Thread: Onboard Compressor - suspension backup and for tyres, etc

that'll work but your tools are going to be limited to dusters and inflators. The ARB compressors can reach 150PSI (most of them these days can) But they do not like starting against more than about 30 PSI so I would consider fitting an electrically triggered check/unloader valve on the AUX compressor with decent thickness hose to give the compressor a second to get up to speed before the pressure comes on against it.

I have also fitted a compressor behind the left headlight (had to make a bracket or shelf to mount it there). The compressor is an ARB CMK12 or whatever the model number is; basically the one they still offer with the blue aluminum mount/band on it. Duty cycle on the ARB compressor should be fine for what you are asking, so are some of the other better compressors.

The only issue with this compressor is it has a shut off switch which typically stops at around + or - 5 PSI at 95PSI. The air suspension operates in the front at about 116-145 PSI and the rear at 75-116 PSI.

BTW I have not noticed the difficulties at running the compressor with tires already inflated over 30PSI; but I usually turn on the compressor first then attach to the tires.

Viair make compressor with higher pressures such as 120 PSI 150 PSI and even one for 200 PSI, which mounts to their own air tank and is weather etc proofish - cannot remember the spec, exactly as to the weather proofing.

Search around I think I read a forum thread, perhaps here or on the UK site where others had fitted a second air tank on the opposite side of the rig and connected the two. Not sure exactly if there wer any issues but my guess is that it is doable. Might just be wise to have two seperate and independant setups for redundecy case.

Another option is to just have a spare compressor, perhaps even portable. Which I may use and or do. You wont likely have to mess about in the bush much if you use an EAS setup like Green Oval Experience is putting out since all you will need to do is take the airhose and connect it to the inflator valve for the air spring or springs that are low. BTW need to pull the fuse in the engine compartment so that the system does not self lower if it wants to. i believe its fuse 26E.

I have installed my own air inflation kit on my rig, after a bad bump stops event. Basically some T-Pieces in brass, some airline and a few mounting points. A PIA job, but done none the less and each spriong can be inflated independantly. Mind you with the ARB compressor this amounts to something similar to the normal drive height of stock variety (not normal height with rods installed).

the next solution, which I do not have experience with but have been told about by a LR tech is that the D4 aircompressor can be placed in the D3, with only minor mods. Apparantly a straight bolt on but the hose routing is slightly different, I think it has to do with shortening an air hose. But it did not sound dificult. Also have heard that these compressors are much stronger and a bit bigger also and do not go out like they do on the D3.

Anyway that's what i can help with. Good luck with it.

Cheers

g;day all;, have read about ' endless air' in the 4wd magazines. they are supposed to run max 200 psi( with motor running). they are a converted air conditioner pump, run off the engine belts.......great idea but space in engine bay restricted. have a look into it anyway, you might find it will suit you. cheers.

MAgsy , you obviously have never seen inside the TDV6 engine bay !!!!You wont be fitting any more drives on that setup !
I wonder what these people who think they can fit a tank do with the fuel tank thats allready there ? The tank would be that small its useless !!

Based on “Blknight.aus” input (thanks) I have changed the design slightly in that I will put another one way valve and a 3/2 way valve on the output of the compressor. Wiring the 3/2 way valve in parallel with the compressor will mean that the line will vent to atmosphere every time the compressor stops – so no head of air to start against next time it starts. When it restarts the 3/2 way valve closes and the line begins to pressurise – once the line pressure is above the reservoir pressure the one way valve will open and charge the system.

A little more complex than I had hoped but I enjoy these little projects – keeps me sane. Rev 1 of the design attached..

Just read this thread :

http://www.disco3.co.uk/forum/topic65683.html?highlight=%2Bair+%2Bspring+%2Brebu ild

One thing I have not thought of is the water removal silica balls that the landy compressor has - does the ARB unit have the same feature? Read their website but can not find any mention of it.

I may need to go to Rev 2 on the design?? This is getting complicated

I do like the idea and been toying with the thought of doing it also. Keep in mind if there is another type of failure, say electrical or a valve block or etc it could allow the D3 vent air from the air springs, even with this system. You may still wish to consider some kind of EAS kit. I know this system is great for a portion od redundancy and Tools and the like. Just a thought.

keep up the good work and thanks for sharing.

Originally Posted by HarryO

I may need to go to Rev 2 on the design?? This is getting complicated

Actually by the time you get it all working, you will have sympathy for the Land Rover guys who did the system up first time.

Consider that you have a family to feed and the assignment is to design an air suspension system that has never been tried before and you know it is going be to mass produced a few thousand times before effective field testing is done. You may as well update your resume.

Yes, the air dryer thing matters, at least where the temperature goes below freezing. Where it does not, well you hope the air tank has a non rust coating inside and the other parts are all plastic or rubber.

What you are doing will work fine but along with the check valve, I would have a full on off valve between the two tanks and keep it shut most of the time. Use the ARB air source for tyres etc but you will at least have a good and simple alternate when your LR air compressor quits - which it will. When that happens, I would get the truck up to desired height and then not change height unless I really had to and get the LR compressor back in service as soon as practical. The less moisture in the system, the better.

The D3 tank on the right side is the elegant and safe way to carry extra air. My complements.

No one but LR has an air dryer as a part of their standard air compressor design - well yes on Mercedes etc but not the portables. The problem is how to dry the dryer. LR solves that by exhausting the compressed dry air back thru the desiccant. For the portables, there is no exhaust air - it is in a tyre. Ultimately for all its problems, you will come to the conclusion the LR design is pretty good.

My view is the only real mistake they made was running the air storage system at +200 psig. If they had put the second tank in, kept storage pressures and hence the compressor working pressure to about 150 psig, we would have had a near perfect system. No one yet, (well not Hitachi anyway), can make a cheap single stage oil free compressor that will run for any length of time in any climate at +200 psig.