Hi Folks, I have been having problems with my EAS lately. When I turn the engine off and the air pump stops working the valve opens and dumps all the air out of the tank. But all the air bags stay pumped up. I have checked the valve block and it all looks good. Any suggestions would be appreciated.
Thanks, Alan

Is it dumping all the air or is it just the normal self levelling when you switch off and get out of the car?

Hi Gilbertd,
thanks for your reply. It is dumping it out of the little muffler. I have a gauge connected to the tank and it dumps all the air.
Thanks, Alan

That would suggest the diaphragm valve is leaking. Does it take longer than normal to fill the reservoir? When they split normally it doesn't build pressure as it all goes out the exhaust.

You can check to see if it is a pneumatic or electrical problem by pulling fuse 44 (pre-99) or fuse 29 (99 onwards) and seeing if it carries on dumping the air. If it does, it is the diaphragm valve, if it stops, you've got a weird electrical problem.

There's only two possible paths for tank air when the system is switched off:

1. NRV-1 should be holding tank pressure before it gets to the diaphragm valve.
2. The other route is via NRV-2 --> Inlet Valve --> Block gallery --> Exhaust Valve --> NRV-3 --> diaphragm.

Scenario 2 is very unlikely, so I would suspect NRV-1.

Hi Richard, Well I spent the day working on the Range Rover in the rain. At least the rain was warm, 33c at the moment, in Queensland Australia. I made up an air line with a tap and a pressure gauge and a non return valve and a schrader valve in the line from the compressor to the valve block. After a lot of testing I came up with the same as your suggestion, the diaphragm. So I removed the valve block and took it into the shed and looked carefully at the diaphragm. It did not look that bad, but it was a little loose in the recess. I then started reading the overhaul instructions for the valve block and I realized that the little cover plate is missing. I checked the 2 spare valve blocks and they are the same, no cover plates.So it looks I will be machining up a replacement cover. Only problem is I don't have one to copy so it will be a bit of a guess as to exact sizes go, but a rainy day working on the lathe will not be that bad. I thank you very much for your suggestion. I will let you know how I get on with it.
Regards, Alan

Hi Pete12345, I must have missed your post last night. Thank you very much for your diagnosis. That is exactly what I was hoping for some real directions to follow. I will check the non return valves first thing tomorrow morning, then I will check all the other valves.
Thank you very much, Alan

Also remember that NRV-2 is always open when there's tank pressure, so generally has the least wear on the tip & o-ring. Examine them all and put the best one in NRV-1 position.

Grab this document. It has nice diagrams of how the valve block works.

Also the diaphragm valve does not have a separate disc. It should be bonded to the rubber, so if yours doesn't rep0lace the diaphragm. Diaphragm valve picture

I think he is referring to the steel disc that sits inside the diaphragm, the one on the right here

Like this.....

Hi Gilbertd,

Thanks for your response to my private message earlier....somehow I've deleted it before reading it all 🤯
Not driven the car today so just gone out to it, on the bump stops, 20 seconds after starting it was up to standard profile. By morning it will be back to the bump stops.
Replaced all o rings in the valve block but didn't lubricate the diaphragm, could this be the problem of perhaps looking at this threadcould it be an NRV?

Boberto wrote:

Thanks for your response to my private message earlier....somehow I've deleted it before reading it all 🤯
Not driven the car today so just gone out to it, on the bump stops, 20 seconds after starting it was up to standard profile. By morning it will be back to the bump stops.

Fortunately my reply is still in my Inbox, so a quick copy and paste:
If it is dropping when parked you may have a leak somewhere. Once the engine is turned off, 2 hours after it was switched off and then every 6 hours the EAS timer wakes up and it self levels. It does that by lowering the other 3 corners to match the height of the lowest. So if one corner has a leak it will drop, the timer will wake things up and lower the other 3 to the same height. Then the iffy one continues to drop so the other 3 are lowered again until it is sitting on the bumpstops. However, if the car is parked on an uneven surface so the suspension on one corner is compressed, it can see this as being low and lower the other corners.

The way to stop the self levelling is to pull the fuse that supplies the EAS ECU. This is fuse 44 on a GEMS car (up to 98) or fuse 29 on a later Thor car (99 onwards). Both these are in the underbonnet fusebox. Without the self levelling, if you have a leak on one corner, that corner will have dropped while the other 3 will stay up.

Thank you.
I did forget to lubricate the diaphragm when I rebuilt the valve block, which by the way wasn't operating at all until I replaced all o rings and seals in the pump and air drier.

Should the diaphragm be lubricated or could it be a NRV?

I'll remove the fuse now and see what the morning brings.

When I do them I don't lubricate anything. Some guides tell you to assemble it dry while others say to use Vaseline or Silicone grease. The problem with putting any lube in there is that any dust from the dryer (and there always will be some after a while) will stick to it and cause it to gum up much sooner than it would normally.

Do the check first to see which corner drops when left with the fuse out.

Thanks Richard and Pete12345, lots of good information there. I am off to the shed to do battle with my valve blocks. I am hoping to get it fixed today as I have a hoist reserved at my mates workshop to replace the ball joints, panhard rod bushes, trailing arm bushes and steering damper etc. At worst I can pump it up with the emergency valves and get back to the valve block later.
Thanks very much gents, regards, Alan

Hi Folks, Well I pulled the NRV out and I found that the one that goes in the opposite way to the other 2 was broken, the little pin was broken. I am not sure if I broke it or it just broke on its own accord. But the air suspension just started playing up on the way home from a trip. So I went looking for another valve block. I found one in a big box of parts I got from a wrecker. I just put it on my P38 and tested it, and it worked perfect. But it is of unknown quality, so I will make a new NRV and reassemble my original valve block and then try it on my vehicle. So I had time find all the tools I think I will need to replace all the suspension parts and load them in to my P38, so I am ready to go in the morning. Thanks for all your help, and I will keep you informed about any progress.
Regards,
Alan

If you can make NRV’s, you probably have a market for them here.

Hi Folks, I got my Range Rover up on the hoist and removed the front arms, and pushed the bushes out. Then I looked at pressing the new ones in and I realized I would need some special tools. So I want home to the lathe and spent the rest of the day machining up the special tools I need to finish the front arms. So I haven't had time to get back to the EAS. Harv I will make a NRV for my valve block and see how much of a PITA it is. I know it will be fiddly, being so small but doable. Then I will think about making more. I have recently retired and was looking forward to working on my vintage bikes. About 74 of them. So far I have not touched one of them, but it hasn't been 12 months since I retired.
Regards, Alan

If you do manage to make good NRV's, there could be lots of people interested in buying them.

I got a quote from Dunlop Systems back in 2021 for them, but decided not to invest £500 plus VAT !!

Quote: "The part number you require is E 3 1133 00 36 @ £10.30 each. There would be an MOQ of 50 pieces on this"

Pete

if we could get 10 people I'd chip in £50 - but I bet it has gone up :(

Gilbertd wrote:

When I do them I don't lubricate anything. Some guides tell you to assemble it dry while others say to use Vaseline or Silicone grease. The problem with putting any lube in there is that any dust from the dryer (and there always will be some after a while) will stick to it and cause it to gum up much sooner than it would normally.

Do the check first to see which corner drops when left with the fuse out.