Ken Thompson Posted February 5 Share Posted February 5 I’ve been trying to track down the exact, correct part number for affordable air bags for the front and rear of my 2001 36’ Dynasty coach. I know it has 2 bags per wheel, but haven’t yet determined if they have 3/4” ports or 1/4” ports. I know I could just use a 3/4 to 1/4 bushing if needed. I would like to have them on hand before I tear into it. Thanks! Link to comment Share on other sites More sharing options...
Bill C Posted February 5 Share Posted February 5 My RV is slightly different than yours, but I think the ones I installed will probably work for you. Here is the link for the 3/4" air inlet: https://www.truckandtrailer.parts/contitech-as8897-monaco-001804591 Link to comment Share on other sites More sharing options...
Bill C Posted February 6 Share Posted February 6 One thing I forgot to mention. Three-quarter inch air inlet is too big so I purchased the adapter to bring it down to a quarter inch for each airbag. I also bought swivel 1/4” air connections to connect the airline to the bag. It was a lot easier with the swivel than it was with a stationary connector that you had to get just right to be able to connect the airline to it. Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 6 Author Share Posted February 6 1 hour ago, Bill C said: One thing I forgot to mention. Three-quarter inch air inlet is too big so I purchased the adapter to bring it down to a quarter inch for each airbag. I also bought swivel 1/4” air connections to connect the airline to the bag. It was a lot easier with the swivel than it was with a stationary connector that you had to get just right to be able to connect the airline to it. The swivel may be a good idea. Just don’t know about the quality of the fittings we get now days. I pride myself on not having any air leaks at all. I haven’t been back under there to determine if I have 1/4” or 3/4”. Thanks 15 hours ago, Bill C said: My RV is slightly different than yours, but I think the ones I installed will probably work for you. Here is the link for the 3/4" air inlet: https://www.truckandtrailer.parts/contitech-as8897-monaco-001804591 Thanks Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 6 Author Share Posted February 6 2 hours ago, Bill C said: One thing I forgot to mention. Three-quarter inch air inlet is too big so I purchased the adapter to bring it down to a quarter inch for each airbag. I also bought swivel 1/4” air connections to connect the airline to the bag. It was a lot easier with the swivel than it was with a stationary connector that you had to get just right to be able to connect the airline to it. We’re you able to find a fitting that is all brass, or was it partially plastic? Link to comment Share on other sites More sharing options...
Bill C Posted February 6 Share Posted February 6 Yes they are all brass. I got them from a local rubber and gasket business. Link to comment Share on other sites More sharing options...
jmatusic Posted February 7 Share Posted February 7 Having all six of mine replaced. I found the axle manufactures tag on each of my axles and called them to get the air bag part number that they originally installed, then found cross reference for replacement. A huge pain in the butt on my front axle. Drive and tag bags very reasonable, around $100 each, front I had to use bags from my manufacturer (Tiffin) at 800 each as I could not find a current in stock bag from anyone. Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 7 Author Share Posted February 7 3 hours ago, Bill C said: Yes they are all brass. I got them from a local rubber and gasket business. 👍🏻 Link to comment Share on other sites More sharing options...
Paul J A Posted February 7 Share Posted February 7 The front air bags have a 3/4" fitting because of the distance from the compressor. The rear use 1/4". Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 7 Author Share Posted February 7 7 minutes ago, Paul J A said: The front air bags have a 3/4" fitting because of the distance from the compressor. The rear use 1/4". 👍🏻 Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 7 Author Share Posted February 7 12 hours ago, jmatusic said: Having all six of mine replaced. I found the axle manufactures tag on each of my axles and called them to get the air bag part number that they originally installed, then found cross reference for replacement. A huge pain in the butt on my front axle. Drive and tag bags very reasonable, around $100 each, front I had to use bags from my manufacturer (Tiffin) at 800 each as I could not find a current in stock bag from anyone. You’re talking about Tiffin, not Monaco. They are on different chassis. Link to comment Share on other sites More sharing options...
jacwjames Posted February 7 Share Posted February 7 On 2/5/2024 at 6:14 PM, Ken Thompson said: I’ve been trying to track down the exact, correct part number for affordable air bags for the front and rear of my 2001 36’ Dynasty coach. I know it has 2 bags per wheel, but haven’t yet determined if they have 3/4” ports or 1/4” ports. I know I could just use a 3/4 to 1/4 bushing if needed. I would like to have them on hand before I tear into it. Thanks! Here is the air bag for my Windsor which might be same as your Dynasty, I have the same chassis. In 2021 when I was working on air leaks on my chassis I did a thorough inspection of my air bags, no real problems, no leaks, no excessive cracking. But they were essentially 20 years old. I decided not replace but did buy two spare air bags from Truck and Trailer Parts, ContiTech AS9376 Air Spring | Monaco Coach 8619 8108 14002 Product ID: AS64365 These have the 1/4" port. 1 Air Bag Chassis.pdf Link to comment Share on other sites More sharing options...
jmatusic Posted February 7 Share Posted February 7 47 minutes ago, Ken Thompson said: You’re talking about Tiffin, not Monaco. They are on different chassis. You’re right of course. I was offering a method to find original air bag specs by calling axle manufacturer. Link to comment Share on other sites More sharing options...
