Busted rear air shock?

[morpheus]

G'day all,

Has been a while since I posted last - only just did the subscription thing. I have done something to my rear suspension. I have had a crunchy noise when going over bumps at low speed, and the other day I got the amber light and suspension fault - normal height only warning. I don't think it is the compressor as I only just had a new one installed. I started to suspect rear lower arms when I found a bit of a discrepancy between the rear shocks...

[Graeme]

That's only the dust protector but the air-spring itself might be damaged too.

[morpheus]

Yeah. The crunch sound probably isn't the best description. It sounds like bouncing on a lot of old rubber. The dust cover looks like it is stuck hard up there.

[Drizzle]

Trim the old strut dust cover rubber boot away and see if the noise ceases.

Hopefully this is the cause of your noise as they are relatively cheap as a replacement kit. The part number is RPM500200.
http://www.island-4x4.co.uk/boot-gaiter-rear-strut-rpm500200-p-26160.html

[morpheus]

Thanks. Will give this a go! Would the cover being stuck as it is cause the fault though? I must admit there are a few other electrical issues going on so the fault might not necessarily be linked to the EAS at all. The car has done 242k kilometres, and I have had to replace the front lower control arms recently so these things are starting to get to the end of their tether. How long do the rear springs tend to last anyway? I do have a lot more weight in the back than normal too (rear wheel carrier and long range tank).

Thanks

[Graeme]

The normal height only message occurs usually when the compressor is too slow at filling the reservoir which could be for several reasons including a leaking air-spring causing the compressor to get too hot in levelling work even before starting to fill the reservoir. However in the absence of a leak, it normally indicates a failing compressor due to a blocked dryer, a worn-out compressor valve or a worn-out compressor.

Remove the 20A main suspension system fuse from the engine bay fuse box overnight and see of the vehicle drops at 1 corner, normally indicating a leak in that air-spring. If no corner drops and the compressor hasn't been overheated from too many height changes in quick succession then the compressor needs to be investigated.

[Pome pilot]

I'm also having suspension issues (again!!)

I have just pulled the fuse and taken some height measurements to try and do my own fault finding before resorting to taking the car to the garage.

Q. In the event that a faulty air spring is the cause of suspension faults, are you required to fit new air springs for that axle (as one would on conventional suspensions) or just replace the one that has a leak?

We had a new compressor fitted in March to sort out suspension issues that reared their head last September and here we are having done a similar road trip to last year with what appears to be the same problem.
The car behaved perfectly after the new compressor and software update were installed, but after 6000 kms loaded up, towing a camper trailer and doing a fair amount of dirt roads the car is taking to sitting down again from time to time - the OSR seems to be the culprit but will see what the overnight experiment shows.

[Graeme]

Good practice to replace both because if 1 has started to leak then the other wont be far behind as cracks develop at the folds. Its cheaper to replace the shock / air-spring assembly than just the air-spring so another good reason to replace both.