3.0 V6 BiTdi CGQB High Pressure Fuel Pump - Best way to clean fuel lines during HPFP replacement


Registered User

A friend owns a 2013 A6 BiTdi. Car recently began to hesitate under acceleration before picking up as normal. It was taken to local Audi specialist who said they believe it's the high pressure fuel pump. The car has done over a 140k miles on the original pump. They also found small traces of metal particles in the fuel tank (which they believe is the pump beginning to break down).

We spent a few days stripping the car down to remove the old pump (an a** of a job tbh). We plan on sending the injectors off to a local company for cleaning & testing. Before I install the new pump and build it all back up, I'd appreciate a couple pointers.
  1. What's the best way to flush out all the fuel lines (as well as clean the fuel tank) to get rid of any particles that may be lurking? My current plan is to get some fresh diesel and blow it through with a compressor from the HPFP side to the fuel tank, and try to do the same with the high pressure lines if possible.
  2. Can the fuel rails also be reliably cleaned in this way?
  3. The new pump does not have the adapter that the sprocket slides onto. What would the best tool to remove it from the old pump? The pullers I have aren't able to get underneath the adapter to pull it off
  4. And finally, if anyone has any other things that I should look out for when putting everything back together, I'd greatly appreciate the advice. My plan is to change the fuel filter, fill the tank with clean diesel and then run the low pressure pump for several minutes with VCDS.
Any help is much appreciated.