Disco 2 Air Suspension Ups and Downs

2003 Discovery 2 Td5 - rear air bags were replaced in 2012 by LR dealer (genuine LR boots); the compressor hasn't been touched since purchase in 2003.

All has been good and no noises or anything unusual. Have towed a tandem trailer recently on several occasions and noticed several days ago just before I got home with the trailer that the ride was rather floaty! When I got home I noticed that the driver's side rear was right down and I had probably ridden on the stops for a couple of kilometres. Anyway, I unhitched the trailer and it went up again and was fine next morning. Drove with the trailer again the last couple of days (two separate occasions and both longish trips) and it was spot on all the way both times - never dropped (loaded or unloaded) and the ride was perfect with no tell-tale noises from the compressor. Is this the start of something? Hate intermittent/unexplained problems!

The level sensors are both original, as is the compressor; bags replaced in 2012.

I was thinking of buying a seal kit (with dessicant) from 4x4airseals.com for the Wabco compressor - preventative, proactive maintenance I guess. Fairly cheap so might just do this regardless.

I notice the level sensors are relatively cheap - wonder if the driver's side level sensor maybe got stuck?

Hopefully the air bags are okay.

Any thoughts?

I would say definitely change your ride height sensors. One of mine got stuck last year after i had driven in a sudden dip. My drivers side air bag went up to maximum. Both ride height sensors were still attached and looked fine but when i disconnected them and pushed the link arms up and down I noticed that although the passenger side operated the spindle shaft ok that the drivers side arm was just spinning on the spindle and not operating it. The spindle was stuck in the maximum position. I replaced both sides and all fine since.

Interceptorxj said:

I would say definitely change your ride height sensors. One of mine got stuck last year after i had driven in a sudden dip. My drivers side air bag went up to maximum. Both ride height sensors were still attached and looked fine but when i disconnected them and pushed the link arms up and down I noticed that although the passenger side operated the spindle shaft ok that the drivers side arm was just spinning on the spindle and not operating it. The spindle was stuck in the maximum position. I replaced both sides and all fine since.

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Thanks for that, incidents sort of fit in with a sensor that gets temporarily stuck? Might take both off then and see how "free" they are. I read just a few minutes ago that you should disconnect the battery before you remove/replace them otherwise ride height settings will go out of sync when the new sensors are connected? Looks like two sensors (OEM) from Rimmer Brothers are reasonably priced so they might be the go?

Will probably still get the compressor overhaul kit - just in case.

Noticed this in RAVE with regards to both height sensors:

"When the sensors are replaced or removed for any reason, a calibration procedure is required to recalibrate the sensors and the SLABS ECU. The calibration procedure requires the use of TestBook and calibration blocks to set the axle to chassis height to a known value."

Height sensors appear easy enough to remove - not missing anything there am I?

Am I right in assuming that if I disconnect the battery before I remove (and potentially replace) the height sensors then I won't have to do a recalibration? [I don't have Testbook - I have a Foxwell unit - not sure if it has a recalibration facility, probably does, but don't want to give myself extra work/complexity.]

Any thoughts on this?

Okay, went to us the Disco 2 today after two days parked. Driver's (rear) side right down! Started engine and expected (as happened before) that it would rise up after 30s or so. No luck - kept engine running for 5 minutes and it did not raise - normal on the other side.

Okay, with COVID-19 don't expect to be able to get parts in a hurry - 2 airbags and maybe driver's side ride height sensor. [Ideally need to use it in next few days to tow a trailer.]

Thinking! Maybe disconnect battery, jack-up driver's side rear and remove the ride height sensor and then swap it with the passenger side ride height sensor to see if that's the problem? Any thoughts?

Looking at the rear wheel though I can see it might be a struggle to get the bottle jack in there and jack it up???

Might bite the bullet and buy a pair of used suspension air bags from the wreckers and install one on the driver's side - other will be a spare. Awfully expensive it seems to buy new air bags!

Assume changing a bag isn't too hard?

Okay, was just about to order a new Contitech (OEM) bag online. Before that, I decided to go out and start her up - lo and behold, rear driver's side was pumped back up again to normal within 30s!

Inspected 3 hours later and no change - still perfect - so if there is a leak, it must be very small. Will check tomorrow morning and see if it has dropped! [Maybe leak only becomes "active" when the bag is in a certain position?]

Now, will likely still order a new Contitech bag (AUD 220 delivered) online, however I am wondering is it possible that the driver's side bag is deflating via the compressor - via an exhaust (solenoid) valve in the compressor - is this even possible? Otherwise the only explanation is a slow leak from the bag under certain conditions?

Seen this excellent video that I will follow. Might also buy two new clips in case the old ones break?



Now, I only (at the moment) have access to the LR bottle jack and two axle stands, is it still possible to change the bag over with this set-up? I notice in the video that he uses two trolley jacks - one underneath the tow bar and one underneath the rear differential.

Do you have a diagnostic tool ?

sierrafery said:

Do you have a diagnostic tool ?

