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1995-2002 Range Rover P38A
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Discussion Starter #1
Hi folks,
As the title says...when left parked in 'normal' height, after an hour or two, the car is sitting at 'offroad' height. It drops down to 'normal' when fired up and driving, so not a massive problem, just weird! Any ideas as to why, and what to do to stop it?
The 'self-levelling' function seems to be switched off, which is fine, but if it isn't, where do I find it in Nanocom?
Cheers!
Iain
 

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Hi there, it suggests there is a kind of general leak in the eas valve block. When it is so quick, you probably can hear it with a stethoscope on the valve block ( units). Note there is a delay relay that shoold perform corrections when left parking. Some people exchange the delay relay with a normal one (or when the time part of the relay does not work any more). Then there will be no corrections when left parking
yours simon janssen netherlands.
 

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1995-2002 Range Rover P38A
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Discussion Starter #3
Looks like a valve block rebuild is needed...pissing with rain, so not today! :)
 

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Okay, rain went off, so I whipped out the valve block after listening to it leaking through the exhaust valve, after I took off the silencer. That's where the air disappears overnight! As a temporary fix, I swapped the one non-return valve that sits 'nose down' with one of the other 'paired' ones. No more leak...:) Also, thanks Simon, swapped the Timer Relay for a four-pin generic, it doesn't click like crazy when I lock it, now. See if it stays at 'normal' height overnight...and has air in the morning! Valve block rebuild kit ordered...
 

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Don't forget that with the timer relay swapped you won't be able to connect to the system with any diagnostics, so make sure you keep the timer relay for then.
 

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1995-2002 Range Rover P38A
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I have the same issue on the rears; sometimes it raises up and sometimes not. It's got to be one of the NRVs in the valve block... right? Tha'ts the only path from the tank to the air springs.

I recently rebuilt it but I guess one or more of those little valves are not seating correcty. Would it more likely be the O-ring around the valve or the little valve with its spring? I don't know if I can be bothered dismantling it again, right now.

Tom
 

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1995-2002 Range Rover P38A
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Discussion Starter #7
Don't forget that with the timer relay swapped you won't be able to connect to the system with any diagnostics, so make sure you keep the timer relay for then.
Yes, thanks, mate, got it in the glove box :)
 

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Mine does same where rears rise up when parked (my auto levelling is also disabled when ignition off).

Not checked valve block yet, but I suspect weak NRV2 spring and bad seal on Inlet valve plunger. The valve plungers have small rubber inserts that tend to get a dimple in them over time. Apparently they can be carefully pulled out with a toothpick and inverted so the face is smooth again.

As OP says, not a great problem but will be looking at my spare valve block. I already refurbished it a while back, but didn't check the plungers. Maybe it's time.
 

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After reading up on this, it seems that if it was the inlet valve, all four corners would raise up. With mine, only the rears raise up, and not always. What is there in the valve block that could cause this? I'm looking at the EAS valve block diagram and can't see how one of the NRVs could cause this.

Thanks
 

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For any bag to inflate, there need to be at least 2 valves leaking (the one for that bag and either the inlet or the exhaust and NRV3). For all bags to inflate, 5 valves need to be leaking, which is unlikely. If you're still using the timer relay, my guess would be NRV1 is leaking and when the EAS tries to lower a corner, it is actually adding air from the tank. Also note that infalting or deflating one bag will have an effect on the entire axle, so it's hard to determine if the problem is just one corner or both (unless the difference is large).
Filip
 

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Thanks Escape. I've been driving with the original EAS timer relay in. I just took it out and put the regular four pin relay back in. I'll watch it for a while and report the results.

Tom
 

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I'm still leaking UP on the rears overnight, on both sides with a generic four-pin relay in.

Should the mating face where the NRVs sit in the valve block be sanded smoothly, or is it the springs that go weak over time? I've got a spare valve block that looks pretty clean so I'm not too worried about being able to fix it. I still don't think I'm any wiser on exactly why it happens though.

Tom
 

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As above, the NRV valve on its own cannot cause this. The valves for the rear bags (one or both) also need to leak to allow air into those bags. A valveblock rebuild should solve all.

Filip
 

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Have recently done it. Oh well. As mentioned I have a nice clean looking valve block to rebuild and put in - again.
Still thinking about tapping threads into the air hose connections and installing threaded fittings - just for fun, and to see if it can be done - anyone done that?

Tom
 

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My compressor just died again (my fault) so I removed it and set the system to manual while I wait for another rebuild kit to come. I think what got me confused is both sides of the rear lifting up overnight when probably only one side has the fault. Strange that another P38 I can see from my office window has the same fault.

Does anyone know if the mating face of the NRVs inside the valve block need to be polished smooth with very fine wet and dry paper or steel wool?

I'm theorising that if I pull that valve block out and attach a bike pump to the line that goes to the compressor tank, pump up the pressure to 150 - 170 psi, I should be able to find the leak if I immerse the block in water, or just soap it all up. I'm going to strip that valve block anyway as I have two spares.

Thanks - Tom
 

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You can check the valve block, but it's a bit more complicated than just putting pressure into the compressor line. For starters, you'll need to bridge the 8mm lines to the dryer for air to get to the tank. Easier to just put pressure in the line to the tank. But that will only check NRV1 (for the tank) and the inlet valve. To check all valves, you need to check each spring line separately. This can be done for example by connecting a reservoir, getting it up to pressure and then checking if it drops over time. Not complicated, but time consuming. See diagram:
286551


Also, don't immerse the entire valveblock, the solenoids might not like that.
 

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Escape

I missed your post with this circuit. Thanks for that I'm working on the valve block now; this diagram makes it easy to understand.

I'll report back

Tom
 
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