Hi guys,

Got another fault with my L320 RRS and wanted to know if a faulty valve block could cause it.

Basically had a suspension fault last autumn so overhauled the o rings and drier medium and all has been good.

Over the past few weeks I've noticed when starting that there is an audible click or twang from the front valve block area this can be heard in the cab.

I'm now getting error codes first was c1a20-64 and normal height only this would reset on restart and suspension would work as normal gallery pressure would rise and exhause although front would raise slowly.

Now over the past 2 days I'm now also getting c1131-92 and will not raise gallery pressure will not rise to over 400kpa and drops to 100kpa.

I have ordered a salvage front valve block and set of o rings but just wanted some input that a bad valve block could cause this to happen.

Ok so just been out and the whole suspension is starting to sag, the front is the same height but the rears are getting to the same point now and alot lower than normal on the onboard display, it's also flashing raising/normal and on the dash it's saying suspension fault then normal height only so I think the height sensors are calling for air but then the system is saying there's a fault.

My driveway dips were the front wheels are so my guess is it has self levelled at the rear but as it cannot get any air on startup then it stays at that point and will until I fix it it.

Drives like a pig but I've got no opinion than to drive it this week until next weekend.

There's still the click from the valve block when starting and also when exiting the vehicle.

Probably find the compressor has failed...

Hmm you've got me worried now think I'll be ordering a compressor just incase and return if not required, the compressordoes run until the ecu throws the fault, don't want to be emptying the rest of the air out and be stuck on the bump stops.

Just had a look at the compressor and centre valve block all seem OK compressor runs until the fault occurs, although there is some white powder around the dryer seal and a couple of the voss connectors on the valve.

Managed to get the rear bags up a bit but the fronts won't budge.

I'm hedging bets now that there's a leak in the front valve somewhere and it has let water into the system breaking down the medium and blocking the valves in the block.

Busy weekend for me.

That is exactly what will happen due to low output from the compressor

Obviously, don't rule out a leak, but also don't overlook the obvious

C1A20-64 is pressure increases too slow
C1131-92 is air supply - component failure

Usually both codes are interlinked as the compressor fails, it's output is lower than normal, and logs the 1st code. Ignore if for long enough, and the 2nd code gets logged

Yeah your probably right I've got a new AMK on its way we'll see what happens, i think its just wishful thinking that it will be the valve and won't have to cough up the dough these things cost a fortune to run hate to think how much a garage would have charged for everything I've done.

Ok all good changed front valve block and compressor the one that was in must be original as said I reconditioned it 6 months ago but it certainly looks past it.

That compressor has a built date of 21-02-2013 it seems so it's done pretty well! 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed