1.8 Freelander oil pump seal problem

Hi everyone. I have big problem with oil seal on oil pump. I removed oil pump housing, replaced the seal and when I put all parts back I had major oil leak. Housing off again and seal looks fine. Is there any special tool for this seal? It looks like is to short, not covering wider part of crakshaft.
I did it twice with big oil leak. I have seen seals for sale with kind of plastic tube. Is this tube design to expand this seal and help in any way with installation?
I am so angry because I spend two afternoons with no lack.
Thanks guys for any info.

Yes you place sleeve on crank and then fit seal, the sleeve prevents damage to the seal lips.