Don't understand - if its a cordon what do you mean by the leader? if you cut all the side branches off to the leader surely it won't be a cordon any more? Or have i misunderstood you?

Stera, cordon training is a method of saving space and encouraging early ripening, especially in climates with cooler summers, by restricting the trees to a single stem 2-2.5 m tall. The stems are usually trained to slant to the north, perpendicular to the summer sun, and side branches are pinched out when only 3-4 leaves long, encouraging the formation of fruiting spurs. I think Petlynne wants to know if she can restore a neglected tree to it's original training, and when is the best time to perform the major pruning involved.
Petlynne, a picture of the tree would help us to know if you can fix it all in one go, or need to take it in stages. The proper time to prune is best answered by those who know the timing for the UK--rather than a desert rat like me! :)

Was confusing it with espalier,why don't i keep my big trap shut.

PS I did actually have a memory test this morning - a pleasant lady from the memory Clinic came to the house and was with me for and hour and a half.To my relief she said i was OK, hurray. (I don't necessarily agree though...)

Stera, your not alone, but it's good to hear the results of your test are positive! I had a test once, and they said I had a near eidetic memory. I knew better, though...I remembered all of the times that I had forgotten things! ;)

Hi all I have updated the question to include a picture. As you can see there are three side shoots coming from the main stem. I have been getting fruit but not much. This year only 4. My grandson was gutted when I said it was past redemption and needed to come out so I promised him I would see if anyone could help me to get it back to normal. Hope this helps to solve the muddle up.

Having seen the photo why don't you turn it into a three stem espalier instead of cutting all those healthy looking branches off? You could hold the two laterals back with long canes if you didn't want to wire the fence. (I have done that twice when training a pyracantha on house wall or a fence and it worked well - only needed for new growth as when it matures its already bent to shape.Then all you need t do is keep the laterals horisontal and remove any growth on them that you don't want (but don't cut off the bits that should flower...)

Well, pruning by itself isn't going to restore bearing. In fact, it will probably reduce bearing for the first few years.
The first thing that I would do is clear out some of the surrounding brush and vines that I see, to reduce the competition. If you choose to keep it as a cordon, I would stake it up at the proper angle, and cut the side branches back by half, cutting just above one of their side branches. Next spring and summer, more side branches will hopefully spring out along the bare trunk. Those should be pinched off at 4-6 leaves, while the new growth from the older side branches is pinched off at 2-3 leaves. The next pruning season, the older side branches should be cut back to 10-15 cm long. Hopefully, by the third summer, the tree will look like a piece of woolly green chenille standing in the garden, with nothing but mulch or a few small perennials around it, and the new tufts of twigs will be developing fruiting spurs.
One other consideration: how much shade is the tree getting from the fence behind it?

Tug an eidetic memory would be wonderful! Does it work for peoples faces too?

Supposedly, but I couldn't say from personal experience--though I do forget names faster than faces. :)

I tried mnemonics for names a while back - Pauline has Pale hair, Linda is a bit Lumpy, Maureen has a Maroon stripe on her trainers and it did help quite a bit (as long as Maureen doesn't buy new trainers...)

Thank you so much for your help. I've decided to try tugbrethils idea and cut back by half etc. The vine that you can see is a winter flowering jasmine that is planted a couple of meters away so it shouldn't interfere with the pear. The problem I do have is an ivy that covered the fence. However over the past month I've been dealing with this one bin load at a time and I'm nearly sorted. So it will be cleared soon. The fence is east facing and the small fence with the vine was erected to stop dogs and children getting to the pond unsupervised. The problem I will have is how to stop the ivy coming back through the fence. Again thank you for your help.p.s. I'll have to try that technique you use to remember names with my mum. We use white boards for important dates etc. I even use one myself now to remind me to do things. Lol. X

On an east facing fence watch out for late frosts when your tree flowers!

Well, Petlynne, for something the size of the average Winter Jasmine, not interfering means being planted at least 4 meters away, especially since its foliage mass seems to be surrounding the base of the tree. There's something red blooming at the bottom of the picture too--or it might be a Pyracantha or Cotoneaster with berries, though that may be an even greater problem.

You're right its a pyracantha but that will be coming out when i get chance and the area around the bas cleared. Its mainly that dam ivy and plants in pots. The jasmine is over the other side of the small fence and i guess it's about 3 mtrs away. I've just wound it around the small fence on the right to tidy it up. It needs to be attached to the back fence which i will do when ive cleared the area. But the root ball is over the other side of the small fence. Hope I've explained this better lol. Thanks again for your advice. X

You're welcome, Petlynne! 3 meters is better than 2, anyway.
For everyone who reads this thread:
Remember that a wooden fence has no effect on root competition, and even masonry only stops the roots of herbaceous plants and very small shrubs.