Roadmaster S-Series Suspension Air Spring/Air Bag Replacement

[Dr4Film]

51 minutes ago, Makalu said:

Now to find a decent replacement for my auxiliary auto leveling compressor. It died on me...

I purchased this Thomas one from Amazon.

https://tinyurl.com/34c5xvjx

I am in the process of rebuilding the entire HWH Aux Compressor fixture. I will remove all of the components, wire brush the platform and give it a good couple coats of black paint. Then I will mount the new compressor, new White-Rodgers Relay, and the new 90/120 Pressure Switch plus check the air dyer filter and spitter valve for proper operation. Once everything checks out and is working like it should, it will be mounted to the floor with sound dampening foam in the space between the Aqua-Hot and the Cablemaster Power Cord Accumulator. That location will allow me to service the unit easier than being mounted in front of the rear drive axle.

[Makalu]

59 minutes ago, Dr4Film said:

I purchased this Thomas one from Amazon.

https://tinyurl.com/34c5xvjx

I am in the process of rebuilding the entire HWH Aux Compressor fixture. I will remove all of the components, wire brush the platform and give it a good couple coats of black paint. Then I will mount the new compressor, new White-Rodgers Relay, and the new 90/120 Pressure Switch plus check the air dyer filter and spitter valve for proper operation. Once everything checks out and is working like it should, it will be mounted to the floor with sound dampening foam in the space between the Aqua-Hot and the Cablemaster Power Cord Accumulator. That location will allow me to service the unit easier than being mounted in front of the rear drive axle.

Smart move. Please post your completed setup when you're done. I'd be interested in seeing it. My (dead) auxiliary compressor is mounted right up by the front axle. So I'll probably be keeping it there as it's pretty far from the bedroom this way.

[Dr4Film]

1 hour ago, Makalu said:

Smart move. Please post your completed setup when you're done. I'd be interested in seeing it. My (dead) auxiliary compressor is mounted right up by the front axle. So I'll probably be keeping it there as it's pretty far from the bedroom this way.

Sure will! I will have the platform done this summer while Workamping in new Hampshire. Then when we get back home to Florida for the winter, I will complete the hookup of the power cable and the air line.

When I rebuilt the HWH on my previous Windsor that was located in back of the front axle, I placed it in the Fuel/LPG bay out of the weather. Here is a photo of that HWH Aux Compressor that the new owner is enjoying.

[jacwjames]

  In 2021  I inspected the airbags carefully, used soapy water and sprayed them down then used a bright light to inspect and take pictures.  Did not find any leaks and or damaged areas. 

But I bought and have been carrying 2 spare air bags "just in case".

With all the discussion on air bags and how to change them I decided to go ahead and pull one off and take a good look at it and also check the air bags that I bought.   My 22 ton jack stands came yesterday so I had everything I needed to tackle the job. 

To lift the coach up high enough to put the jacks stands I put a bunch of 10X10X1.5" under the front jack and raised the coach as high ad it would go.  When I first bought my coach the hydraulic jacks struggled to lift the front end and didn't come close to raising it get the tires off the ground in the front.  I found some info on line on how to increase the pressure, did that about ~8 years ago.  Now I can get the tires off the ground.  I put the jack stands under some vertical pieces just in front of the fuel tank bay.  I had ~1/2" to spare so after placing the jack stands I release a little pressure from the front jack and let the coach sit on the 2 stands and jack, ain't going anywhere. 

I decided to do the front passenger side, it wasn't too bad once I got the right size socket and tools gathered up.  The bottom nuts came right of with my 1/2" impact.  Removed the upper brush, that took 10mm socket and some extensions, had to battle the wiring loom there.  The back top nut wasn't as easy, had to use a open end wrench to loosen the nut and then used my 3/8" long impact to take the nut off.   Then used a open end wrench to take the airline fitting loose. 

Saved the worse nut for last, the front top nut is a bear to get to, had to take the front passenger side shock out for access.  Not a bad thing as I wanted to see if it still had a charge.  I know that the shocks had been changed before I bought the coach in 2008.  Anyone know what brand shock this is??

