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Injectors > < High-pressure pump - exploded view

A4 Mk3

Removing and installing high-pressure pump
Removing and installing high-pressure pump
  Note
t  The high-pressure pump must only be removed when the engine is cold.
t  When installing the high-pressure fuel pump, it is essential to ensure that no dirt enters the fuel system.
t  Use a cloth to catch escaping fuel.
t  Check O-ring on high-pressure fuel pump and renew if damaged.
t  Lubricate high-pressure fuel pipes lightly with engine oil and always ensure that pipes are free of tension when tightening the connections.
Removing
–  Remove engine cover panel.
  WARNING
Fuel system operates under high pressure. Always dissipate pressure in high-pressure section prior to opening fuel system. For procedure, refer to → Chapter
   
–  Detach electrical connector -2- from fuel pressure regulating valve -N276-.
–  Detach fuel lines -3, 4 and 5-.
  A24-11096
–  Unscrew retaining clip -arrow-.
  A24-11107
–  Remove bolts -arrows-.
–  Carefully pull out high-pressure pump. It is possible that the roller tappet may remain lodged in the vacuum pump.
Installing
–  Renew O-ring for high-pressure pump.
–  Before fitting, check roller tappet for damage and renew if necessary.
–  Fit roller tappet in vacuum pump, noting position of locating element.
  Note
t  The roller tappet must be positioned at the lowest point when installing the high-pressure pump.
t  If the old high-pressure pump is re-installed, or if a used pump is installed, the connecting piece for the fuel supply line (high-pressure section of the system) must be renewed. Refer to high-pressure pump - exploded view (item 9) → Chapter.
–  Turn crankshaft until roller tappet is positioned at lowest point.
–  Renew connecting piece at high-pressure pump.
–  Fit high-pressure pump in vacuum pump and secure in position.
–  Tighten bolts hand-tight.
l  Tightening torque: refer to exploded view of high-pressure pump → Chapter.
–  Now tighten bolts in diagonal sequence to specified torque, refer to high-pressure pump - exploded view → Chapter.
–  Fit both fuel lines and secure with spring-type clips.
–  Tighten union nut on fuel supply line hand-tight. Align so that line is free of tension and tighten to specified torque → Chapter.
  A24-11096
–  Re-attach electrical connector -2- for fuel pressure regulating valve -N276-.
  Note
Check fuel system for leaks.
  A24-11096

Injectors > < High-pressure pump - exploded view