I just reinstalled the engine in my 1995 chevy k1500 work truck. On the bottom of the slave cylinder was a hex head screw. I took it out and pushedthe rod back far enough that I could now get the cylinder bolted in place on the bell housing. When I put the screw back in it does not tighten. Goes flush with cylinder case then keeps on turning in place. Is this normal? I would think it would leak.