Yes will do cause the rubber seal is stopping it, need to: If youve no brake building grease (castrol red) then use brake fluid to lubricate everything inc rubber and piston Take piston out, take seal out (remember which way round it goes) Pull just part of seal that goes into piston ring groove onto the wrong end of piston (the threaded end) Now offer the piston upto the thread The other half of seal should be hanging off the piston skirt Before screwing the piston in carefully locate the remaining part of seal into the calliper groove So now the inner circle of seal should be streached over piston and the outter circle should be located in its calliper groove Now can start to wind the piston slowley in makking sure not to twist or tear the seal ad it slides along the piston Once Youve wound the piston almost all way in the inner part of the seal thats been sliding up the piston should fall into its correct groove on piston If you managed to follow this successfully head to nearest bar and drink heavely....oh forgot to mention....unless youve clamped the brake line all the while fluid will be slowley filling up the piston hole, so open the bleed valve
