sleep cot to bed

I thought DS was ready for a bed,. for mnths he has been fighting his sleeps in the cot.. screams and screams, but once asleep was sleeping all night in the cot,-. he is 23mnths.
he loves hopping in his older brothers bed, so we thought, yep , lets move him into a bed, he seems to love the bed, it has only been a few days,.. the last couple of nights have been shocking, he goes to bed ok, (well we do need to lie with him, or stay in the room, but he will go off to sleep, after half hr or so, )
But the problem is , he will be up at 1ish, 2ish and want to either hop in bed with us, where he just plays, or he will want brekky. the cot is still in his room, and we threaten him with it. he is only getting a few hrs of sleep a night,, maybe he is to young- anyone else having nightime battles with cot to bed.. I know his brother was bad, but once he was asleep he stayed asleep all night, not wandered the halls all night.. any suggestions
Thinking if he keeps getting up, put him in his cot, he will soon work it out, or do we take the bed out,a nd leave the cot in his room for a few more mnths