Thread: EAS Overhaul and GOE Emergency Air Installation

Originally Posted by Ferret

If you install it, ensure you have an air compressor capable of inflating the air bags if you ever need to use it. Most 'garden variety' compressors can inflate the rear bags to lift the the rear fairly easily but will really struggle to inflate the front bags to to lift the front to any degree.

PSI they are trying to pump to?

Originally Posted by gavinwibrow

PSI they are trying to pump to?

Good question. I'm going to fit my kit (was bought for the D3 but never got around to installing, glad now, as it will go into the D4) and thought I'd read you needed a compressor with a bit of grunt. I kept the ARB single from the D3 and have been thinking is it good enough for the air up kit. Or do I need to hand over the first born for a twin or something else?

Also, why are the fronts more of a problem? I thought the rear was heavier and IIRC (happy to be corrected here) the rears are a bigger unit?

Cheers David.

Just remember these kits are not designed to be able to pump the car back up to extended or super extended heights, tyre style air compressors just do not have the pressure to do this - however they do have the pressure to get the car up off the bump stops and to a height that is good enough to get the car going and at a height that is good enough to get over offroad terrain if the driver is careful.

A good 150psi air compressor used for tyre inflation is good enough for this and that is what the inflation kit is deigned for.

Garry

Originally Posted by Dagilmo

Also, why are the fronts more of a problem? I thought the rear was heavier and IIRC (happy to be corrected here) the rears are a bigger unit?

The front is heavier unless the rear is heavily loaded. As an indication, the rear valve block has a restriction whereas the front doesn't, trying to equalise the rate of raising.

Originally Posted by Graeme

The front is heavier unless the rear is heavily loaded. As an indication, the rear valve block has a restriction whereas the front doesn't, trying to equalise the rate of raising.

I’d like to get one on scales. This doesn’t make sense to me given the tyre pressure figures standard of 33psi and 36psi front to rear. I appreciate there is an engine there but .....

Originally Posted by Graeme

The front is heavier unless the rear is heavily loaded. As an indication, the rear valve block has a restriction whereas the front doesn't, trying to equalise the rate of raising.

I understand that this is so that the front always lowers first. Next time it's on the bump stops at access height, note that when you raise it that the rear always lifts first, then the front, the reverse when dropping back down. To my knowledge that is a requirement for EAS equipped cars so that the headlights are always kept as low as possible. I think the weight distribution is pretty even too. Would be interesting to know what psi the eas runs the struts at

From the WSM...
Pressures:
Normal - Front 800 to 1000 kPa (8.0 to 10.0 bar) (116.0 to 145.0 lbf/in²)
Normal - 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)


Also from the WSM...
The front and rear axle valve blocks are similar in their design and construction and control the air supply and distribution to the front or rear pairs of air spring damper modules respectively. The difference between the two valves is the connections from the valve block to the left and right hand air spring damper modules and the valve size. It is important that the correct valve block is fitted to the correct axle. Fitting the incorrect valve block will not stop the air suspension system from functioning but will result in slow raise and lower times and uneven raising and lowering between the front and rear axles.

Originally Posted by Graeme

Normal - Front 800 to 1000 kPa (8.0 to 10.0 bar) (116.0 to 145.0 lbf/in²)
Normal - Rear 500 to 800 kPa (5.0 to 8.0 bar) (72.5 to 116.0 lbf/in²)

Aligns with my experience from a few days ago with a mates D4.

Tyre compressor easily raised the rear to about on road height without the compressor relief valve blowing. Measured pressure in bag ~85psi.

Tyre compressor relief valve blowing at ~90 psi on the front bags - just off the bump stops but quite a bit lower than access height. This was after jacking the front up to reduce weight on the bags.

Tyre compressor was a el chepo 'Thumper' from 4WD Super Centre. Another mate had an expensive ARB compressor. It performed slightly worse, not being able to reach 90 psi the Thumper achieved.