My wife asked me: "Why do you need every "Truck Toy" that Epic has!!!???"
Me: "Because it's cool honey!"
Wife: "But you don't even have a fifth wheel trailer!!!!!!"
Me: "I know...........but Epic has one!!"

Thanks brother!!

 

Epic

Thanks for the part number

 

I installed the #2535 kit in October. Now I notice they lean or tilt forward on the axle, pinching the bags at the top rear and bottom front. I re-adjusted the bags and they simply popped with a loud bang and tilted again after loading the truck and driving around town. Anyone else have this problem? I filled out Firestones on-line support form and have not heard back from them.

 

Disco,

Is it possible that the top of the airbag is not squarely on the upper bracket? There is a guide pin on the top of the bag that is supposed to fit into one of two holes in the upper bracket. If the pin is not in the hole, the airbag can rotate into a position that it is only partially contacting the upper bracket and may force itself out of position when inflated. I noticed this when installing mine and had to loosen the upper bolts and rotate the airbag until it literally clicked into it's correct seating positon. The instructions make no mention of this alignment. You can tell if it's out of alignment by simply looking at the contact between the upper bracket and the top of the airbag. If it seems that it is contacting the bracket on only half of the top of the airbag, that needs to be fixed.

Also, the instructions were clear about making sure the surfaces of the airbag and the brackets were parallel with each other and in as perfect alignment as possible. I'm assuming you don't have the bottom bracket tipping one way and the upper bracket tipping another way.

 

I have installed 3 pairs of these things and I can tell you that firstly, Epic is correct in the alignment tabs/holes. Make sure everything is seated. Secondly, it is impossible to get the bag brackets perfectly parallel to each other without doing some fab work. When done to the best of the ability by what is provided by Firestone has proved to be extremely reliable in my experience. And, if you look closely at tractor/trailer air bags for their air ride you will see that there often is a slight rake to them and this angle changes with suspension travel. The more that the suspension compresses, the more parallel the surfaces get.

Looking at the geometry of the truck chassis in relation to rear end sag, the center of rotation is very close to the front axle (pivot point) when the rear end is loaded, therefore, there is a slight change in driveline angle at the rear axle. This is why we have splines on the drive shaft.

Simply put, there is a requirement to have some variance in the tolerances when considering the angle of the top and bottom brackets for the air bags. It's a system in motion where angles change as we drive.

As long as your installation is correct according to all the things pointed out by Firestone, Epic, and others here, you should be fine.

 

There seems to be interest and questions that are creating a lot of traffic here, so I will post this thread too.

Obviously, Epic is king of the "How To" info but I have a few pics that may help someone. Just a couple more views of the brackets and some routing info for bringing air lines into the cab for a different set up.

Epic, I'm not intending to intrude here.

https://www.ford-trucks.com/forums/9...-air-bags.html

 

No problem rusch. I appreciate these kinds of contributions immensely. It's all about sharing knowledge after all.

 

Here's photos of the rear sag with 5 psi and 65 psi in the bags. The photos don't really show the difference very well. With the trailer on the hitch and 5 psi in the bags, the measurement from the ground to the fender flare is 41 inches. With 65 psi the distance is 43 inches so the airbags provide 2 inches of leveling. With the trailer unhitched and airbags at 5psi the truck is 44 inches. So the net effect with airbags inflated and 3,700 lbs on the hitch is to squat the back of the truck exactly one inch.

On the hitch with 5psi:


On the hitch with 65psi:


So there you have it.

 

Cool, thanks! I can actually see a difference in the snow line under your truck (even though the truck is moved slightly). I ordered my bags earlier this week, should be here on the first. I opted not to get the compressor, just going to run the lines into the fuel door as I won't be towing too much.

Just waiting on the rv dealer I ran into at the show to call...

 

Nice and level...looks great...if I drive to SLC will you help me put them on?

 

Absolutely, it would be fun. That's a heck of a drive though.

 

OK, so Rite Rites techs have seen the pics I emailed to them. They replied back saying they were surprised my lower brackets had not failed and to set the brackets to the "lowest setting" ie, you have 3 bolt hole heights to use, I used the ones that, according the instructions, were correct for "most trucks". When I watched Epics video, it appears that he has used the highest setting on the bolt holes. I though it said NOT TO DO THIS in the instructions? Regardless, I did what the tech suggested, but the "Tongue" from the spring assembly prevents me from using the lower two settings. So, my conclusion, is, according to the tech, if I have these set up correctly, the lower bracket should fail! I've triple checked to make sure I have done everything correctly. The ride is fine, I am only concerned that the pinching on the bags will cause failure at 65mph! I'm at a loss for what to do, as no Firestone store in my area will even touch the bags. Getting frustrated that I am the only one having this problem!

 

There was only one configuration that would work with our trucks and that is what I ended up with. The key was making sure the lower airbag bolt was in the right position above the bump-stop bar. The "most trucks" configuration clearly would not work.Glad you figured it out.

 

Epic, I am not saying you did it wrong. You obviously know more than I do about this. I am stickler for instructions, and they instructed me not to set the bags up like that. I still haven't figured this thing out. It's driving me bonkers. Here are some pics at this link. Airbags pinching with original settings | Flickr - Photo Sharing!

 

Disco, no problem. I didn't take it that way. I had to make the same decision that you did during the installation because the instructions weren't really clear. In the end I thought it was more important to have the brackets firmly up against the springs and the bottom bolt in the proper position. The springs and the brackets are rated at 5000 pounds. There is no way they are going to be loaded to the max so I settled on the upper bolt hole position. So far so good.