Thread: P38 EAS weirdness

<div class='quotetop'>QUOTE(strangerover &#064; May 15 2006, 07&#58;19 PM) Quoted post</div><div class='quotemain'>
Hello All, I&#39;m a sometime reader, first-time poster.

Front of my 4.0 &#39;98 is continually dropping when running- enough that the valve block raises it up a few clicks every minute or so. The compressor is running nearly all the time to keep up.
What&#39;s unusual is that it&#39;s across the front axle, i.e. it&#39;s not just one leaky bladder- or is it?
I&#39;ve had a bag go bad before, I diagnosed it by leaving a door half-ajar overnight, & came out in the morning to find the driver&#39;s side front corner down to the bumpstops- she certainly looked ridiculous with her bum up in the air. A new airbag fixed it- which means that the front axle has one newish airbag, and one original.
This is different. I don&#39;t understand it at all. It&#39;s as though the 2 front bags were connected somehow, but this is a P38 not a RR Mk3.
I&#39;ve sprayed detergenty water onto the side of the valve block, but seen no leaks- nor can I hear any, either from that valve block area or the bags themselves.

Ladies & gentlemen, your thoughts please?
I need to get this fixed by weekend after next- we&#39;re off to Mt. Disappointment for fun & games.
If I don&#39;t get it fixed, there could be more fun & games than I bargained for...

TIA
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It sounds like you know about the usual methods of testing overnight and if you tried them and the front is going down only while moving then you are losing air for one of two reasons;
1) you have a leak or leaks from airbags only induced by the vehicles movement or 2) the ECU is not putting out the correct signals and continually trying to correct itself.

Obviously this needs to be fixed or you will also be buying a new compressor very soon. My first suggestion is that you replace BOTH front airbags with new ones immediately. Airbags are no different to springs, shock absorbers, brake pads or discs, in that they MUST be replaced in axle sets or you are asking for trouble.

My suspicion is new bags will cure the problem. If it doesnt you&#39;ve wasted nothing but rather cured a potentially dangerous handling issue.

If bags don&#39;t fix it have a close look at the level sensors for signs of damage. After that I would say the valve block driver has possibly failed.

Thanks for replying.

The front of the car sinks evenly whilst sitting still, engine on or off. No rocking from side to side, it goes up evenly too.

What&#39;s the valve block driver?

& how sensitive are the bags to mud? When I popped the bonnet to check the valve block, I was reminded of how muddy my last excursion was- are engines meant to be light brown? I&#39;m wondering about dirt etc. in the bottom seats.

Valve block driver is the brains of the EAS system and prone to failure. Google for ANR3900.

From what you&#39;ve now said this sounds more likely but I&#39;d still put on a matched pair of bags first.

The airbags themselves are not sensitive to mud, but if you&#39;ve fully extended them in dirty conditions then I&#39;d say seating issues are a possibility. As are clogged level sensors.

<div class='quotetop'>QUOTE(P38ace &#064; May 15 2006, 09&#58;15 PM) Quoted post</div><div class='quotemain'>
Valve block driver is the brains of the EAS system and prone to failure. Google for ANR3900.[/b][/quote]

&#036;390US the cheapest I could find, plus shipping from the good ol&#39;
US of A. I do hope it&#39;s not that...

<div class='quotetop'>QUOTE(P38ace &#064; May 15 2006, 09&#58;15 PM) Quoted post</div><div class='quotemain'>Whilst the airbags themselves are not sensitive to mud, if you&#39;ve fully extended them in dirty conditions then I&#39;d say seating issues are a possibility. As are clogged level sensors.
[/b][/quote]

Time to jack her up for a clean then- any tips? Are the bags easy to pop out?

Thanks Ace