Flying Scotsman valve gear stuck in cylinder block

[Charlie Devon]

I am attempting to disassemble my 1970's Flying Scotsman to restore after 40+ years.  The valve gear is lodged firmly in the cylinder block.  It does not appear corroded and will waggle about but will not come out.  Is there some secret to doing this?  I could use bigger tools but am worried about damaging the block.

[81F]

 Do you really need to take it out or can you just clean both parts. while still fitted together?

[Tay00]

Have you dis-assembled the valve gear from the wheels? the runner into the block should be free running with nothing to prevent it sticking. The block could be worn meaning it's moving about too much and off its intended movement and carved its own slot after all this time. The block can be easily removed and new ones are available. Changed mine on a Britannia.

[Charlie Devon]

 Do you really need to take it out or can you just clean both parts. while still fitted together?

 The valve gear kept locking and on inspection appeared to have a lot of play in it so I have sourced some new valve gear hence the need to remove the old ones from the block.

[Going Spare]

Beware of being too forceful as the plastic of the cylinder block becomes brittle over time and, unless a source is known to Tay00, you may have some difficulty finding a replacement.

[81F]

 @ Charlie,

 

OK I understand now, my only concern was the same as Going Spare since I've damaged other loco cylinder blocks as he suggested. One tip however is do not do this in the cold or when the plastic is cold as it becomes more brittle. The damage I caused mainly occured in the winter when the Railway Room was at its coldest.