Coilrite Airbags

[UIZ733]

A question for those who have fitted airbags to their suspension for towing purposes. When the airbags are inflated to the correct pressure for towing, does it alter the height of the vehicle at the rear? If the answer is yes, what measurement (in mm) would one expect for a vehicle with a coil-sprung live rear axle setup? For the record I am aware of the debate concerning bent chassis possibly associated with the use of airbags.
Regards   

[Pog]

Hi UIZ733,

I have just had these fitted this week, to my 2013 Prado with standard suspension.

The answer is no.

I inflated to 25psi, measured height, and then deflated to <5 psi and had the same rear heights.

I towed the camper fully loaded camper and car, from Renmark to Adelaide with a a bit of a detour to drop off our dog, so about 400 kms, and couldn't be happier. The car and camper were level, and the ride was good.

[gronk]

Mine goes up approx 20mm from empty to approx 20psi in them..
When you inflate them, the bag has to expand somewhere  , so it goes up as well as sideways..

[DaveR]

The typical reason for installing these types of Air Bags, ( I have them in the back of the Troopy) is to reset the vehicle ride height when loaded with gear or a trailer on the back.
So for you, if the back of the tug sinks a bit with the Ct attached, inflate the bags till either ride height is achieved, or, max pressure reached.
I hope this makes sense.
To fill the air bags just for towing purposes only makes no sense to me.
As for the height adjustment, it depends on how they are fitted, each vehicle is different. For me, they just lift the rear end back to where it was before being loaded, does not jack the car up, this is due to the size of the bag having a limitation.

[AdrianLR]

I've had them in a Pajero and now Patrol. Measure the clearance between the top of the tyre and the arch empty, inflate to max (30psi generally) - you may notice a slight increase in clearance, attach the camper and reduce pressure until the clearance returns to the original. The airbags are to assist carrying the load, not to replace the springs. I normally tow with about 20psi another 15 with a full load it no camper and 5 empty.


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[UIZ733]

To fill the air bags just for towing purposes only makes no sense to me.

I was not intending to "fill the air bags" for towing. I was curious about the effect of inflating air bags and any alteration to ride height. My understanding (and I may be wrong) is that with a specific loading, the bags should be at a certain recommended pressure.

[gronk]

I was not intending to "fill the air bags" for towing. I was curious about the effect of inflating air bags and any alteration to ride height. My understanding (and I may be wrong) is that with a specific loading, the bags should be at a certain recommended pressure.

Yes, you are right, but to get the certain recommended pressure, you need to do it by trial and error, as all installations are different, and all loads are different..
Even though a load was say 150 kg towball weight ,you can,t say the air bags need 20 psi, as it all depends on how heavy the back of your 4 wd is, size of the coil springs, size of the air bag, etc etc..

I only run air in mine when towing, as I want it nice and soft when just running around unloaded..
But when towing, it might be 10 psi one trip and 20 psi another, depending on how much I load up the back of the 4wd ( short trip compared to a longer one )

[Beachman]

I’ve had airbags for about 3 years and I have no idea what pressure I run them at. Before the trip I pump them up and the back of the car rises about 5cms. Then after I hook the trailer up and finishing loading everything in the back, I then let air out until I get the desired height.

When I return home I let the majority of the air out again.

[UIZ733]

Thanks for the input.
Happy Christmas all.

[Landyline]

The point of these air bags is to increase the spring rate of your existing rear springs temporarily.

As described above you need to pump the air bags up before you apply the load. The bags work by expanding between the turns of the coil spring. Not by pushing between the bump stops.

Therefore if someone was to use them to gain ride height unloaded the ride would be rough as guts and you would lose a lot of wheel travel.

[whitey]

One thing to remember when you finish with whatever size load and air pressure to suit it, is that you have to have a minimum air pressure in them at all times... a deflated one will get a  typical " flat rubber tube" perished line in it and then it will be R/S , I keep about 5 psi ( when unladen  or normal carting stuff ) and the maximum I have had in it was 55 psi for a 850+ kg load, again that needs trial adjustments with road conditions etc. I have firestone, never an issue except for a "fitting"  air leak on a few occasions so it pays to keep an eye on them. 

[DaveR]

Argggghhhhhh!
Just went out to fill mine, ready for loading the Troopy for early morning CT departure, loading kit in and noticed she was a bit lop sided. 1 bag has a hole in it under the coil spring wrapping. Seems a small stone got in there on our Paddy's Flat Rd run last week and has made a pin hole.
May check out the fire stone option now, I have seen these air bags deployed many times to 300m of sea water or shallower, and come back in 1 piece.

[whitey]

That's a bummer... I try to keep an eye on mine a bit because another thing if they are under pressure I found when doing a sharp turn coming out of a driveway when in full lock there was a metal to metal squeak on a few occasions    : and after frantic inspections off and on a hoist I eventually traced it back to movement of the airbag ( still secured ) between the springs, it took ages to find and a puff of air and all fixed....just to keep in the back of the mind if an unknown rattle occurs on or off the dirt track

[UIZ733]

An update. I got the airbags and have fitted them. It was an easy task in the Ssangyong apart from inserting the hose into the top of the bag on the RH side being a bit fiddly. Early impressions are that the ride un-laden is significantly smoother. The ride was already very good, however it is now even better. I have not hooked the camper up yet consequently I cannot comment on what happens towing. Overall I am very pleased.
Regards

[whitey]

Once I learn how to get some pictures off my old phone and post them on here I will show my set up... I have made a plate / panel up and hooked up individual air gauges and valves to each bag where I can easily top up and exhaust the bags within a minute or 2, I have a " Hydro statically pressure tested" 9kg gas bottle which I converted to a air storage tank.. fitted snugly under my tray and I use that regularly to do tyre pressures and other various tasks but mainly for that air bag reason... I highly recommend one .....now just have to pull the finger out and mount the 150 psi pump next to the system so all I have to do then is replenish the tank with a flick of a switch

[Hewy54]

Fitted mine today on the cruiser. Without the bags, the KK used to drop the ride height by 60mm. With the bags at 30psi, the ride height has increased by 30mm, and the trailer now drops it by 35mm. Very happy with the result.

[Diesel Power]

To prevent premature failure of your beloved airbags, go to an upholsterer and get two sleeves made up that wraps around your spring with airbag inside. Get some elastic cord sewn in so you can tie off snug top and bottom. With a bit of extra material in the sleeve you can get some Velcro sewn in so they can be installed and removed easily.
The sleeves prevent stones wearing holes in airbags and protects springs from stone chips.
Regards
Angus.

[DaveR]

To prevent premature failure of your beloved airbags, go to an upholsterer and get two sleeves made up that wraps around your spring with airbag inside. Get some elastic cord sewn in so you can tie off snug top and bottom. With a bit of extra material in the sleeve you can get some Velcro sewn in so they can be installed and removed easily.
The sleeves prevent stones wearing holes in airbags and protects springs from stone chips.
Regards
Angus.

That is a must, mine are strashed thanks to a small stone, surprised they are not offered as an option when buying them.