JIMS "ON BIKE" VALVE SPRING COMPRESSOR FOR MILWAUKEE EIGHTIt has always been necessary to remove the cylinder head from the engine when changing valve springs or valve seals. This tool eliminates this step. Just simply remove the rocker box and rocker arms, and install this tool on the rocker arm shaft. Then fill the cylinder with compressed air and you can easily rotate the tool and compress the top collar of the valve spring exposing the keepers to remove the top collar, valve spring and seal. A true time