I repaired the reservoirs by putting a bead of Seal-All around the base where the cracks were. Before the sealant set I used a vacuum pump to introduce a vacuum into the reservoir to hopefully pull the sealant into the crack. I then strengthened the sector beside the mounting pin, where the leaks were, with Sugru (I love yellow on a Boxster...). Both reservoirs now hold vacuum and may just be stronger than new ones.
