Fuel Pressure Regulator Valve -N276-, REMOVING AND INSTALLING: Installing
The Fuel Pressure Regulator Valve -N276- has a biting edge instead of a sealing ring and cannot be reused.
Check the new Fuel Pressure Regulator Valve -N276- sealing surface and threads for damage.
Check the sealing surface on the hole in the fuel rail.
Coat the biting edge of the threaded insert and the O-ring for the Fuel Pressure Regulator Valve -N276- with diesel fuel.
-- Tighten union nut by hand.
-- Align the check valve so that the connection line is not taut after connecting the connector.
-- Hold the check valve housing hex bolt in this position with pliers (for example, water pump pliers).
-- Tighten the union nut using the 30 mm Open End WrenchT10553 to do so counterhold on the housing hex fitting at the same time.
Tighten the Union Nut in 4 Steps.
| Stage | Tightening Specification |
|---|---|
| 1. | Install all the way in by hand. |
| 2. | Counterhold to 60 Nm at the housing hex bolt when doing this |
| 3. | Turn back 90° |
| 4. | Counterhold to 95 Nm at the housing hex bolt when doing this |
-- Tighten the banjo fitting with new seals.
Fuel System, Bleeding and Performing a Leak Test
-- After installing, let the engine run at a moderate speed for a few minutes and then stop it.
The high pressure connections must "not" be opened; the fuel system bleeds itself.
-- Check DTC memory and erase, if necessary.
-- Switch off ignition.
-- Carefully check the entire fuel system for leaks.
If there are leaks even though the correct tightening specification was used, replace the affected component.
Perform an adaptation after replacing the high pressure pump and/or the Fuel Pressure Regulator Valve -N276-. The procedures are also described in Guided Fault Finding.
-- Perform a road test where the accelerator pedal is pressed all the way down at least one time. Then check the high pressure area again for leaks.
If there is still air in the fuel system, the engine may switch to emergency mode during the road test. Turn off the engine and erase the DTC memory. Then continue the road test.
-- After the road test, check the DTC memory again.