Can I add to this? I have a Discovery 3 (06), have replaced the compressor but suspension warning light comes on whilst driving, with no apparant impact on handling. Vehicle will raise and lower up until light comes on. Have pulled fuse and left over night, vehicle remains level (checked with spirit level). Any ideas on what is causing the fault?
Best way to diagnose LR3 airleak
- Thread starter medicfernando
- Start date
GORM
Adventurer
I have not had to do myself but multiple posts on similar topics mention the need to update the LR3 software after replacing the compressor. If you replacement was a newer model or alternate brand you will need the software update.
Something else to check is the relay. You can really hope it is that simple because the relay is very inexpensive ($20-$30). It is recommended to replace the relay when you replace the compressor anyway.
There are numerous things that can cause the fault, not just a non working compressor so you may need someone with one of the advanced gap tool, faultmate, etc. to get the exact codes.
Something else to check is the relay. You can really hope it is that simple because the relay is very inexpensive ($20-$30). It is recommended to replace the relay when you replace the compressor anyway.
There are numerous things that can cause the fault, not just a non working compressor so you may need someone with one of the advanced gap tool, faultmate, etc. to get the exact codes.
ColoDisco
Explorer
Front, Rear and transfer valve blocks can leak internally and you will not hear or see the leak. As winter has taken a toll on our air suspensions I have seen several front cross link valve failures as well as transfer valve and compressor failures. The general rule is if it drops in the front only overnight it's the front cross link valve. Same goes for the rear. The transfer valve can be tested by removing the line from the compressor, holding the line vertically and putting a drop or two of soapy water on the line and checking for air bubbles, if you get air bubbles the is air leaking back to the compressor, this can cause extra wear on your compressor.
jymmiejamz
Adventurer
What are the fault codes? Or did you just replace the compressor because you have an air suspension warning lamp? If you switched to an AMK from Hitachi compressor a software update is required. If you don't update the software you will experience the same symptoms.
I've had poor luck with the soapy water test as well. I have a leak at the driver's front on mine and suspect the fitting at the top of the strut but don't see any bubbles. The valve block is new as a precaution but she still drops at that corner. I have more diagnotic work to do but it's not been enough of a problem to motivate me to get out in the rain and work on it yet.
jymmiejamz
Adventurer
If just one corner drops, it is likely the bag, not the valve block. I've also seen the line under the radiator leak, but I wouldn't say that is common.
Agreed - I suspect it's that corner. The strut is actually only about a year old so I find it unlikely the bag itself is leaking and suspect the fitting/plastic line yet I can't get any bubbles.
Since I have a bunch of extra tubing I was thinking I'd run a temporary line from the valve block to the strut and see if it still drops. If not, then I know it's line related and if yes, then the bag itself is bad.
Since I have a bunch of extra tubing I was thinking I'd run a temporary line from the valve block to the strut and see if it still drops. If not, then I know it's line related and if yes, then the bag itself is bad.
jymmiejamz
Adventurer
Is it an aftermarket strut? I've seen a ton of aftermarket struts leak within a year of installation.
DING DING DING!!!
Yes, it was a year old Arnott. I had just recieved a replacement Arnott (totally different design btw) for the other side that had broken and been replaced under warranty. I went ahead and stuck it in as a replacement for the side with the leak and it appears to have sorted it. Or at least slowed it significantly - I only did it Sunday and won't be back home until Friday to see if it's settled over the week. But it didn't settle overnight, so that's good enough for me.
jymmiejamz
Adventurer
Nice. FWIW I never even bother spraying with soapy water, its easy to figure out whats leaking down.
Going through my list of things to do on the truck before my upcoming trip and am dropping about 3/8'' overnight at the front EVENLY. I have soaped every connection and replaced the front valve block but am still losing the 3/8'', have the bumper off and examined the line from the transfer valve and it's not leaking.
Time to check transfer valve, or is that IMPOSSIBLE, given that I've replaced the front block with a new genuine front block?
Time to check transfer valve, or is that IMPOSSIBLE, given that I've replaced the front block with a new genuine front block?
If you can't find any bubbles with it in off-road height using the soapy water then the most likely culprits are the front valve block or a strut leaking internally. It sounds like you've done the 'pull the fuses' trick to isolate it to just the front but you'er still dropping both sides of the front - is that correct? If both fronts are dropping my guess is the valve block since it's the only common point between the two front struts. They run around $150 as I recall and are easy to change so at least there's that.
Honestly though if you're only loosing 3/8" overnight I wouldn't be too upset over that. If you found it on the bumpstops every morning that would be annoying, but it sounds like you have a very small leak that will be hard to find short of throwing parts at it.
Honestly though if you're only loosing 3/8" overnight I wouldn't be too upset over that. If you found it on the bumpstops every morning that would be annoying, but it sounds like you have a very small leak that will be hard to find short of throwing parts at it.
I have done the fuse pull and disconnected the battery in two,separate tests, lead me to replacing the front valve... Still having the same problem...
So that's the strange part, I've already replaced the front valve block and I'm still dropping overnight, at the same rate... You're probably right about ignoring it until it is more pronounced and easier to detect... I'm still going to replace the transfer valve and do a complete rebuild of my trusty old hitachi this weekend, still on original compressor and truck is going on six years old... I've replaced the desiccant once already about two years ago just as preventive maintenance.
Update, plugged the struts independently and have no leak down from the front struts after 8 hours of sitting in the garage. Used 6mm tubing and three way valve to isolate each side from the valve block.
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shedlock2000
Observer
I'd like to weigh in and ask for some advice on this also.
I have a 2006 LR3 with 156000miles on it. I have replaced all the bags with OEM. After pulling the fuse and disconnecting the battery, I lose about an inch overnight off all corners (roughly equally -- the back right is appears to lose slightly (probably 1/8 inch) more than the others).
I understand that isolating the system permits you to indicate front or rear valve block -- but what happens when all four corners go down equally over night? A friend has indicated that the air tanks occasionally leak, but mine pumps back up immediately first thing in the morning, so I am assuming that there is plenty of wind in the tank given that the compressor doesn't always kick in until about 2 minutes after start up. The compressor is running a bit more than I'd like and runs for 40 seconds and then switches off for a minute and a half or so -- then kicks back in again.
I've done the soapy water trick with no success and checked all the hoses by hand for sound and feel. Can the centre block lose air from the system if the front and rear valves are holding fine? Any suggestions?
I have a 2006 LR3 with 156000miles on it. I have replaced all the bags with OEM. After pulling the fuse and disconnecting the battery, I lose about an inch overnight off all corners (roughly equally -- the back right is appears to lose slightly (probably 1/8 inch) more than the others).
I understand that isolating the system permits you to indicate front or rear valve block -- but what happens when all four corners go down equally over night? A friend has indicated that the air tanks occasionally leak, but mine pumps back up immediately first thing in the morning, so I am assuming that there is plenty of wind in the tank given that the compressor doesn't always kick in until about 2 minutes after start up. The compressor is running a bit more than I'd like and runs for 40 seconds and then switches off for a minute and a half or so -- then kicks back in again.
I've done the soapy water trick with no success and checked all the hoses by hand for sound and feel. Can the centre block lose air from the system if the front and rear valves are holding fine? Any suggestions?