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Yes, I have a Foxwell NT510. I did check an hour ago just out of interest and the only fault code that I saw was this:

"0E04 ECU fault (fault code 37) - Contact TestBook Helpdesk"


There are no warning lights on the instrument panel. The only tiem I warning light came on recently was a couple of weeks ago when I went around a bend (probably a little too fast) and the ACE warning light came on; I'm assuming the fault code above is a legacy from that incident?

That might be historical. When the vehicle is on level set the suspension to coils then you'll see if it's a leak or a management issue cos if it stays on level for days this way it's not a leak cos the whole management is disabled but if it drops on the same side the bag is leaking

sierrafery said:

That might be historical. When the vehicle is on level set the suspension to coils then you'll see if it's a leak or a management issue cos if it stays on level for days this way it's not a leak cos the whole management is disabled but if it drops on the same side the bag is leaking

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Still 100% this morning - must leak in certain positions when pinhole is exposed - I've read they can be unpredictable - on again/off again! Will order 1xContitech for now (COVID-19 has hit the back pocket hard) and replace once I get it; will do the other side later on when I have a bit more cash!

Went down again and back up later (same side) when engine started! So, just ordered new Contitech air bag - looks like a leak that exposes itself from time-to-time. Will fit it when it arrives (AUD 220 delivered) and then purchase one for the other side a little later when I have a bit more spare cash (COVID Credit Crunch).

Seems like a good plan

Now, bit of a simple fella - anything I have to do, I do it with my two heavy-duty axle stands and my LR bottle jack; I don't have a trolley jack(s) or ramps.

Just thinking, at this stage I'll only be doing one bag at a time (will purchase second bag for good side a bit later). Now, one of the videos I seen on YouTube (he was replacing two bags at the same time - see video on previous post) shows two trolley jacks - one jacking up from the tow bar and one jacking up the rear diff. Now, any safe suggestions on how should BEST tackle this doing one side with just the one bottle jack and the two axle stands (and up to 4" thick of sleeper timber to get extra height if required)? I can't see how I can lift at the tow bar end (too high) using the bottle jack. Obviously when I deflate the old air bag to take it out I don't want the vehicle to come down on me! Safety first, second and third! Usually I only jack-up at the jacking notch on each of the radius arms and then support at the radius arms with one of the axle stands.

Any safe suggestions or tips for best way to support both chassis and axle with just the two axle stands and one bottle jack (only doing one wheel at a time)?

Have a read of this link from UP http://www.discovery2.co.uk/Rear Air Springs.html
Griff

Okay, he's obviously doing both bags at the same time. I noticed he has a bottle jack, a trolley jack and two axle stands. I just have the two axle stands and a bottle jack.

So, plan of attack:

Level ground, engage park, Hi gear and handbrake on

Jack up at radius arm jacking location with bottle jack on one side and then slip axle stand in under chassis rail on that side (as per "discovery2" site)

Do the same thing on the other side

Go to side where bag is being replaced (will replace the bag on the passenger side in a fortnight or so) and put bottle jack under the axle so I can jack it up as required


Does that sound right, or is jacking up the axle only at one side going to potentially cause a problem? If so I might have to maybe hire a second bottle jack or a trolley jack?

IMO you are overcomplicating things, i changed the bags on mine one side at a time only with the bottle jack and one axle stand. Once is up enough to remove the wheel put the stand near the jacking point, remove the jack and support the body on that side with it that's all

Yeah,

I originally started out that way - didn't think too much of it, until I seen the video with the two trolley jacks - one jacking up high at the towbar.

Anyway, jack up at the radius arm jacking spot, then use axle stand to support at chassis rail, remove wheel and put bottle jack under axle (use if required to raise axle a bit to clip bag in at top mount).

I get a little worried with jacked-up/raised vehicles - a cousin of mine lost his leg below the knee quite a few years ago now - he was only 17; his dad's van was jacked-up and somehow came down on the bottom of his left leg - could have been worse! That's why I'm extra careful if I need to get under the Landy, or anything really!

Received my second Contitech air suspension bag today, so jacked one side up, took wheel off and used axle stand on chassis - all good. The bags currently on are LR Genuine Contitech - they both have the 10mm nut at the top holding the air-line - I believe these are called Voss fittings (10mm nut/olive/o-ring) - not push-fit (used on Dunlop bags?). I removed the wheel and removed the driver's side air bag - the 10mm nut wasn't accessible with a spanner (no room) to let out the air so I depressurised the air bag by loosening another 10mm nut on the driver's side air line back at the Wabco compressor.

The two new bags I received (Contitech OEM) both have the same 10mm nut arrangement on top (Voss fitting?) - I was under the impression that all new bags now used the push-fit (collar) securing mechanism, but maybe they're only used on the Dunlop bags? The strange thing with the new Contitech OEM bags is that the instructions with it say you should not adjust/remove the 10mm nut at the top of the bag (Voss fitting)! There is a dab of paint on the 10mm nut and they say it has been tested in the factory and won't leak in that position - do not adjust?! Surely I will have to undo the 10mm nut on top of each each bag so I can re-fit the black plastic air line using the old (existing) Voss fitting?

The old fitting obviously has the old o-ring (and olive and nut) and I wonder whether I introduce the possibility of air leakage once the air line is attached to the new bag?