air bag pressure and temp change

[maxum1989]

I just installed my air bags yesterday and I left 60lbs in them overnight to check the pressure this morning for leaks. I checked and they were at 55lbs. My initial reaction was darn, I have a leak. But, then I realized the temperature was quite different from when I filled them. When filled it was 50f but this morning it is only about 36f. Can I assume this temp change would cause my difference in pressure readings.

[maxum1989]

I took Wayne's (moderator) advice and PM'd him regarding our disagreement in how this thread was moderated. I apologized to him as he felt he was personally attacked. I believe we have reached an understanding in this matter. I now apologize to anyone else that didn't like the direction this thread ended up going in. Thank you.

[Reddog1]

maxum1989 wrote:

Reddog1 wrote:
Does it take much to understand that super springs have nothing to do with Air pressure?

Wayne
Molderator

Sure, but how about a "Lets keep it on track" kind of approach instead of just deleting without warning. And, considering Super spring offer a very similar remedy to suspension issues like air bags, one could argue that it is fair that they are brought up in a discussion like this. As the OP, I responded to the post you thought was off topic as I thought it was relevant.
My main beef was that so many threads on this forum turn very nasty and run on for pages with no moderators around and you chose this very civil one to throw your weight around.

Of course, this post is off topic as well so I guess it will be deleted. But, make sure yours disappears too as it has nothing to do with the question I started this thread with.

Very seldom if ever have I responded to a post like I am going to respond to this one, so consider yourself special.

1 The post I quoted above is a direct attack on me, as a person and moderator.

2 If you are aware of a Forum you would be happier with please enjoy it.

3 Your "beef" is not valid to me as the only Moderator on this Forum. With 338 post on this forum since you joined (03/29/2006), I question you have any idea as to how this Forum is moderated. Please refer to my second comment.

4 I am of the belief, most if not all participants on the forum are adults. As such, the expectation is to be reasonably aware that post can and will be deleted without reason. Fact is, I posted the reason I deleted posts. I thought my post was very clear and need not be posted on every thread.

5 As a moderator, I will not accept an attack on my character. If you disagree with my moderating, so be it.

6 No mater how hard I try, I see no connection between the post on Super Springs and the OP "air bag pressure and temp change". No doubt, it is not unusual for post to drift away from the OP, but the Super Spring post did not drift, it was Off Topic.

7 I made this post on an open forum only because it is a response to your post and attack on me on an open forum. Should you wish to continue this discussion, I suggest you do so through PMs. I will delete any further Off Topic posts.

Wayne
Moderator

[maxum1989]

Reddog1 wrote:
Does it take much to understand that super springs have nothing to do with Air pressure?

Wayne
Molderator

Sure, but how about a "Lets keep it on track" kind of approach instead of just deleting without warning. And, considering Super spring offer a very similar remedy to suspension issues like air bags, one could argue that it is fair that they are brought up in a discussion like this. As the OP, I responded to the post you thought was off topic as I thought it was relevant.
My main beef was that so many threads on this forum turn very nasty and run on for pages with no moderators around and you chose this very civil one to throw your weight around.

Of course, this post is off topic as well so I guess it will be deleted. But, make sure yours disappears too as it has nothing to do with the question I started this thread with.

[Reddog1]

Does it take much to understand that super springs have nothing to do with Air pressure?

Wayne
Molderator

[maxum1989]

The drop in pressure was on both sides. One side went from 60 down to 55, the other to 56. So I'm thinking temperature and the new bags settling in was the cause . I will keep a close eye on them though.

[AnEv942]

Though I also think new bags& line, temp difference, if you decide to start chasing source for leak with bubble solution (I usually grab some windex), bump pressure up. On ours after I initially installed, I determined I had a leak after a few days on right side. Couldn't find it. I finally found and the last place checked was one of the manual fill schrader valves itself. Removed the core, didn't see anything, reinstalled but stopped leak.

Um, was this drop on both sides?

[Reddog1]

maxum1989 wrote:
I just installed my air bags yesterday and I left 60lbs in them overnight to check the pressure this morning for leaks. I checked and they were at 55lbs. My initial reaction was darn, I have a leak. But, then I realized the temperature was quite different from when I filled them. When filled it was 50f but this morning it is only about 36f. Can I assume this temp change would cause my difference in pressure readings.

This is the subject of this thread. Other non-airbag pressure posts are off topic, and may be edited or deleted. If you wish, start a thread on the subject of your choice.

Wayne
Moderator

[tony_lee]

Assuming constant volume, Pressure changes according to change in absolute temperature.

60psi x 275/283 (ratio of absolute temperature) = 58psi

Small additional change due to air being heated above ambient by compressor and then cooling - say 1 psi, but relaxing of the airbags as mentioned might explain the rest

[tvman44]

Pretty much normal. Mine drop with the temp.

[maxum1989]

Gripnriprod wrote:
This from Tire Rack when discussing tire pressure: "The rule of thumb is for every 10° Fahrenheit change in air temperature, tire pressures will change about 2% (up with higher temperatures and down with lower)."
I would add that the air bags are "relaxing" after initial inflation. Continue to monitor the pressure. If the pressure doesn't increase when it warms up, you may have a problem.

excellent post. Thanks.

[Gripnriprod]

This from Tire Rack when discussing tire pressure: "The rule of thumb is for every 10° Fahrenheit change in air temperature, tire pressures will change about 2% (up with higher temperatures and down with lower)."
I would add that the air bags are "relaxing" after initial inflation. Continue to monitor the pressure. If the pressure doesn't increase when it warms up, you may have a problem.