Working on a rebuild of a hydroboost system. I pulled the Spool Valve and found 2 cooper pieces in the cylinder. I am thinking it was supposed to be some sort of compression ring to limit fluid movement. I cannot seem to find any pictures showing it or part numbers for such a part. The only thing I have come across is a spiral snap ring in one diagram to maybe hold the spring back but no part number and it was not in the kit I ordered. I am thinking of hitting up the junk yard this weekend and pulling another one apart to see if I can find what it might have been. Any other ideas?