310 Rear Airbag Replacement

[Magnet18]

As requested, photodocumenting and expanding upon the process as I do my 310.

I ordered firestone airbags part W01-358-5412

Got a start on the replacement today. Blocked the frame up by the lift hydraulics and spent an hour vacuuming up spiders. At least I don't live in Texas!

The bottom is held in by just one bolt, the top by two.

As others have pointed out, the top bolts can be removed without cutting an access hole in the floor above. But since I'm replacing my floor anyway, I went ahead and cut a hole to make the job easier, and to get pictures.

A pdf detailing the setup is attached

[Magnet18]

General photos of the setup, hard to get a good one without a fisheye.

[Magnet18]

Picture of the bottom
Picture of the top
If you need to cut an access hole, line up with the back of the wheel well and go as close to your drawers/walls as possible

[PeterH-350LE]

Originally Posted by Magnet18

As requested, photodocumenting and expanding upon the process as I do my 310.

I ordered firestone airbags part W01-358-5412

Got a start on the replacement today. Blocked the frame up by the lift hydraulics and spent an hour vacuuming up spiders. At least I don't live in Texas!
......

Yeah, down here in Texas, I have to pull Snakes, Scorpions, Armadillos and the occasional Skunk out from under the 350 on a daily basis, NOT!
But here is a tip once you re-install the brass fittings: Use teflon tape on the thread. It serves as lubricant even on compression fittings!!

[Magnet18]

Originally Posted by PeterH-Airstreamer

Yeah, down here in Texas, I have to pull Snakes, Scorpions, Armadillos and the occasional Skunk out from under the 350 on a daily basis, NOT!
But here is a tip once you re-install the brass fittings: Use teflon tape on the thread. It serves as lubricant even on compression fittings!!

I was thinking more about the black widows

[cmadmaxman]

Rob, if you have the means to do it I welded angles on both sides of the beam to help support the bottom of the air bags better. The later models of this system had them on em.

[Magnet18]

Originally Posted by cmadmaxman

Rob, if you have the means to do it I welded angles on both sides of the beam to help support the bottom of the air bags better. The later models of this system had them on em.

Thanks for the pictures
Looks like a good idea, flux core only and I'm not exactly good at it unfortunately, I'll give it a think though, seems a lot less flimsy

[Magnet18]

Got back to it this afternoon. Can this job be done without cutting a hole in the floor? Certainly. Do I recommend it? Well, after 30 minutes on my back with rust and spiders falling in my face, and only getting one bold to turn a whopping one turn... I let the picture speak for itself.

After that I was done with removal in under 30 minutes, it really is just 3 bolts per bag and the air fitting.

Like Peter mentioned, it's easiest to rotate the whole bag to get the fitting off. I put the bag back in it's spot sideways and it wasn't a problem.

I decided to not re-use the original hardware, as the top bolts were rusty and the bottom allthread was quite obviously bent nastily

The old bags were so dry rotted that I can rip them apart with my fingernails

[Magnet18]

The replacement mounting hardware

High-Strength Steel Threaded Rod
Zinc Yellow-Chromate Plated, 1/2"-13 Thread Size, 6" Long
3313N43 2

High-Strength Steel Hex Nut
Grade 8, Zinc Yellow-Chromate Plated, 1/2"-13 Thread Size
94895A823 1 pack of 50 8.97
pack $8.97

Zinc Yellow-Chromate Plated Grade 8 Steel Washer
for 1/2" Screw Size, 0.531" ID, 1.062" OD
98023A033 1 pack of 25

Zinc Yellow-Chromate Plated Hex Head Screw
Grade 8 Steel, 3/8"-16 Thread, 1-3/4" Long, Partially Threaded
91257A630 1 pack of 25

Zinc Yellow-Chromate Plated Steel Split Lock Washer
for 3/8" Screw Size, 0.385" ID, 0.68" OD
91104A031 1 pack of 100

Grade 8 Steel Washer
Zinc Yellow-Chromate Plated, for 3/8" Screw Size, 1" OD
98026A031 1 pack of 50

[Magnet18]

The hole in floor picture

I just went from joist to joist so I could actually turn a wrench, and I'll clean it up and patch it here soon

[cmadmaxman]

Looking at your threaded rod being bent, you might really want to do the lower bag support! That was bent from the bags rocking on that narrow beam!

[Magnet18]

Originally Posted by cmadmaxman

Looking at your threaded rod being bent, you might really want to do the lower bag support! That was bent from the bags rocking on that narrow beam!

I was thinking the same thing!

Probably happened while they were deflated, still, since I'm already doing the leafs and transverse rod, might as well just pull the spring beam down and make sure it's done right

[Suspenderguy]

My apologies if this question was answered earlier in the thread. Do you know if the W01-358-5412 will replace the 1T14C-1 Firestone 2107 in a 1981 28' AS motorhome. Thanks.

[dadstoy]

Originally Posted by Suspenderguy

My apologies if this question was answered earlier in the thread. Do you know if the W01-358-5412 will replace the 1T14C-1 Firestone 2107 in a 1981 28' AS motorhome. Thanks.

I don't know what the difference between the two are, but I had mine replaced with the "5412". I have an '82 280 with '81 chassis.


If the tag is still on the air spring beam (part #21 in the diagram) you can get the model and serial numbers and call American Carrier Systems and they will let you know.

[Suspenderguy]

Thanks very much . If it worked on your '82' I'm sure it will work on my '81' . I'll follow up on it today. Cheers!