Firestone/polyair bags

Get an Airlift kit. They are better and have the lower protection pieces.

They do push top and bottom. That is how they work.

Quote:

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Originally Posted by steveG

Be aware that they aren't an air spring, more like a device to increase the spring rate. IIRC they're working by getting between the coils rather than pushing on the top and bottom like an air spring.
Been a while since i played around with pressures when I fitted them to the county, but from memory they tended to settle at their happy height after a bit of a drive - not necessarily the same height they were when first setting off.
These days I just put 25psi in them when fully loaded or towing the van, and about 4psi when not.

Steve

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The operation here is correct but they do give a bit of a push also.

30psi for mine basically stops the springs working! I only put a few psi in maybe 10 tops when using and I run no air in them when not being used despite recommendations - so far no issues in probably 15years of them being installed.