1.How often and how long should the compressor run? Is it normal to run for about 1 min every startup with about 4 hours between startup?

2.Also, when going from normal ride height to the off road suspension height, how much does the front and back raise in inches?

Thanks!

 

The reason I ask is because Im thinking about going over to the arnott front struts as I may a leak in the right front. I want to make sure that the measurements will be the same as factory.

Anyone have these? Thoughts?

 

This is a link to a pdf you can download. It tells you how the system operates and includes a colour cut thru of the air compressor.

www.disco3.co.uk/gallery/albums/userpics/15405/Land%20Rover%20factory%20D3%20air%20suspension%20d escription.pdf


You will not have to worry about vehicle height as the height is set within the computers via signal from the individual wheel height sensors. To change those numbers, you need a Faultmate or the like. In other words, you can make the height anything you like sort of via the Faultmate; the LR heights are what LR regards as roadworthy.

I would say you have a leak somewhere - my system which is fairly tight may run for about 30 seconds in the morning at start up perhaps every second day; a minute after a four hour shutdown suggests a leak.

Per the link below, you can pull fuse 26 in the engine compartment in the evening after you shut down for the day. Pulling the fuse shuts all programmed venting so in the morning if you see one or more corners down, you know you probably have a leak related to that corners air system components.

DISCO3.CO.UK Photo Gallery - LR3 Air Suspension fuse 35P ECU Manual Shut Off Switch

This is a nice line/block drawing.
http://www.disco3.co.uk/gallery/albu...rt%20names.doc

 

My compressor runs every morning for under a minute - can't recall if it does the same after a period of hours. I believe it's just topping off the pressure reservoir "in case".

Can't recall the height change from normal to off road off hand - something like an inch or two. Certainly not six!

 

Yea I have a leak. My LR tech cant find it though. We replaced the crosslink valve twice because it was showing error code there. They could not find a leak in the strut, but I think it is the strut. Soapy water is not working to test though. Are there any other ways to test?

 

While rare, an air line can develop a leak due to rubbing on something.

If you pull the F26E fuse, among other things, that depowers the cross link valves. If a corner goes down, that pretty much says the leak is in the respective air spring or the air line between the air spring and the cross link valve to which the airline is attached.

You would have already soaped the two fittings so the easy source of the leak has no doubt been eliminated.

 

+1 on the chafing - I've seen mentions on the UK Discovery boards of apparently okay looking air lines which have leaks due to rub through on the chassis which took a while to isolate. As BBYER suggested, do the no fuse test...

 

Pulled the F26 fuse, the just the right side of the vehicle lowers overnight, front and back.

 

This sounds unlikely, but I wonder if you have leaks in both the front and rear air springs on the right side? Both headlights can burn out at the same time, or at least close enough that it seems that way - perhaps one air spring has been leaking for quite a while and then the other has just started, something like that.

I was looking at the block diagram per the link below and there is nothing common to the front and rear that would also not let the air out of the other side was well.

What I am saying is that I am confident that both your front and rear block valves are OK. Both would have to be leaking on the right side and that while also unlikely is possible but given that you have installed at least one new one, then having both block valves leaking is unlikely. I have heard of the air dryer beads deteriorating, making dust and the block valve orifices plugging or not allowing shut off, but then the other side would most likely give problems as well.

Short of switching the left and right side air springs one at a time, there is no real practical way of figuring this out - and I would not regard switching the air bags side for side as practical by the way.

About all I can think of might be to purchase an M10 x 1 threaded cap or perhaps a collar and plug may be better, (and maybe even two of them). Then remove the Voss connector from the top of the front right air spring and cap the air line off.

(M10 x 1 is the thread of the Voss connector threading into the top of the air spring.) Do this with the system pumped back up so the rear right is "full" and then jack the front such that the 3 is again level as if the front tyre and air spring were as normal and let things sit overnight.

Either the rear right will be low in the morning or not.

If it is, and I expect it will be, then there must be a leak in the rear spring or the air lines between the rear spring and the capped off front air line, but most likely the rear air spring.

If the rear is OK, and I doubt it will be, then your problem is somehow front related and probably the front air spring - but that would be too easy.

Given that the rear probably sank overnight, I would then hook the front air spring back up and disconnect the rear and see what happens overnight.

In theory, the front should certainly go down again. In that case, then I would disconnect at the block valve where the right front air line enters the block valve and cap that entry point off.

I would also get a Schrader Valve and suitable 6mm air line fittings to hook to the air line going to the front air spring. I would then fill the front air spring from an external source to at least 100 psig and see if the air spring holds air a couple of hours later. If still OK in a couple of hours, then leave it overnight. Probably cooling will lower the pressure so a few psig I would not get excited about, but more than ten psi, I would start to think the air spring has a leak - good news at this stage of frustration I guess. I would also be doing the same with the rear air spring.

In summary, the air lines to the air springs are nominal 6mm tubing, not 1/4" and hence most temporary fittings that may be required are 6 mm as well. The Voss thread on the Voss connector going into the top of an air spring is M6 x 1. You can also purchase brass fittings to get from 1/4" NPT which the Schrader valve will probably be to the 6mm air line or M10 x 1 thread with some difficulty at a Mercedes or Volvo truck or machinery outlet.

http://www.disco3.co.uk/gallery/albu...rt%20names.doc


DISCO3.CO.UK Photo Gallery - FASKIT Air Suspension Installation/FASKIT on end view

 

FYI the valve block can leak back into the system even with the fuse pulled. The main lines between the compressor and the rear and front valve blocks release pressure after the compressor shuts off so if the valve blocks are not sealing completely individual corners can drop.

The valve blocks do start to leak over time. my front use to drop overnight and on one side more then the other even with the fuse out. new valve block fixed it.