Valve assembly installation details on 163.128 models (628 series engine)
1. Valve assembly installation details on 163.128 models (628 series engine) are shown in the illustration, to which all references found in the text refer.
2. Remove the air distribution pipe (see Section Servicing air intake tract components).
3. Remove the fuel filter assembly with the support bracket (see Chapter Servicing air intake tract components).
4. Disconnect the electrical wiring from the fuel line pressure sensors (B4/6) and the pressure regulating valve (Y74).
5. Disconnect the fuel pressure lines (1, 2 and 3) - immediately plug the open ends of the disconnected lines/fittings, collect traces of spilled fuel.
6. Unscrew the hollow bolt (4) of the nipple connector (5).
Attention! Sealing rings must be replaced!
7. Remove the valve block (9) from the air tract distribution pipe, having first disconnected the return line (8) from it.
8. Installation is carried out in the reverse order - do not forget to replace the sealing elements (6, 7), start the engine and check the fuel system components for signs of leaks. Finally, clear the memory of the on-board diagnostic module (see Chapter Engine electrical systems).