13 53 170 Replacing All Pressure Lines

13 53 170 Removing and Installing/Replacing All Pressure Lines (N74)

Special tools required:







WARNING:
Electric fuel pump starts up automatically when door is opened.
Disconnect battery negative terminal (risk of fire due to short-circuiting on removal).
Observe warning on cylinder head cover.







WARNING:
Carry out installation work on fuel system only with coolant temperature below 40 °C.
Wear full face guard and protective gloves.
Fuel can emerge spontaneously at high velocity when the high-pressure line is released.







IMPORTANT:
Adhere to conditions of absolute cleanliness when working on the high-pressure fuel system.
Introduced contaminants can cause malfunctions in the system.
- Do not allow any dirt particles or foreign bodies to get into the system.
- Remove all traces of dirt before removing pipes or individual components.
- Use only fluff-free cloths.
- Seal all fuel system openings with protective caps or plugs 32 1 270.







Recycling:
Fuel escapes when fuel lines are detached.
Catch and dispose of escaping fuel in a suitable container.
Observe country-specific waste-disposal regulations.







NOTE:
- Ignition coils must not be wetted with fuel.
The resistance of the silicone material is reduced significantly by contact with fuel, which may cause the ignition coil to fail
Cloths/rags must therefore be used to prevent fuel from getting into the spark plug slots

- Before installing ignition coils, clean spark plug slots with compressed air.
- Make sure the spark plug slot is absolutely clean.


Necessary preliminary tasks:
- Remove ignition coils
- Remove intake plenum







Clamp off fuel delivery line. Seal off fuel lines with special tools (1) 13 5 160 and (2) 13 5 162.
Catch and dispose of escaping fuel.







Removing high-pressure fuel line from injector to rail

NOTE:
The following description applies to all pressure lines.
First release pressure line on rail to reduce existing fuel pressure if necessary. Fuel must not get into the spark plug slot. Then release pressure line on injector.

Release union nuts (1).
Disconnect pressure line (2).
Set down pressure lines in order.







Secure injector against twisting with wrench (2).
Release union nut (1).

IMPORTANT:
If several pressure lines are removed, ensure that each pressure line is reinstalled in its original location (cylinder).
Mark pressure lines.







Installation:
Only if injector has to be rotated in fitted position:
- Release bolt (3) a few turns until holding-down element is slackened.
- Turn injector (1) in direction of arrow until union nuts (2) on pressure line can be easily screwed on by hand.
- To do so, engage wrench on hexagon head of injector if necessary.
- Tighten down union nut (2) of pressure line hand-tight.
- Tighten down screw on holding-down element (3).
Tightening torque 13 53 5AZ.

IMPORTANT:
Do not under any circumstances pull injector out of bore.
If the injector is pulled out of the bore hole, the PTFE sealing ring must be replaced. Replacing PTFE sealing ring, refer to 13 53 315.

Adhere to tightening sequence:
- First tighten down union nut on injector.
- Then tighten down union nut on rail.







Tighten high-pressure fuel lines with special tool 13 0 160.
Tighten high-pressure fuel line on injector with torque wrench (2) and special tool (1) 13 0 161. In so doing, grip hexagon head of injector with wrench (3).
Tighten union nuts with special tool (1) 13 0 161.
Tightening torque 13 53 2AZ.

Installation:
When tightening high-pressure line on rail, note that angle of rotation of special tool 13 0 161 is limited. Re-position special tool if necessary.
Distortion of torque possible.







Assemble engine.
Vent fuel system with BMW diagnosis system.
Check fuel system for leaks.
Check function of DME.