Fuel Rail: Service and Repair

Replacing complete injection pipe (M52TU)


Turn off ignition.







Remove microfilter.
Open cable duct on lower section of microfilter housing (2) and feed out cable(s).
Release screws (1) and remove lower section of microfilter housing (2).







Remove cover from fuel injectors. Unclip screw caps and release screws.







Detach low pressure hose (1) from pressure regulating valve.
Disconnect plug connection for intake air temperature sensor (2).
Detach terminal strip (3) for fuel injectors.







CAUTION!
Mark plug connections (1) of Lambda monitor sensors for cylinder group 1-3 and cylinder group 4-6 to avoid mix-ups during subsequent installation.
Unclip plug connections (1) from retainers and disconnect.
Remove retainers for plug connections (1) from injection block.







CAUTION!
Fuel in fuel lines is under pressure (approx. 3 - 5 bar).
Catch and dispose of fuel as it escapes.


Mark fuel lines (2 and 3) to prevent the fuel feed and return lines from being mixed up when they are installed later.
Unlock fuel lines (2 and 3) at rear of cylinder head.

Installation:
Check sealing rings in fuel hoses and sealing face on fuel lines for damage, replace components if necessary.
Before installing fuel hose, coat sealing rings with anti-friction agent.







Release screws (1) and remove injection pipe with fuel injectors.

Installation:
Coat sealing rings of fuel injectors with anti-friction agent to facilitate installation of the fuel injector block.