The fuel system is a major component that potentially can cause a lot of problems. Only a portion of the fuel that runs through the fuel filtration system is burned in the engine. The remainder is used to cool the injectors and then is returned to the fuel tank. This is standard on all diesel engines. Fuel that sits for a period of time can produce algae which can block the fuel filter. Water can condensate into the fuel tank delivering water into the fuel system and so on. On this coach a 2000 Safari Continental with a CAT 3126B, 330hp engine the Racor-Winn 200200 (the Win system was installed prior to the CAT filter to remove water and other particles). This system was prone to air leaks.
On my coach I could not and did not want to remove the fuel tank to clean the tank. Therefore I installed a third additional filter to remove any debris before it reached the origonal fuel filter system. Additionally I wanted to be able to see the fuel flowing through the system. Now it is true that only the single CAT filter of 1 micron is needed but that in my case was inadequate for all the reasons listed above. I replaced the Racor-Winn system with the new Racor 790R30 system and an additional pre-filter system (Golden Rod) that could be manually cleaned. So the filtration fuel delivery sequence is: Golden Rod – (filters down to 40 micron and has a water separator), Racor 790R30 (100 micron pre-filter, 10 micron final filter, with water separator and electric fuel priming pump), CAT 1 micron primary filter.
Therefore the 100 micron filter in the Racor 790R30 is not being used because the first filter in-line removes material down to 40 microns; that is intentional. The disadvantage of the internal 100 micron filtration is that the Racor must be disassembled to check debris in the filter because it cannot be visually inspected. However the Golden rod shows the fuel flow and also has a removable, viewable, cleanable metal mesh screen.
Additionally two gauges were added, one to monitor the fuel vacuum to indicate if the Racor filter is being plugged and the second for the fuel pressure out of the last stage filter before the injectors. The engine service bay was redesigned to accommodate these changes.
There is an error in the project terminology used here related to CAT’s description of the primary filter system. CAT uses the term ‘primary filter’ as the final source of fuel to the engine, I used the term primary as related to the first filter in the system which used to be the Racor and is now the Golden Rod. It is intended to add a final addendum presentation to add further information and to align the terminology to that which CAT uses.