This little tool is needed to replace the seals on SY accumulator control valve bobbin pistons.  Carefully remove the old seals with an X-acto knife, then the tapered tool can slip into place on the the short end of the piston.  The new seals can then slide into place with fingernail pressure - assuming you have strong nails.  In the final pic, the seal has not relaxed to it's final shape, but it will in just a few minutes.

We also have SY ACV rebuilding kits available under the "Parts" tab.

This tool is only for SY cars running RR363.