Rads Hot at top cold on bottom

I have just removed and adjusted the microbore pipe work in my lounge so I can install a small column rad, it is smaller in length and height than the panel rad before it, heating worked great on initial start up, how ever after the removal for decorating purpose the dining room rad on installation the system now has out of 7 rads 2 upstairs warm/hot D/room hot at top cool bottom, Kitchen red hot, hall and bathroom same as D/room, lounge warm at top cool at bottom.
Boiler is Worcester 28CDi, I have drained off through the locksheild drain offs about 4 buckets of water now in case there is a air block in the return system water is very light brown to clear depending on which rad it is, I can\\\'t see these rads sludging up over a couple of days, system was running fine, it is not zoned, HW is ok, pump is working, and have opened the air bleed but just water comes out, all the return locksheilds are luke warm, TRV\\\'s Hot apart from the kitchen rad which works as it should, do you think there is air in the return side of the system. if there is how do I remove it, or should I drain down completely and refill again?

The lockshields are usually adjusted to balance the flow equally through the system. Radiators nearest the pump are closed more than those further away. You may have upset the balance by changing the positioning of the lockshields.

Try turning all of the radiators off exept one that is not as it should be. Turn the hot water off at the same time for max pump flow through the problem radiator. Sometimes that will force the water though.

If it works repeat one at a time for all of the others.

You still may have to rebalance the system once all of the air is out afterwards. Do a search on this site, its been explained lots of times.

Locksheild balance has remained the same on all rads apart from, the D/Room, which was closed but number of turns counted, same rad back on opened to the correct amount of turns, the only one which is not accounted for turn wise is the new column one in the lounge, And on reflection I did open the flow side first then answered the phone to some survey rubbish, closed the flow valve topped up boiler opened flow valve to fill more, then realised return valve was still closed, rad now half full, so I opened the return, I wonder if the air in the return was then pumped through the system and is stuck some where now on the return side.
if I try shutting them down one at a time and this doesn't work, could I use my filling loop at the boiler to push out the air via the returns, if I close all the TRV's then use a hose and open the drain off on the lockshield a few turns then use the mains pressure through the boiler to push out the air, kind of like flushing the system. do you think that will work or shall I just shut down the rad I am on, you know what they say, don't fix it if it ain't broke, well I fixed it, and now it is broke!
I tried a search on this site and many others they mainly concentrate on cold rads, sludge, or cold @ the top none fit the pattern, apart from sludge, but with the amount of rads that have been affected so quickly I would have thought the system would have been misbehaving much earlier, incidentally the pipe I had to shorten was the return pipe, coincidence eh!
Thanks
Chris