Constant height adjust after bag change

Hey lads, changed the 2 front bags and reconditioned the compressor a few weeks ago, goes up and down now no prob BUT...
Got the EAS software etc and it's telling me that the left side (back and front) is sitting higher than the right, on level ground, tried a few different places!
Also, driving down the road it's changing heights on the front now and then just goes up or down whenever it feels like it
Could it be height sensors? never did this before bag change...
cheers

The readings from the height senors you see on the EAs softwate my well be different, what matters is the measured height from the wheel centre to the wheel arch. If the front is moving up and down I would suspect the height sensors have moved further than normal and disturbed some crap on the resistive track, might settle down after a while. Check the exhaust filter on the valve block for signs of white deposits which would indicate the air dryer is breaking up. This can cause strange things to happen.

Cool, thanks Keith.
would it be worth taking the sensors off and running them through full movement?

got the software and lead too, cheers

Go for Datatek's first recomendation and check for white deposits. It's possibly the dessicant from the air dryer breaking up and clogging a valve. Mine did this a few weeks ago and the front was raising up to extended (emergency above off road height) height by itself. Changed the sensor (unnecessarily i still think) then the air dryer and it has all stopped.

Unscrew the exhaust air filter from the EAS block and shake it - see if white dust/particles drop out - good news, Air dryer is only £40. few people had me worried it was the driver pack @£200!

See if you hit the brake the up and down stop, for example in a STOP or red light, or open the door...

But the best way is to wait until the compressor stop(door open), then select off road position, after that select normal with door closed.
If the RR start to going up and down, check if this movement is related to the compressor start and stop....

If this happen, you have a leak on the Non return valve in the block.

( language issue, but hope that you understand what I mean)

tomcatrr said:

See if you hit the brake the up and down stop, for example in a STOP or red light, or open the door...

But the best way is to wait until the compressor stop(door open), then select off road position, after that select normal with door closed.
If the RR start to going up and down, check if this movement is related to the compressor start and stop....

If this happen, you have a leak on the Non return valve in the block.

( language issue, but hope that you understand what I mean)

Click to expand...

Which NRV can cause that then 1, 2 or 3?

wammers said:

Which NRV can cause that then 1, 2 or 3?

Click to expand...

Wammers, can´t help you, with that but I think it´s the one witch is in a "different" position... or perhaps not, but I remember, we have a NRV that have more "damage" than the others ones.

Don´t try to understand Portuguese see the photos : (Photo 7 ) www.ForumLandRover.ORG :: O Portal Técnico sobre Land Rover em Português

P38_love/hatething said:

Go for Datatek's first recomendation and check for white deposits. It's possibly the dessicant from the air dryer breaking up and clogging a valve. Mine did this a few weeks ago and the front was raising up to extended (emergency above off road height) height by itself. Changed the sensor (unnecessarily i still think) then the air dryer and it has all stopped.

Unscrew the exhaust air filter from the EAS block and shake it - see if white dust/particles drop out - good news, Air dryer is only £40. few people had me worried it was the driver pack @£200!

Click to expand...

£24.99 plus VAT from Island 4 X 4 so less than £30

tomcatrr said:

Wammers, can´t help you, with that but I think it´s the one witch is in a "different" position... or perhaps not, but I remember, we have a NRV that have more "damage" than the others ones.

Don´t try to understand Portuguese see the photos : (Photo 7 ) www.ForumLandRover.ORG :: O Portal Técnico sobre Land Rover em Português

Click to expand...

Well it certainly can't be NRV 1 or 2. It can only be Exhaust tract NRV 3 and for that to happen exhaust valve would also have to leak and the two front valves would have to be open. When the front sensors reach their setting the front valves would be closed preventing any air from entering the bags. So i don't see how a leaking NRV could raise the vehicle to max height. But stranger things have happened i suppose.

wammers said:

Well it certainly can't be NRV 1 or 2. It can only be Exhaust tract NRV 3 and for that to happen exhaust valve would also have to leak and the two front valves would have to be open. When the front sensors reach their setting the front valves would be closed preventing any air from entering the bags. So i don't see how a leaking NRV could raise the vehicle to max height. But stranger things have happened i suppose.

