Kenworth 8 airbag question

[Rawze]

(05-27-2021 )W9L Wrote:  Hate to hijack but I am planning on replacing most or all 8 on my 93 W900L 8 bag pretty soon. And all the little cast plates between bag and frame. I have heard for years that if you go to bigger air lines feeding the bags that it improves stability and ride. The later trucks seem to come equipped this way oem. Does it require a different air bag to accept a larger npt fitting or do people use reducers. I would think reducers would create a bottleneck and negate a lot of the improvement?

My prostar used to be super-reactive on the air bags... I hated it and put restriction (needle valves) at my air bags and now it rides much nicer. Until I did that, my truck felt top-heavy all the time.

- I guess some people like it smoothed out.. and some people like it super responsive. Just throwing that in there.

[JimT]

Larger air lines will allow a greater volume of air to flow through, even with a reduction at a fitting larger lines would still help. Although you may still be limited by the input air flowing through the leveling valve.

I would highly recommend replacing all airbags at the same time. If one has worn out then most likely they are all equally worn.

Also, you don't actually need a jack to lift the frame, simply disconnect the bag to be changed and either plug the line or bypass that bag with a quick connect fitting. Then disconnect the leveling arm and manually raise the suspension using the other airbags. Much easier than fooling around with a jack. Plus, once all the airbags have been replaced you'll want to remeasure your ride height and adjust as needed.