Did you see this in your search here at iboats?

Volvo does not officially offer a reseal kit for the SX trim cylinders. With that said, OMC does offer a reseal kit which I'm told will work to reseal the SX trim cylinders as the OMC cylinders were virtually identical. As a Volvo dealer, we do not reseal Volvo trim cylinders as that is not an approved method of repair, but one of our parts dept. personel advised me that he has sold the OMC trim cylinder reseal kits over the counter to other shops/individuals that will reseal Volvo trim cylinders.
It's worth a try, the OMC trim cylinder reseal kit part number is
985060 (cost is $27.25 plus tax) compared to a new Volvo SX trim cylinder which is ($472.50 plus tax each). I opened up one of the OMC reseal kits and it does come with instructions to reseal the cylinder. You will need a spanner wrench to remove the end cap of the trim cylinder to remove it and the inner rod to replace all the orings necessary.
I strongly suggest getting the cylinder repaired or replaced as soon as possible, if water is getting into the trim system due to the faulty seal, it may ultimately ruin the trim pump (expensive).
Read more:
http://www.justanswer.com/questions...-3-i-o-with-a-cobra-sx-outdrive#ixzz0lyIwGqCt