New Air Suspension Bags - Only one Inflates

Managed to replace air bags on V reg Discovery Td5 yesterday and followed instructions provided on www.discovery2.co.uk to the letter (excellent source of help).
After fitting offside rear bag I started engine briefly (to run compressor) to see if all was ok - it was. I then let out the air again at the compressor by removing the left and right pipes with the 10mm nuts on.
Replaced nearside rear bag and connected everything up and started the engine/compressor again. This time only one bag (the same as before - offside rear inflated). Did a few checks for leaks at the compressor/push fitting on top of bag and all seemed well.
Due to having limited knowledge I swapped the left and right air pipes at the compressor (thinking this would reverse the supply - left to right/right to left) and this worked.
I now conclude that both bags fill as they should but something has gone wrong at the compressor end?
I think I may have overtightened the nut on the left hand (nearside) supply pipe - if so, would I not hear air coming out? Anyway - can someone direct me to a schematic of how the compressor operates and tell me where I can get new "o"rings and compression fittings for the air lines?
By the way - the push fitting at the top of the air bag seems very unconvincing - will these "clamp" better when up to full pressure? Has anyone had one of these pipes "eject" after fitting?
Any advice would be most welcome.

you could try swapping the ride height adjusters around. do disconnect the negative lead from the battery first.

didnt u disturb the electric plug when u worked with the pipes on the valves? ... swap the electric connectors on the air supply valves, see what happens... we'll talk after that

Many thanks for suggestions. As the car was still semi-supported by axle stands I decided to remove these and see what happened first. Obviously the tow bracket was practically touching the ground however I started her up - and up she went - on one side only -again.
Slackened unions on compressor again and reversed connections (to see if I could get the other side up again). Succeeded so again presumed I must have some sort of air leak or height sensor issue. Removed pipes from compressor and noticed that one rubber "O" ring was missing. Had visited local LR main dealer in Knutsford a little earlier and very nice man had provided me with a couple of random rings - and one fitted nicely. Put it on - started the engine and nothing - so reversed pipework at the compressor and "voila" she rises up to correct height.
Been for test drive and all seems well. Even rises on pressing additional height switch. I am pretty certain that the pipes on the compressor are not back where they originally started -left to left, right to right. Is this likely to be an issue?
If I find her lying sideways on the drive in the morning I suppose I will have answered my own question.
Until then - all seems good.
3 amigos are next on the list - what fun!
Many thanks to all.

If the pipes are mixed then the SLS will work inverted, e.g. if u will put a bigger load on the right side of car the sensor will give the input but the air will go in the left bag, as the sensor will not feel the improvement the ECU will keep the compressor pumping in the left bag and it might overinflate/blow it... make sure everything is on right position. It's not a problem to make tests mixing pipes and plugs to diagnose things but at the end everything must be in original place.

Thanks for the advice. Now for the really stupid bit - if I have "crossed" the supply pipes is there an easy way of identifying left to left/right to right or should I just slacken the union to release the air then re-pressurise and if both bags fill - presume they are on the right way?
When I slackened the nuts yesterday at the start of my investigation the air "release" from the right union was actually air being drawn in to the system and not escaping - can't say I heard much or anything from the left union. All becoming a bit vague now

Here is the scheme of the compressor assy. Loosen the pipe from the LH valve and in this case the LH side must drop if everything is ok ... got it?

Success - but no success!
The pipes appear to be the correct way round and she dropped as expected. Sad thing is I think I have now stripped the thread in the compressor. Voss coupling will now not stay in place. Nice to see Land Rover made it out of plastic!
Is there anything I can do apart from getting a new compressor???

Try to use some epoxy or something.... that's why i advise everybody to stab the old bags and put the new ones without messing with the pipes/valves in the compressor housing

Had the same problem but i managed just by replacing the ride height sensor on the side that kept dropping down, fingers crossed been behaving ever since...
I was all ready to change bags, Sierrafeery pointed me in the right direction on things to check and ended up saving a fortune...

So listen closely to what hes saying and you'll end up with the right conclusion..

Thanks Sierrafery. I presume the epoxy should be put on the coupling thread rather than in the recess then pressed home?

U decide how it's better cos u see how it looks now.... i didnt have such a problem untill now but IMO a good epoxy will fix it cos it's not a huge pressure there(around 10 bar/140psi)

Pity I didn't know about "bag stabbing" before but we may have a success story. Had to take dogs to kennels which happened to be a few miles from a used Land Rover emporium, I managed to pick a used valve block for £20 and have now re-fitted everything and we seem to be in business.
If she hasn't capsized by the morning then I think my current problem will be over - then on to 3 Amigos etc.

Many thanks for all your assistance - I am sure I will be needing your wisdom in the not too distant future.

Great site and a great way to get things sorted through mutual experience/knowledge.

I replied to your advice yesterday but it seems to have gone AWOL. Maybe I didn't press the correct key on my computer keyboard?

Anyway - as I had to go and take dogs to kennels near Congleton there happened to be a Land Rover emporium nearby and I was able to get hold of the air pipe/switch block for £20. (I wasn't too happy using epoxy as it would have been a one way trip).

Fitted the new (replacement) block, connected up and everything now seems to been fine. The car drives well and hasn't sunk overnight. I think we now have a success?

Many thanks to all for input. I shall make sure I read deeper in future and will not forget the "bag stabbing" recommendation.