removed the three frame bolts and with dryer in hand I replaced the canister filter. The job took aobut two hours and I din't have to remove any hose lines. This was a dirty job because the grease from the drive shaft coated the canister with grease and of course dirt debris. Next time I will clean the canister first and then R&R.

All-in-all not a bad project. Thanks again for the replies.

I just rebuilt mine recently and only undid the strap and bottom bolt. As the process is documented I won't go into that but the best things I did for prep were clean it off first and then I backed on 2x12 and then to 4x12 and then extended the jacks a little. It gave enough room to make the job easy. If you are only tipping it, use a light and mirror to see the condition down around the turbo valve. For the safety stands, I have a very substantial towing bumper, so put enough timber stands under it to hold a train

Gary - I sprayed my canister with Simple Green and the garden hose at least 3 times before attempting the removal and it was still a messy job. Even reaching the 4 bolts before getting the 3 mounting bolts out would be a hard reach, I don't see how you managed to reach over and around the rear axle to do that. And once you get the 3 bolts out you have no leverage on the 4 bolts. If the mechanic hadn't of had a small air impact wrench I'm not sure we could have turned the 4 bolts as tight as they were. If they had tried, I'm sure Freightliner could have managed a more inaccessable place to mount the dryer.
Wagonmaster2

Additional good suggestions, raising the coach on blocks of wood would have helped; also, I am going to purchase a small impact wrench. I've needed one in the past on projects and didn't realize someone makes a small impact.

I do enjoy working on the coach. Thanks again.