when using WDH on Nissan Parthfinder R51, towing 2.8 ton van with ball weight of 250kg, does it matter how much air you have in your air bags so as to help keep vehicle level.

Appricatedscated your comments patrol03' however if you are caring some weight in the back of the vehicle then I believe the air bags will help level the vehicle before you hook up the van, would you not agree.

Depending on your vehicle a better alternative may be to fit heavier springs to carry your extra weight.  Airbags are a bandaid solution to worn equipment IMHO.

Having said that, my understanding is that the bags should be inflated to recommended pressure which should be in the bag literature before loading the vehicle.

We have Firestone airbags on 79 series LC ute. They improve stability considerably with very little pressure and help smooth out the bumps.

We use them at between 5-8 PSI normally (sometimes 10PSI) and each 1 PSI (if I recall correctly - as I can't find the reference) provides 60lb (about 28kg) of lift/support.

So you can see this is in the lowest recommended pressure range of 10-90PSI.

We have used them for 6 years now and no problem.

I have personally seen dual cabs with Polyair bags pumped up to 90PSI - accident just waiting to happen and several pics have been shown on this and other forums.

What I am saying is you need to know why you are looking to airbags and what makes them your choice over other options ie new or reset springs to match the load.

I advise against using them as vehicle levellers as that is not their purpose.

Do some research and make an informed decision.

I hope this info helps you to do that.

.. just FYI

Some time ago I had Pedders fit Firestone airbags to my Dmax. Since then, and with no more than 4-6  psi inserted, the tug and van have been a pure delight to drive.

Soon I hope to be somewhat more "static" in the far north-west of NSW where the primary demands on my Tug will change from towing a van to mainly travelling about in the bush and scrubby areas (van-free) to enjoy some of the remote outback fishing and adventure locations ..

Next week I will be having an old-man-emu kit fitted and suitably adjusted for my purposes without presenting an "overkill" of my intentions and will still retain the airbags in a manner that will allow me to engage/disengage them as required. This latest installation is being carried out by a professional service and by well credentialed fitters.

I'm quite happy to make these decisions after first placing it in the hands of the appropriate Professional resources ..

Many thanks for all the feedback, the Parthfinder is fairly soft in the rear end and the air bags have helped over the past 50,000km of towing, have been running 25 to 30 lb in them and kinda does the trick, we will be travelling full time next year so may look at putting heavier springs and gas shocks on the rear as a better fix.

Thanks all

Jackie

Yes, I use air bags in my Navara twin cab ute, very happy with the result.

Twin cabs of late from all manufacturers are very soft in the rear suspension, my first reaction was to go and fit stronger springs but when the vehicle was with out the caravan would of made it harsh to ride in so by fitting air bags filled to about 14 psi the set up seems ideal with the caravan.

Then adding load leveling bars has made it all work for me.

When I am running around empty I have about 8 psi. In them to help keep the bags shape, I did try totally empty of air but the bags them self still held the car off the springs and from practice I feel sure you are better to run some air in them, a better shock quality shock absorber would be a welcome addition as it has this feel of a uncontrolled bounce in it when empty.

I very impressed with my out lay to buy the air bags, there may be 200 pictures of cars with broken chassics, but for every one of these there is hundreds of happy customers using them.

Some will tell they never put more then 20 psi in them and others will go as high as 40 psi when towing there 5th wheels on the open road.

Sensible use of air bags in your ute will be a good investment, load levelers work fine after you get your tow vehicle set up right for towing. 

Using load levelers to adjust your tow vehicle ride height is a bandage solution.

I measured my tow bar this morning before and after placing the caravan on 190 kgs it dropped 20 mil.

Hope this information is of some help as I am a real user of air bags.

Hi Patrol03, yep could of paid out money to so called professionals but decided that my own experiences are better.

Tried a couple of emergency stops, the car and caravan come to halt skiding and carrying on as I would expect in a straight line, like to see how some one with more expertise would achieve a better out come.

I would also agree going to extreme pressures in the air bags may causes problems, as I had stated 14psi is reasonable even sub 20 would be good but a friend runs 40psi when towing a race car 5th wheeler Brisbane to Southern states many times per year over the last 8 years car shows no sign of bending or cracking.

The continual showing of photos displaying cars with bent chassis is not a real judgment of the damages air bags do as not all cars had air bags. Biggest problem was grossly over loading, add speed show over.

I would still think first setting your vehicle up to tow and then buy tow aids is better then spending money on tow aids first as motor vehicles are not built or sold as tow vehicles, 

Tow aids are designed for once a year towers to do there yearly trip but for us that that are doing 10/20000ks a year towing they need to address there vehicle first and air bags are great way to achieve this by pumping up a little and then lowering the air pressure when running solo.

Getting back to the orignal question, how much air do you run in air bags. Most people I have come across somewhere between 10 and 18psi when towing or carring extra weight.