Hello fellow MercedesShop.com members...

I am currently replacing all six sets of both the black rubber o-rings and the copper "crush washer” seals in the diesel Injection Pump of my 1999 Mercedes-Benz E300 TURBODIESEL sedan. I have chosen NOT to replace any of the six original Compression Springs, at this time, because the new Springs (M-B part no. 001-074-34-93) I had ordered from the Mercedes-Benz dealership are shorter than the original Springs that came out of the Injection Pump.

Although I have been very careful to keep the work area meticulously clean (with both Carburetor Cleaner and Canned Air) and have only removed and worked on one Pressure Valve Holder at a time, I have noticed that, upon the removal of the Pump's Pressure Valve Holder assemblies, pieces of the original black rubber o-rings as well as fine metal thread particles have fallen into the holes of the Injection Pump that were exposed when the Pressure Valve Holders were removed. Primarily, this was caused when the original, deteriorating o-rings were stuck around the treaded part of the Pressure Valve Holders during the disassembly process. When ratcheting out each of the six Pressure Valve Holders with the Special Splined 1/2" Drive HAZET Socket, pieces of the failed and deteriorated rubber o-rings and fine small metal particles (from the threads of the Pressure Valve Holders themselves) rained down into the area where the Pressure Valves and Pressure Valve Carriers are held.

My question is concerning the possible contamination of the diesel Injection Pump. If these debris particles are forwarded along the fuel delivery valves through the injection lines (once reconnected and the car’s engine started), may these debris particles eventually find themselves imbedded in the fuel injectors? I've read earlier threads mentioning that the diesel injectors themselves are VERY expensive and replacing them, due to blockage and contamination problems, could be quite expensive. Therefore, the need to keep everything clean during the replacement process is paramount!

I was thinking about the possibility of flushing out or purging the pump BEFORE reconnecting the metal fuel lines that lead to the injectors. The only problem I have is how? And how effective would this process be? As all six Pressure Valve Holders have a VERY small and deep pin-like opening at the top (where the fuel lines attach).

I was also considering the possibility of placing clean rags over all six of the open Pump's Delivery Valves (without reconnecting the metal fuel lines), once all six seals have been replaced and each of the Pressure Valve Holders have been torqued down to the final 35 Nm value. Another idea I had was to attach six tightly fitting hoses to the threaded top portion of each of the open six Pressure Valve Holders. I would simply have all six hoses empty into a bucket when I "dry crank" the engine. In theory, any debris contained in the six Delivery Valves would simply be ejected and flushed out through the hoses (with fresh diesel fuel entering the Injection Pump) by the turning of the engine, which in turn rotates the Injection Pump. Even though the engine would not receive any fuel (during this process), would the turning over of the engine create enough pressure to evacuate any contaminated particles from the diesel Injection Pump’s Delivery Valves?

Thank you for reading my new thread, as I would really appreciate hearing feedback from some of the more experienced diesel experts on this!

Attached Thumbnails