Ended up using a ratcheting swivel head wrench for that but had to use a cheater bar to get it loose and then ratcheted it off ~1/8 turn at a time.  I found that if I moved the generator forward I could kneel from that location and reach it. 

So got the bag out an inspected, put in the sink in my shop and washed it, it looks really good.  Not sure if I'm going to put the new one in or not.  A lot of work but it gave me piece of  

 

 

[jacwjames]

So I'll probably go ahead and put the new air bag on and see how it does.  I'll carry the old one as a spare. 

 

In the past I thought if I had one fail on the road I'd just change it.  After taking the time to remove the one air back I'm pretty sure I could do one on my rig.  I'm pretty much using the tool set that I carry but did have to go get my cheater bar from the garage tool box.  The one tool that I just bought and used was a ratcheting swivel head box wrench, pretty much need this for the top nut where the shock support is welded, nothing else will work due to location/size. 

Might have to get creative on blocking the rig, I can lift the coach with my jacks but to be able to work on it I'd need some spacers to put between the framing and axle carriers but it's doable.   I've seen posts of people doing that so while I got the rig lifted I'll do some measuring. 

[jacwjames]

Got the new air bag installed yesterday, it went faster then the removal process until I got to reinstalling the shock. 

Having the coach raised up high actually made putting the new bag in a little harder.  I didn't have to fight clearance.  I put the top nuts on the bag first since it was collapsed, then pulled the bag down and the threads barely came through the lower mount, had to force it through and start one nut, pulled it down with the impact and then the second nut.

When I looked at the nuts that I had taken off they all looked the same but the top one on the shock stud mount was a fine thread.  I had bought new nuts which worked on the air bag and bottom shock bolt but I could not get it to thread onto the stud.  Tried several time, it would start but after a couple turns it was stuck.   I was getting frustrated and know I had to not screw up the threads.  Just by chance I saw a nut that had rolled behind the week back towards my center jack, so I crawled back there and retrieved and when I looked at it saw it was fine thread.  When on easily.   Lesson learned there, I had read up on shocks and remember that the upper mount was different. 

Minus the top shock mount fiasco it probably would have taken less then an hour to put the new bag in.  

 

Here's how I placed the jacks under the coach to support it while working on the rig.  The jacks are 19" so it would have taken a lot of blocking to place anywhere in the front.  I placed a bunch of wood blocks under the front jack and lifted up and then slide the jacks under the same X-brace the front jack is attached to and the jacks are directly under a vertical brace so the structure was there.  After placing the jacks I bumped the hydraulic center jack down until the jacks were supporting the rig.  

Since I know know I don't have to be that high to change a back it will be easier next time.  These are the jacks I found on Ebay ~$153  https://www.ebay.com/itm/156212556409   They look the same as from other sources such as Lowes and/or HF.  I noticed that they've already increased the price ~$7 

The picture is upside down, IT AIN'T MAGIC

Edited July 20 by jacwjames

[cbr046]

Project Farms did a functional test on several jack brands, all the way to destructive tests.  Although automotive it gives an idea who makes the better brands, how they're made and how they fail.

https://www.youtube.com/@ProjectFarm/search?query=stand

- bob

[jacwjames]

From an engineering standpoint the jack stands are a good design.  The outer tube is welded to the bottom plate and has 4 gussets that provide stability.  Since I was on flat concrete the jacks were fairly all the weight is transferred straight down so the the stand is in full compression.  The inner tube is pretty substantial and uses the large pin to carry the weight.  Depending on the quality of the metal the shear strength of the pins are probably ~40K lbs per side so 80K per jack stand. 

The set of jacks is rated form 22 ton, since my coach only ways ~33K the set would theoretically support the whole coach if you could balance it on two jacks.  So I'm pretty comfortable with the capability of the jacks.

I guess the only way to know for sure is to do a destructive test.  I'm sure there is a safety factor, not sure what the standards call for.  I know in mine hoist applications we used a safety factor of 7 for man hoists. 

[Rheine]

This is badass engineering. Just what I needed to guide us through the project.  All the pics really helped too.

 

R