Click to expand...

Wammers, your are right, if everything it´s working right.
Believe me, I had my RR "dancing" in the red lights, (going up and down only the front).
I try to find the solution in the web (could be a bad sensor, bag, BV etc....).
Then I found somewhere, if you have the "dance" the problem was in the NRV.
But the problem (NRV) it´s related, every time the compressor start.
That´s why I advice "But the best way is to wait until the compressor stop(door open), then select off road position, after that select normal with door closed.
If the RR start to going up and down, check if this movement is related to the compressor start and stop....".

I agree with you, it make no sense:doh:, the FR and FL valve should be closed, when the compressor is working to reach the +- 10 Bar.

Anyway with need more information from drscoundrel, because he says that´s only the front that is going up and not all RR (eventually the drive pack syndrome).

Anyway, perhaps a BV rebuild will cure everything.

(must love this cars)

tomcatrr said:

Wammers, your are right, if everything it´s working right.
Believe me, I had my RR "dancing" in the red lights, (going up and down only the front).
I try to find the solution in the web (could be a bad sensor, bag, BV etc....).
Then I found somewhere, if you have the "dance" the problem was in the NRV.
But the problem (NRV) it´s related, every time the compressor start.
That´s why I advice "But the best way is to wait until the compressor stop(door open), then select off road position, after that select normal with door closed.
If the RR start to going up and down, check if this movement is related to the compressor start and stop....".

I agree with you, it make no sense:doh:, the FR and FL valve should be closed, when the compressor is working to reach the +- 10 Bar.

Anyway with need more information from drscoundrel, because he says that´s only the front that is going up and not all RR (eventually the drive pack syndrome).

Anyway, perhaps a BV rebuild will cure everything.

(must love this cars)

Click to expand...

Every time vehicles stops (below 1mph) both front valves open to equalise pressure across axle. There will always be more pressure (depending on weight of driver) in O/S bags. This will cause front to drop slightly as pressure equalises. Then air will be fed in to raise car back to setting. This happens every time you stop, so in slow traffic the car may appear to dance. One thing is for certain, if the compressor is running the car can only go up, it cannot go down. Because air can only be exhausted when the compressor is off. For lifting to take place NRV 3 would be shot. Exhaust valve leaking and both front valves open. So yes in an extreme case you could get lift with compressor running, but it can only go up, it cannot go down with compressor active.

wammers said:

Well it certainly can't be NRV 1 or 2. It can only be Exhaust tract NRV 3 and for that to happen exhaust valve would also have to leak and the two front valves would have to be open. When the front sensors reach their setting the front valves would be closed preventing any air from entering the bags. So i don't see how a leaking NRV could raise the vehicle to max height. But stranger things have happened i suppose.

Click to expand...

Tony, get enough dessicant in the valve block and it does some very strange things, I've actually seen it happen, the front of the car rise, no idea why it should just affect the front, when it rises enough, the ECU attempts to drop it back to the correct height. sometimes it does it once and settles sometimes the cycle repeats. Valve block in question was chock full of dessicant. As I said a thorough clean, new "O" rings and diaphragm problem solved Of course there could be several other reasons for this problem.

Datatek said:

Tony, get enough dessicant in the valve block and it does some very strange things, I've actually seen it happen, the front of the car rise, no idea why it should just affect the front, when it rises enough, the ECU attempts to drop it back to the correct height. sometimes it does it once and settles sometimes the cycle repeats. Valve block in question was chock full of dessicant. As I said a thorough clean, new "O" rings and diaphragm problem solved Of course there could be several other reasons for this problem.

Click to expand...

