Ok got to my drop and the suspension on my skelly is in the lowered position. Thought it was weird as I always check the handle. On looking at the handle its in the road position but the suspension is down. After 30 mins off taking lines on and off and looking for leaks no joy anyone got any idears. It’s an old style skelly with the leaver in frount of the 1 axle. Thanks
‘Idea’ number 1 … The lever is incorrectly fitted, sometimes during repairs the fitters don’t give a toss how they replace things, try another setting.
‘Idea’ number 2 … Bad conection at the serivice line.
'Idea number 3 … Faulty air bags.
there may be a box with a lock which has the air controls inside for manual adjustment,the last person may not of set it to self level.
Rubber boot slipped on the self levelling / load sensor valve. Will need loosening and moving to suit.
Its not one of those levers you have to push in to get it to ride right? Pull out to
Adjust up and down, push in to self level. Someone might of been playing,
Thanks for the tips moved handle in and out. I think it must be the sensor. On the phone to the office it is then!!
Yeah as one fella said, it’s the load sensing, ride height valve. You can usually move the arm up and down and gaffer tape it in a neutral position if its cone loose.
Where is said arm located please
On or around third axle 
tiny vertical rod into a rubber grommit 
HTH 
And sometimes if you go up on a high kerb or a speed hump, the lever can go over center and flip backwards. It wil be the only valve with an arm and rod connecting it to the axle and it will more than likely be on the middle axle
Weird ended up taking trailer to fitters they looked at it for an hour tried everything no joy. In the end boss say come back to the yard in the morning. Brakes locked on comming out of the fitters yard get that sorted but abs fault on dash. Then pull in for the night at the services and the suspension is in ride position and handle works fine. WTF !!!
there is just one more handle you need to pull that will solve everything!!!
Hmmm… suspensions down… brakes locked on coming out the yard…
Time for a new pair of C couplings up front me thinks… connected… not leaking… not opening either 
Worn C couplings on trailer, suzies or both. Trailers not getting enough air.
And your man above is a mech so that’s your best bet.
You’ve been quiet lately Cieran.
Yeah cieranc may have hit the nail on the head with that. I had that happen to me not long after I bought a merc actros pulling a Safeway trailer. Couldn’t for the life of me work out the problem of why the trailer brakes would come on whilst driving down the road, turned out that the gubbins inside the red air line coupling of the tractor unit wasn’t moving to seal properly round the end bit in the trailer.
Most modern level valves have a “run to ride” solenoid on them.
The abs on the trailer once it senses travel above 10 km per hour should automaticaly kick the valve into run position to protect the bags and dampers.
Air bag leak wont affect your braking system even if all 6 burst.