f-250 airbag questions

[tkrrox]

i just got airbags for my f250.....here are my questions....

1. is it better to have the upper plate parallel to the frame or to the bottom plate?

2. instructions say leave 5"-6.5" between brackets....what is the most the bags will flex? do i have to use limit
straps?????

3. what is the normal loss in pressure over a period of time?

4. is there any reason not to weld upper brackets to frame instead of bolting?

5. is there any noticeable result in vehicle ride with the lower bracket clamped to the spring??? (my brother's
f-350 has a custom spring plate that also holds the bag)

6. after i have them is it still necessary to use the weight distribution hitch???? (i have a 21' sandpiper)

7. anything else i should know about????

thanks for the input taryn kelley

[PerryB]

I've had Firestones on two different Ford F-250 CC SWB 4x4's (both self installed) and here are my opinions/observations. 1) The upper pad (ideally) should be parallel to the lower pad but this cants it quite a bit forward on the frame. On mine I split the difference -- Firestone says this is fine, and the resulting angle discrepancy is slight. Doing this lets you mount them higher and keeps you from drilling into the inset portion of the frame. 2) To get proper clearance/travel, you'll want to mount them as high as possible while retaining adequate clearance between the air-line fitting and the bottom of the bed. 3) Mine never lose any air pressure. The only time I've lost air was when I had a leaky Schrader valve. 4) DON'T weld the upper brackets to the frame!! All the stress/ load is imposed upon the vertical side plates of the mounting brackets. Welding a loaded stress line across the frame is just asking for future problems -- like a broken frame. Its just too easy to drill the holes and do it right. 5) I don't think the lower bracket will cause a detectable change in spring pack stiffness or ride height. Yes, theoretically by using this bolt/clamp method the ride height may be slightly reduced and spring rate stiffened up slightly, but I think you'd probably strip or break the bolts first. Just install them snugly and use nylock nuts so they don't work loose during spring compression. That having been said, what I did ( I have factory overload springs) was to use short bolts-about an inch long-and install them upside down, bolting the lower bracket to the overload only. It works great IF you have the overload springs. 6) Theoretically the airbags don't really reduce the need for spring bars -not to be confused with a sway bar- but I don't see your truck needing spring bars for a 21' travel trailer. A sway bar however, would be an excellent safety/stability item. Hope this helps. ---- P.S. the two trucks I did were an '02 and an '06 (current truck) so the frames should be the same as yours. Perry

[David C]

I'll attempt to answer some of your questions, numbered the same as you used.

1. Top and bottom mounting plates should be essentially parallel each other.

2. I cut 6.25" tall blocks of 4x4 as spacers to adjust bracket height. This also helps get them parallel before drilling or bolting things together. You do not want the bags to be stretched very far. The small studs appear to be glued/bonded into the rubber bag, and you do not want them to be torn out, so I approached the max extension height they suggest in mounting. That is why they suggest the truck not be lifted by the frame letting the rear axle assembly to drop to the max.

3. I do not know how long they hold a specific higher pressure. With temperature variations I know the 10 to 15 psi used as normal for running about town seems to hold for months, give or take a little loss every time I measure manually. On an longer trip at about a 50 psi setting (because of towing load), I did not add any air for over a month trip. Usally I change the air due to driving needs before I would ever notice a serious leakdown.

4. I do not weld here at home so that was not an option. However if due to ???? you replace the truck, you could possibly transfer the airbags if not welded.

5. I have not noticed any difference in ride at all after adding the airbags. I just know the truck now can be leveled - which I do notice.

6. The air bags may help the rear end to ride with less movement, but I did not really notice any stiffening of the ride.. The load in truck bed or towed would have more affect on the body movement of the truck. Air bags do not serve the same pupose as the weight distributing hitch. I would not expect to tow my trailer without the WD hitch. If you currently use a WD hitch, I would recommend you continue to use it.

7. When preparing for a tow trip, load your truck and trailer while not attached. Use the air bags to level your loaded truck first. Hook up the trailer and use the weight distributing hitch to again level the truck for the added hitch weight.

[brotherxb]

I have air bags on my 01 supercab with onboard compressor and it rode bad before and it shure didn't help the ride any after even with the 5psi sensor. It restrict's the travel of your rear suspension. Love the truck,but hate the ride. The ride mty is so bad I am thinking about putting a 4K dollar 4 link air suspension on it.

[tkrrox]

Originally Posted by brotherxb

I have air bags on my 01 supercab with onboard compressor and it rode bad before and it shure didn't help the ride any after even with the 5psi sensor. It restrict's the travel of your rear suspension. Love the truck,but hate the ride. The ride mty is so bad I am thinking about putting a 4K dollar 4 link air suspension on it.

has anyone tried pulling the overload fatt spring on the bottom and the next short one and the use ladder bars to keep from getting axle wrap????
i am toying with doing this, because i also can't stand how stiff the rear is...

[Nubbs]

Originally Posted by tkrrox

i just got airbags for my f250.....here are my questions....

1. is it better to have the upper plate parallel to the frame or to the bottom plate?

I installed mine with the upper and lower plates parallel.

2. instructions say leave 5"-6.5" between brackets....what is the most the bags will flex? do i have to use limit
straps?????

I am not using limit straps. I'm not sure what spacing I used between the brackets. I just installed the bottom bracket, attached the air bag to the bottom bracket, set the top bracket on the air bag and marked the frame. I had no air fittings in the bag when I marked the frame.

3. what is the normal loss in pressure over a period of time?

I plumbed my system with push lock fittings and dot air line. I have an on-board compressor mounted above the spare tire and a dump valve in the cab. Whenever I have a significant amount of pressure in the bags, there seems to be no pressure loss. When the bags have minimal pressure, less than 5 psi, and it is cold outside, the pressue will decrease over night. I think the fittings and hose expand/contract at different rates (just my theory) causing the pressure to bleed.

4. is there any reason not to weld upper brackets to frame instead of bolting?

I bolted mine.

5. is there any noticeable result in vehicle ride with the lower bracket clamped to the spring??? (my brother's
f-350 has a custom spring plate that also holds the bag)

I can't tell.

6. after i have them is it still necessary to use the weight distribution hitch???? (i have a 21' sandpiper)

Not sure, but I use the wd hitch with mine.

7. anything else i should know about????

I thought the extra money for the on-board compressor system was worth it.

thanks for the input taryn kelley

Answers above in blue.

[tkrrox]

thank guys i installed them and worked great...am definitely thinking about on board air....or at the least "T"ing them into one shraider valve....also i am toying with pulling my over load springs to see if i get a smoother ride..