Yeah i know strange things happen Keith. Just that car cannot go down whilst compressor is running other than by equalisation of front axle. No air can be exhausted with compressor running it's not possible.

wammers said:

Just that car cannot go down whilst compressor is running other than by equalisation of front axle. No air can be exhausted with compressor running it's not possible.

Click to expand...

wammers, nobody says this happens.

The compressor should run, until you have +- 10BAR or 150 PSI.

If the front raise with compressor running and go up than normal height (like datatek also reported), the ecu stop the compressor and level to the correct height, then the compressor start again to have 10 BAR, and the cycle goes one....

One way to stop this, is leaving the engine running with a door open.

wammers said:

Every time vehicles stops (below 1mph) both front valves open to equalise pressure across axle.

Click to expand...

It´s a new for me.

tomcatrr said:

wammers, nobody says this happens.

The compressor should run, until you have +- 10BAR or 150 PSI.

If the front raise with compressor running and go up than normal height (like datatek also reported), the ecu stop the compressor and level to the correct height, then the compressor start again to have 10 BAR, and the cycle goes one....

One way to stop this, is leaving the engine running with a door open.


It´s a new for me.

Click to expand...

It might be new to you, but that is what happens. I do know just a little bit about the EAS system.

Suggest you all read Tech bulletin #0007 CDs ref L8473bu issue 1, dated 04-11-98.
Vehicles between vin # VA346794 and WA409701 may have a problem ECU fitted, that does not interpret the sensor readings properly. Way to find it is to lower axles to bump stops on level ground and take sensor readings. If any are below 42 bits, ECU is to be changed from part # ANR4499 to RQT100040. This does not of course mean that every car that plays up has a duff ECU, but it does indicate that incorrect sensor reads or inconsistent reads from sensors can confuse the ECU. I think most of these problems are down to sensor malfunctions. And the valve block if in good order is just doing as it's told to do by a confused ECU. Ok you can have a leaking NRV. If #1 leaks you won't get any pressure in tank. If #2 leaks and you have no pressure in tank you will get air filling tank from bags and car dropping. If #3 leaks you will get high pressure air against exhaust valve. But to get any of that air into a bag the exhaust valve must be leaking, the four corner valves must also be leaking or open. Too many if's or have to be's for that to happen on a regular basis. You might like to ask the question that if NRV #3 leaks and air gets past the exhaust valve and into the air bags because it can't handle the pressure. Why does air not leak past the inlet valve and cause the front to rise, it has high pressure against it all the time. I don't think NRVs cause this problem nor do they cause the dancing. Inconsistant sensor readings could though.

wammers said:

Yeah i know strange things happen Keith. Just that car cannot go down whilst compressor is running other than by equalisation of front axle. No air can be exhausted with compressor running it's not possible.

Click to expand...

I didn't say the compressor was running, it ran only to restore lost presure. Air can leak out the exhaust with the compressor running if the block is full of the white ****. It sets hard like concrete and builds up on some surfaces, I assume because the dryer is stuffed the air is moist leading to the white powder amalgamating into a solid. Very difficult to remove all traces.

Datatek said:

I didn't say the compressor was running, it ran only to restore lost presure. Air can leak out the exhaust with the compressor running if the block is full of the white ****. It sets hard like concrete and builds up on some surfaces, I assume because the dryer is stuffed the air is moist leading to the white powder amalgamating into a solid. Very difficult to remove all traces.

Click to expand...

I've just answered this in length and the bloody site has gone tits up and lost the post. I am trying to address the OPs question of why front rises spontainiously. I have answered it but people keep coming in and saying well we cured ours by fluffing the rear set cushions up or nonsense like that and the thread has now got slightly jumbled up. Think your confusing which exhaust i am refering to. I always say treat EAS as two seperate items. Pressure gathering and storage and pressure distribution, i refer to the distribution exhaust valve not the diaphragm valve. In this case if he changed the front bags and did nothing else logic would point to sensors moving out of their comfort zone and causing the trouble simple as that.