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1995-2002 Range Rover P38A
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Discussion Starter #1
Greetings from Melbourne, Australia

Over the last few weeks I've been having the random EAS height rise issue which seems to clear itself pretty quickly. There's plenty about this on this site which seems to suggest a failing driver pack.

Several days ago the system seemed to take too long to rise up; just after that it went into a hard EAS fault; all the lights on the EAS indicator on and a 'slow: 55 kph' message. I'm not too worried about the random rising and the EAS fault; it's that it seems to have developed a leak somewhere. I will deal with the random rising and fault message in time, or perhaps they're connected to the leak which is my concern.

1) I bought air fittings and some hose so I can inflate the system manually with my bike foot pump. It works beautifully; all four corners are now sitting nice and high with 60 psi in each bag and not deflating so I know the leak is not in the airbags or lines.

2) I bought a few more fittings so I can attach a line to the compressor then attach the bike pump's gauge to that line to check the pressure. It's very healthy at over 220 psi; since I rebuilt the compressor recently I don't think the leak would have been there. Anyway I wanted to check the pump's output.

3) The issue is that, with the fault code cleared, or if I manually run the compressor, the system won't pressurise and raise the car; there's a leak. I've sprayed soapy water over the EAS valve block and all the air lines coming out of it but can't see any bubbles. I rebuilt that block a couple of years ago anyway so I think it's good.

Now I'm out of ideas. I'll deal with the electrical faults in time, but since the compressor runs and it is healthy, then there must be a leak somewhere.

Any ideas would, as always, be much appreciated.

Tom
 

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1995-2002 Range Rover P38A
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First thing I would do is replace the diaphragm, clean all connections in the eas, it sound as though it is the valve block, either diaphragm or nrv gone bad
 

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Discussion Starter #3
Thanks Chris.

Ah, yes. That's logical. It's been two years since I rebuilt it; perhaps it's time to rebuild it again. I remember that even small leaks from that little box would shut the system down.

1) If it's the diaphragm or non return valve, I should be able to see it escaping from somewhere around the valve block - maybe the exhaust silencer. I will have a better look. It must be going somewhere.

2) When you say non return valve, replacing the o-rings in those three valves should do the trick, right?

3) EAS connections: there's the ECU under the left hand seat; timer under the side of that seat and the connections going into the EAS under the bonnet. Are there any more connectors I should clean?

Many thanks

Tom
 

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1995-2002 Range Rover P38A
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Discussion Starter #4
Found the leak!

Pissing out air around the exhaust silencer; must be the diaphragm. Don't know why it wasn't bubbling out around there before. Perhaps I didn't spray on that piece enough. THANKS for your help.
 

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Did you change the decadence or drier when you rebuilt the block, it can leave a dust over everything otherwise which can cause problems
 

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woa there Atticus... just because you are holding air at one height does not mean you have no leaks. Bags usually form cracks and leak between the lower end of normal height and upper end of highway mode. As the suspension articulates the cracks open up and leak air. The compressor has to work overtime to keep up with the leaks and trying to keep the reservoir full. When the system is seeing no measurable increase in tank pressure it shut down the system to prevent further damage, thus the hard fault and speed warning.

Concentrate on your front bags. Rear bags will outlast front two to one and rarely fail. Let some air out and saturate in soapy water. repeat down to access height. When see cracks pay very close attention.
 

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But he's already said it's coming out the exhaust silencer so it's a leaking diaphragm valve. My experience is that rear air springs (air bags are the things that blow up in your face if you hit something) that leak first. Every car I've owned and worked on has needed new rears at least a couple of years before the fronts. One car I bought had both rears down to the canvas and leaking but the fronts lasted another 3 years before they started to leak.
 

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Discussion Starter #8
Thanks Chris, Richard and Toad

Toad, what's the hound? I'm thinking English Springer Spaniel crossed with...

1) I know I have a leak from the valve block; lots of bubbles around the exhaust silencer; this doesn't mean I also don't have a leak from one or more air springs. There is at least one slow leak from one front spring; now that I have the car on manual bike-pump-up, it does drop a little overnight; about 20 psi from one front spring. BUT I don't think that was enough to shut the system down; when the EAS was working well, it would pump up immediately and instantly in the morning. But that doesn't mean there aren't other leaks in the springs that aren't obvious in normal driving height. I'll fix the valve block first.

2) When I rebuilt the valve block two years ago, I replaced the EAS drier with a 'new' one as the old one had spread powdered dessicant through the system. What I now suspect is that the new one had been sitting on the shelf for years somewhere with the dessicant rotting over time; there is now a fresh load of powder throughout the valve block. I'll pull it out soon and report. If so, the lesson will be to replace the dessicant with new FRESH beads when the valve block is rebuilt. I think I've seen new dessicant on eBay. Apologies if this has been covered before.

