Thread: How D4 Suspension handling on corrugation and Simpson?

Ivan make a very good point.
An airbag that is inflated to a height in extremely hot conditions will loose some of the air content overnite due to it cooling out.Same goes for air stored in the airtank.
Has anybody ever considered fitting a second airtank to the system????
Andrew

Originally Posted by LandyAndy

Ivan make a very good point.
An airbag that is inflated to a height in extremely hot conditions will loose some of the air content overnite due to it cooling out.Same goes for air stored in the airtank.
Has anybody ever considered fitting a second airtank to the system????
Andrew

The EAS would fault with a "Normal Height Only" message and fault code for "reservoir filling too slowly" if there was a 2nd tank fitted.

Same as others,done heaps of k's on corrugations,Simpson across and back,Flinders ranges,etc.
In fact the corrugations on the road around Finke and Mt Dare,were, at the time the worst i have ever driven on.
On the roads around the farm in SW Queensland,also no worries at all.

As others have said,the big issue is the vehicle is so comfortable it is VERY easy to drive too fast,which flogs the suspension and will badly chip the rear tyres,no matter what brand are fitted.

A good set of LT rated tyres are also very important,heaps of threads on here about tyres.

Originally Posted by Grentarc

The EAS would fault with a "Normal Height Only" message and fault code for "reservoir filling too slowly" if there was a 2nd tank fitted.

Why???
Once they are full they are full,you have the extra capacity,doesnt mean you are using twice as much.
Andrew

Originally Posted by LandyAndy

Why???
Once they are full they are full,you have the extra capacity,doesnt mean you are using twice as much.
Andrew

You have to fill them in the first place. This is when it will cause the fault, and any time you raise the suspension from access to off road, as it will use more reservoir air than normal (stock reservoir doesn't have enough air to go from access to off road all by itself - but reservoir air is used before compressor starts helping), meaning the compressor will have to replenish more air than it is expecting.

I had the same problem on a visit to Fraser Island. On my return it continued and found the compressor wanting. I replaced the compressor and have never had a problem since. I agree with a lot of the other comments about corrugations. A D4/3 is the best vehicle to drive on them. To u oat drivers are just jealous. They have to spend big money to upgrade to try and achieve something similar to the ride in a Landy.

Originally Posted by Grentarc

... meaning the compressor will have to replenish more air than it is expecting.

With respect to the "Normal Height Only" message and fault code for "reservoir filling too slowly"

Are you saying that fault is raised only by the compressor running longer than a fixed time period regardless of what the tank pressure starts off at. That is, is the logic - if I run for X seconds and I have not yet reached y Kpa set point then I'm slow - so raise an alarm.

Or, is the alarm raised by a little more complex logic, such as - I'm at x Kpa now. I need to get to y Kpa (pressure set point) therefore I need to run for Y seconds to achieve this. If I run for more than Y seconds and I'm not yet at pressure set point then I'm slow - so raise an alarm.

The 2 logic cases are slightly different.

I get that error occasionally but only when driving away in the mornings after my system has de-pressurised over night a/c I have small but intermittent leak in my emergency air up gear. I have never been able to induce the alarm by cycling the suspension a few times from access to off road height via the buttons in the cab

I am trying to work out if the alarm means I have a problem with my compressor or the alarm would always arise when pressurising from an empty tank regardless of the condition of the compressor.

Another area people overlook is the 4x4 info screen. If you have various errors like suspension problems they often show up on that screen and point to the wheel concerned. May save a lot of time diagnosing things if you haven't got a scan tool.