Bizarre cause of air suspension failure...

[Ozjood]

Hi Folks,

I don't know if any of you have encountered this situation before - it was incredibly frustrating at the time until the cause was established...

My wife and I bought a 2005 Discovery 3 HSE V8 in June 2011. To date its been great, other than encountering a few hassles when electric brakes were fitted (the causes being a combination of the installers wrongly wiring the Tekonsha P3 unit into the car, and a mobile phone being placed too close to the unit itself).

All was well, until I received the dreaded 'Suspension Fault - Normal Height Only' message upon starting one afternoon. I kept an eye on things but within a day it had progressed to the blunter message of 'Suspension Fault'. It was also evident that the compressor was not operating. Grumbling, I bit the bullet and ordered a new compressor from Paddock Spares in the UK, whose prices were certainly more reasonable than Australian vendors. By this time the Landie had sunk on its suspension. Rather than attempt the job at home with only car-spec jacks and ramps (a lesson has been learnt there!) I had the Discovery put on a flat bed truck to be attended to by a mechanic I trust.

Fitting the new compressor was a doddle, however on starting the Discovery rose only partially, the compressor working for a few seconds, then shutting off. New fuse and relay had been fitted, and they were intact. After another effort, and getting the same result, my mechanic shut the engine off and heard the sound of an air leak from the front left corner. After stripping away the wheel well covers the offending air hose was located.

Now this might not seem all that unusual, but the hose - aside from being split - was also sticky, perished and smelling of battery acid. Interestingly, this damaged portion of air hose was next to what appeared to be the battery vent tube. I also recalled that a new battery had been fitted to the Landie about 10 days before our purchase. All I can surmise is that either the previous owner or the dealer had tried to charge up the old battery, and either overcooked it (sending battery acid down the vent tube onto the suspension line), or found the battery to be beyond redemption and overturned it in trying to remove the battery out of the engine bay. Certainly, there was evidence of a fair bit of acid having got into the area, with lots of bicarbonate of soda now being needed to clear this mess up.

Anyway, all was well after removing the offending section of hose and fitting a repair section using high pressure hose and appropriate fittings. It goes without saying that the battery vent hose has been re-routed too, and I'll be checking whether the old compressor is in fact OK...

Cheers,

Jude and Andrew Matusiewicz
2005 Discovery HSE V8

[DoctorJ]

It would be interesting to hear if the compressor was faulty at all, I was told that my compressor may be faulty as it was very loud, but it turned out that the bracket needed replacing and that was it (it is now substantially quieter), would be interesting to know how many compressors get replaced due to their bad rap unnecessarily.

Cheers
Julian

[LRTech23]

The compressor probably burnt itself out trying to pump up the front left.

The compressor should run to at least fill itself up.

[Graeme]

The compressor should run to at least fill itself up.

What do you mean by this?

[101RRS]

What do you mean by this?

Maybe fill the air tank up????

[LRTech23]

As far as I'm aware there's a reservoir that the compressor replenishes.

[Ozjood]

Hi Folks,

Yes, there is a reservoir holding pressurised air.

In trying to understand what was afflicting our Landie, I came across the following.

http://www.disco3.co.uk/gallery/albu...escription.pdf

Quite interesting reading!

As to whether the old compressor burned out, I'll find out when I test it. I'd be surprise if it has, I would have thought that the 60A fuse for the air suspension would have blown beforehand (it hadn't).

Cheers,

Andrew Matusiewicz
2005 Discovery 3 HSE V8

[Graeme]

As far as I'm aware there's a reservoir that the compressor replenishes.

Ah yes, but only after having completed any raising requirements.

[LRTech23]

Yes Graeme that is absolutely correct.

And OzJood, they burn themselves all the time, trying to fill up the reservoir they can become too hot and just die. I'd say that 90% of the compressors that we replace have burned out.

I've never seen a blown fuse. Simply because it's not due to an excess amount of current (it could well happen I've just never seen it), the compressor just works itself too hard and the motor burns out, simple as that.

[Geedublya]

That's strange as it has sensors on the head and brushes to detect an over temperature situation. When the cpu detects an over temperature it stops the compressor and displays a warning.

If there was an air leak and it was running a lot more than usual I can imagine it would wear out the brushes or piston sealing faster though.