3)
 

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Discussion Starter #9
3) was going to be that I realised that if the system is trying to pump up and can't get there because of leaks, it will throw up a hard fault. I have ordered an EAS kicker so I can reset the system myself.

Thanks to all
 

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3) was going to be that I realised that if the system is trying to pump up and can't get there because of leaks, it will throw up a hard fault. I have ordered an EAS kicker so I can reset the system myself.

Thanks to all
An EAS kicker only masks the issue because you clearing the fault instead of reading the code or codes the set the hard fault. Download free EAS software and either make or purchase the cable.

Nope on the english springer... close. I have been in Cocker Spaniel rescue over 30 years. That is William Arthur Philip Louis Windsor... Willie for short. He is an English Cocker Spaniel. He was a science experiment dog that was dumped.. I got the call at 8am and hes was so bad he was going to be euthanized at 4 PM.

 

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1995-2002 Range Rover P38A
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+1 on the leaking diaphragm. It is there to shut off the exhaust when the compressor runs. Classic test is to unscrew the silencer and put your finger over the exhaust when the compressor is running. It should be a tight shutoff. When it gets bad the system will never pressurise.
A couple of tricks I have learnt to revive the dessicant is to slowly pour the dessicant from one container to another outside on a windy day. The fines will blow away. Then microwave the dessicant in a shallow container with occasional stirring. You can see steam coming off.
 

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Whilst you have the valve block out to fix the leaking diaphragm, check the driver pack connector pins & sockets inside the plastic housings. These often have loose contact (even when housing is tight) and cause the random high mode. The fix is to remove each socket contact in turn and gently squeeze them so they make better connection to the pins.
 

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Discussion Starter #13
I nailed this. For now at least!

The random height rise issue got worse; I initially could lower the car to normal height by pressing the dash switch but it soon developed into an issue the switch would not correct. I disabled the EAS and ran it on manual pump-up for some time until I got around to it.

Each time I tried it by putting the relay back in it would work for ten minutes or so then fault by rising up and staying there with the system pumping air into all four springs with no stopping.

1) I checked all the connections in the EAS box; even taking each little terminal wire out of the top multi plug and connecting each one directly. The bottom multi plug seemed OK; I just hit it with contact cleaner. The fault persisted.

2) I cut off the white connector behind the LHF kick panel and soldered and heat-shrunk every wire. That plug was corroded and green. The fault persisted anyway.

3) This lead me to think the driver pack was the culprit. I bought a second hand valve block with driver and compressor on Fleabay. Put it in (with my good compressor) and went for a drive. Fault gone! But that valve block had leaks so I put my old valve block back in (as I'd rebuilt that one a couple of years ago and knew it was leak free). So I had a new driver pack with the old valve block.

The random height rise issue returned.

4) I rebuilt the new valve block as I had a spare O-ring kit and put it in. Fault gone again.

This leads me to think that the fault is either in one of the NRVs OR the compressor cut off switch (as I had not taken that off the block when I swapped them).

But how could that be so. Could the NRVs get stuck? I took a look at them; it's hard to see how they could be the cause.

Was it the compressor switch faulting; and how?

The fault seemed electronics related, not mechanical.

I tested the compressor pressure switch: it's zero Ohms at rest.

Any ideas?

Thanks from Tom
 

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Did you re-tension the contacts in the plug between the driver pack and valve block? It is common for them to lose tension so you don't get a decent connection. The fault will often be intermittent too.
 

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Discussion Starter #15
No, in a word. I shone a torch in that plug and the terminals seemed pretty tight. I just sprayed some contact cleaner in there.

I wonder how that particular plug could cause the random rise. It's just a block of outputs to the solenoids which supply 12V to each solenoid when needed. The random rise seems like a logic fault.

It seems there's no definitive consensus on the reasons for this fault. Looking at the pics on the guts of the driver, it's got one big filter capacitor for smoothing the 12VDC supply, several driver transistors to control each solenoid then the rest is voltage comparator ICs which don't fail intermittently; same for the driver transistors. Electrolytic caps are far more likely to behave randomly but there aren't any. None of those semiconductors would usually do that. It may be dry joints in that driver block. There's nothing else there that would go intermittent.

It could of course be coincidence but my fault followed the swapping of the valve block with the compressor shut-off switch. I'm left wondering HOW either the NRVs or the CSOS could cause the fault. I'm about to rebuild that block again and put it in to test it out. The NRVs in that block had a slight silvery oily residue on the O-rings on the NRVs but I don't see how they can fail. Should the seating surface of the NRVs be polished or smoothed before reassembly?

Thanks from Tom
 
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