Hello . I'm having a go at replacing the head seal O-ring ( in situ ) on my 300tdi Defender . I'm at the stage where I'm ready to loosen the bolts to allow the head to move back just enough to allow access to the O-ring . To prevent a shim in the pump from falling out of place the pump should be "on cam" to keep the pressure on it . In a YouTube video they have the top of the pump off so they can see that everything is up tight . Is there any other way I can ensure the pump is on cam without pulling the top off the pump ? Any advice would be great , thanks .
