my peugeot 406 hdi keeps pressuring the woter top up bottle?

have you tried the coolant bleeder screws to bleed out any air locks in the system

Wolfman Jak
July 2008

your cylinder head is possibly warped or the block if you did NOT have them SKIMMED,
or hairline crack in the head that opens when engine is hot putting PRESSURE into the bottle.(have the head pressure tested) if pressure drops will need another head to cure problem.

wirecutterman
March 2008