Thread: Polyair Suggested Pressures

Trial & error is your friend. Depends on the spring rate not lift per se, loads carried etc.

I generally run mine at the minimum 5 psi around town when empty, 10 psi on the open road if loaded up, & 18 psi when towing.

Regards
Max P

IMHO air assist springs air pressure should be set to what it needs to be to reatain the vehicles correct ride height. (kudos to the old man teaching me this in his kingswood)

As Im looking to air springs for Big Red my line of thought has been thus...

before fitting.

Load up the vehicle to get it nice and stable. for me the rear suspension of big red when empty is too fidgity but adding 80-100kg settles this nicely, not a problem for me tool box, pram and alex's change bag sorts it nicely and these are always on board

tie a piece of string off of the tow hitch so that it just touches the ground (flat level ground please), wrap it up around the hitch and leave it there.

fit your air springs and put the inflator sockets near the tow hitch

unwind the piece of string and let it hang, inflate the airbags to minimum reccomended pressure in theory the string shouldnt move clear of the ground by much.

rewind the string

Now when you load up the vehicle or hitch up all you do is inflate the airbags till the string just clears the ground and you have the correct pressure in the bags.

of course if you get really really gucchi about it you could fit a compressor tank and auto levelers to control the bags.

Dad had a slightly differnet method, he had a cut down spanner he slotted over the inflator (inside the mud guard) when the airbag lifted the suspension enough to clear the wheel the spanner would swing free then hed go do the same on the other side.

http://www.4wdworld.com.au/products/polyair/index.htm

GENERAL MAINTENANCE TIPS: After fitting kits and/or extension leads, inflate air bags to 175 KPA / 25 lbs and test for air leaks by applying a liquid soapy solution to all valve cores, fittings and connections.

Caution - Do not inflate air springs while vehicle is on frame hoist. Vehicle must be standing on its wheels before bags are inflated.

• Maintain at least 35 KPA / 5 PSI of air pressure in the Air Lift Bags to prevent chaffing.
• Inflate your Air Bags before loading your vehicle to maximum pressure indicated on fitting instructions.
• Do not attempt to raise a loaded vehicle by inflating Air Bags. If loaded, jack up body until level, then inflate.
• It is recommended that tyre pressure be increased by 14 KPA (2 lbs) above normal for each 45 kg / 100 lbs total overload on the axle.
• POLYAIR SPRINGS recommends that the kits be used to support loads which are within the vehicle manufacturer's rated GVW.

Recommended standard Air Lift Bag pressures are included in installation instructions and vary from kit to kit. Typical values are min 35 KPA / 5 lbs, max 175 KPA / 25 lbs.

In other words inflate first, load and then deflate to restore the preloaded ride height.

Mind you it is a rule that I have broken.