High Pressure Lines, Removing And Installing

WARNING: This page is about a different car, the 2015 Audi A7 Quattro and 2014 Audi A7 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Special Tools And Workshop Equipment Required

Torque Wrench 1331 Insert - Reversible Ratchet VAG 1331/1
Torque Wrench 1331 Insert - Open Jaw - 17 mm VAG 1331/6
Union Nut Socket T40055

Procedure

NOTE:

Check the sealing cones for deformities, cracks, damages, scratches or corrosion before reinstalling. Replace any damaged or corroded high pressure lines.

Check the line bores for deformities, narrowing or damage.

Make note of the installation position of the previous high pressure lines before reinstalling.

-- Remove any dirt from the sealing cone on the fuel rail.

-- Clean and dry the fuel line and the line head with engine or brake cleaner.

-- Coat the thread on the union nut with clean engine oil.

-- Hand-tighten the union nuts for the high-pressure lines evenly, making sure they are seated without tension.

Union Nuts 17 mm Socket on Fuel Rail:

Fig 1: SW 17 Union Nut At Fuel Rail, Torque Wrench VAG 1331 And SW 17 Socket VAG 1331/6

Courtesy of AUDI OF AMERICA, LLC

-- To tighten the high pressure lines, use the Torque Wrench 1331 5-50 Nm VAG 1331 with Torque Wrench 1331 Insert - Open Jaw - 17 mm VAG 1331/6.

17 mm Union Nuts on Fuel Injectors

Fig 2: VAG 1331 With Ratchet VAG 1331/1 And Socket 17 Mm T40055

Courtesy of AUDI OF AMERICA, LLC

-- To tighten the fuel injection lines, use the Torque Wrench 1331 5-50 Nm VAG 1331 with Torque Wrench 1331 Insert - Reversible Ratchet VAG 1331/1 and Union Nut Socket T40055.

Fuel System, Bleeding and Performing a Leak Test

-- Let the engine run a few minutes at idle without pressing the accelerator pedal and then stop the engine.

NOTE:

The high pressure connections must not be opened; the fuel system bleeds itself.

-- Switch off the ignition.

-- Carefully check the entire fuel system and the six return line connections for leaks.

If there are leaks even though the correct tightening specification was used, replace the affected component.

-- 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.

NOTE:

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.

-- Check the DTC memory after the road test.

Tightening Specifications

Refer to OVERVIEW - FUEL INJECTORS