Bill C Posted February 7 Share Posted February 7 All my airbags came with a three-quarter inch fitting that needed to be adapted to 1/4 inch. All my airbags use 1/4 inch to fit the airlines off the airbags. Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 7 Author Share Posted February 7 1 hour ago, Bill C said: All my airbags came with a three-quarter inch fitting that needed to be adapted to 1/4 inch. All my airbags use 1/4 inch to fit the airlines off the airbags. 👍🏻 Link to comment Share on other sites More sharing options...
b_faster Posted February 7 Share Posted February 7 @jacwjames Are your front and rear bags the same? The bag you referenced is similar to my rears. My fronts are double convoluted type. W01-358-6905 | Firestone Airide Air Spring | Double Convoluted | 20 (truckspring.com) 2000 40 Windsor S Series chassis. Link to comment Share on other sites More sharing options...
jacwjames Posted February 7 Share Posted February 7 1 hour ago, b_faster said: @jacwjames Are your front and rear bags the same? The bag you referenced is similar to my rears. My fronts are double convoluted type. W01-358-6905 | Firestone Airide Air Spring | Double Convoluted | 20 (truckspring.com) 2000 40 Windsor S Series chassis. I believe they are all the same. I don't believe mine are double convoluted. Link to comment Share on other sites More sharing options...
Ken Thompson Posted February 8 Author Share Posted February 8 First of all, thanks to all that helped me out on the air bag confusion. I have now removed the 2 air bags on the front drivers side. They are both Firestone W01-358-9376 they both have 1/4” pipe threaded holes. They cross over to Contitech AS9376 which has the same 1/4”-20 hole. The Contitech AS8897 has the same dimensions, but has the 3/4”pipe thread hole. I haven’t investigated the rears, but would just assume that they would be the same. I won’t order them until I get one off. 1 Link to comment Share on other sites More sharing options...
buzz shamer Posted February 8 Share Posted February 8 WO 1 358 8897 fire stone Continental on the rear of mine Link to comment Share on other sites More sharing options...
zmotorsports Posted February 8 Share Posted February 8 15 hours ago, Ken Thompson said: First of all, thanks to all that helped me out on the air bag confusion. I have now removed the 2 air bags on the front drivers side. They are both Firestone W01-358-9376 they both have 1/4” pipe threaded holes. They cross over to Contitech AS9376 which has the same 1/4”-20 hole. The Contitech AS8897 has the same dimensions, but has the 3/4”pipe thread hole. I haven’t investigated the rears, but would just assume that they would be the same. I won’t order them until I get one off. I thought I had posted this before, but it must have been on "that other site" when I did my air spring replacement posts. I learned this when talking with a Monaco factory tech years ago. I was told that in the 90's Monaco used the 1/4" NPT port sized air springs in earlier years on the front with 1/4" lines. Rears were 3/4" port size with I believe 1/2" lines but later, around late 90's, determined that there was no significant difference in ride, handling or fill rates so just went with 1/4" lines all the way around. They already had a stockpile of both 1/4" port and 3/4" port air springs when they converted over to all 1/4" lines and therefore just used a reducer. Somewhere around mid-2000's they just went to all 3/4" port air springs and used reducers to the 1/4" lines as the costs and availability were better. When I have replaced air springs I have just used the ones with 3/4" ports all the way around and used reducers. My cousins 1998 Signature had 1/4" lines yet his friends 1996 Executive did have the combination of 1/4" lines and the larger lines for the rear, again, cannot remember if they were 1/2" air lines or 3/4" lines. I'm pretty sure they were only 1/2" air lines and the connectors were 3/4" NPT 90-degree to 1/2" nylon compression fitting. Long story, you will be fine running the 3/4" port sized air springs all the way around with reducers to 1/4" NPT. Just be certain to use a good quality thread sealant for the threads and not tape. I'm not a fan of teflon tape. Link to comment Share on other sites More sharing options...
Paul J A Posted February 8 Share Posted February 8 Buy some brass swivel fittings for the air bags. So much easier to do. Known for being the best thread sealant to use for air suspension components, Loctite 565 Anaerobic Thread Sealant is available through AccuAir to allow you to add to your order to get your system installed correctly. This thread sealant should be used to seal all NPT style fittings on your system to ensure you have a leak-free install. This PST pipe sealant has controlled strength, is made for metal fittings, and it lubricates with PTFE. This .20 fl. oz. bottle will be enough to get all of your air system fittings sealed up. Air Bags [Springs} Sources https://vanhorntruckparts.com/ http://www.missionsupplyonline.com/ https://www.bigrigcomponents.com https://www.truckspring.com Sdtrucksprings.com Link to comment Share on other sites More sharing options...
PTTech Posted February 11 Share Posted February 11 Something to consider is the anerobic sealant I've used is basically permanent. It's like red Loctite. Link to comment Share on other sites More sharing options...
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