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Old 06-02-2018, 11:44 PM   #1
upon1
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Uneven Air bag pressure

Iím running a triangulated 4link on the back of my Ď55 with an accuair setup. For some reason I have way more pressure in one air bag than the other to keep truck level. Any ideas? Each side is set up exactly the same and am running the Firestone sleeve type bags.
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Old 06-03-2018, 10:28 AM   #2
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Re: Uneven Air bag pressure

Is there significantly more weight on that side? (relocated battery etc). A few more psi to compensate for weight isn't strange. How much pressure differential are you seeing?
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Old 06-03-2018, 05:43 PM   #3
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Re: Uneven Air bag pressure

Preload in the 4 link. Are the links adjustable?
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Old 06-03-2018, 05:50 PM   #4
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Re: Uneven Air bag pressure

Weight is even, battery is actually on the side with less pressure.
What do you mean by preload in the four link?
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Old 06-03-2018, 11:32 PM   #5
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Re: Uneven Air bag pressure

You can adjust the load on the suspension by lengthening or shortening links.
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Old 06-05-2018, 07:47 AM   #6
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Re: Uneven Air bag pressure

Here is a great video on preload. The entire series is good. Yes it is drag racing but it all applies in understanding how all this works.
Jimmy
https://www.youtube.com/watch?v=yMY-8_lBTZ4
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Old 06-05-2018, 07:32 PM   #7
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Re: Uneven Air bag pressure

It doesn't seem quite so simple in reality. What about if the front requires a different amount of air psi for each side??

I get adjusting preload, but it seems there would be WAY more to it on a street based 4-bar set-up vs. that race oriented 4-link. Typical street air suspension 4-bar set-ups w/poly type bushings @ each end aren't as adjustable (most only allow adjustment @ one end) & they're definitely not going to easily rotate to know if there's pre-load before making any adjustment.

When I did the 4-bar for my dually, I made jigs for the upper bars length (& lowers) to know each side/all 4 were equal/exact. I then installed everything & measured for square. I tweaked as necessary for getting things perfectly square. When they did the alignment, one thing I was worried about was the rear thrust angle & the 2 techs that did the alignment were impressed w/how tight/close the thrust angle was where I was afraid I might be off.

The alignment went w/o issue. But, my truck requires 10psi split up front & 20psi split out back. Also.... it's on opposing sides (pass front requires more psi; drivers rear requires more psi to be dead equal @ all 4 corners as measured @ the wheel opening lip (measurements validated pre suspension swap as well).

Thoughts?
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Old 06-06-2018, 12:47 AM   #8
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Re: Uneven Air bag pressure

PG thanks for that link. I didnt know about all of his videos. Ive been watching non stop for an hour.
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