Thread: twin air tank D4.

As below, the air springs tend to operate under 150 psig as they are not much different from the air springs on highway tractor trailer units whose air brake supply systems tend to run at about 120 to 130 psig.

This is why I think LR should have added a second air tank and reduced the pressure that their compressor runs at; the higher pressure was just to cram more air into a smaller tank volume and not because the air springs required it.

Spring/damper modules, (the four air springs, one on each corner):
Type Guided air spring surrounding twin tube damper, (shock absorber).

Air Spring Normal Operating Pressures:

Front: 800 to 1000 kPa (8.0 to 10.0 bar) (116.0 to 145.0 lbf/in²)

Rear: 500 to 800 kPa (5.0 to 8.0 bar) (72.5 to 116.0 lbf/in²)

Burst pressure: 3500 kPa (35 bar) (507.5 lbf/in²)

Maximum spring pressure - Full bump at gross vehicle weight, approximately 2700 kPa (27 bar) (391.5 lbf/in²)

Air compressor:

Supplied with air drier, electrically switched, pilot operated exhaust valve and double temperature sensors; controlled by ECU. Maximum pressure 1680 kPa (16.8 bar) (243.6 lbf/in²)

Air reservoir:

Working pressure 1750 kPa (17.5 bar) (253.75 lbf/in²) Maximum operating pressure 2300 kPa (23 bar) (333.5 lbf/in²)
Volume 9 litres (0.31 cu.ft)

I agree Pete a second tank would be a much better option but for most people it is not an easy one. Finding a suitable pump or pumps that will make the most of the present system with minor plumbing alterations is for most the only realistic option at this stage.

Maybe a smart operator with an eye on making a profit could look at putting together a second tank kit with the required plumbing that was a relatively easy install?

I'd seriously look at that option if it was offered at a reasonable price.

cheers,
Terry

Originally Posted by TerryO

I agree Pete a second tank would be a much better option but for most people it is not an easy one. Finding a suitable pump or pumps that will make the most of the present system with minor plumbing alterations is for most the only realistic option at this stage.

Maybe a smart operator with an eye on making a profit could look at putting together a second tank kit with the required plumbing that was a relatively easy install?

I'd seriously look at that option if it was offered at a reasonable price. cheers, Terry

Freight is always the cost problem, but a couple of brackets that would strap/bolt onto the ends of an OEM air tank obtained from a wrecked 3 or Sport would probably cost wise work out pretty good. It could be a practical mod then as only the brackets would be shipped and one could find an air tank locally. I think there are already suitably placed holes or bolts in the right side frame rails that could be used to attach the brackets to.

The hardest part would then be running a piece of the 6mm nylon air line across the underside of the 3 without the airline melting from the exhaust system heat.