Fuel filter upgrade

[Alec300SD]

Inspired by Diesel911, cho and others, I did a fuel filter upgrade on my 78 300SD and my 83 300SD.


Better fuel filtration, down to the two micron level, can be achieved using a CAT 1R-0750 fuel filter.
(Even better fuel filtration, down to the one micron level, can be had with a Nicktane 1 Micron 100% Synthetic Microglass Tall Fuel Filter from nicktane.com.)


My requirements for this upgrade for my vehicles:
1) Update to a “02” stock fuel filter head (6150920208).

2) A relocating plate (plus a spacer for cars with brackets attached to the original fuel filter head) and the mounting hardware needed to relocate the updated “02”
stock fuel filter head (6150920208) to allow the longer CAT 1R-7050 or Nicktane tall fuel filters to clear the lower webbing of the power steering bracket (6172360330).

3) A thread adapter (with central M14 X 1.5mm threads and with the correct external thread – to match the filter) is needed as well. The CAT filter has 1” X 14tpi threads.
The Nicktane tall filter has 1” X 12tpi threads.
This threaded adapter has to be custom made as there are none commercially available.

4) A crush washer (17mm X 23mm X 1.5mm) used between the threaded adapter and the updated “02” stock fuel filter head to protect the boss on the fuel filter head from damage.
(14mm X 23mm X 1.5mm would be ideal, but is not readily available)

5) The updated “02” head stock hollow fuel bolt uses two o-rings. I wanted to use Viton o-rings to be able to use biodiesel.
I used a 2.5mm X 14mm Viton o-ring for the top groove and a 2mm X 10mm Viton o-ring for the bottom groove of the hollow fuel bolt.

6) No modification of the stock “02” fuel filter head is needed when using the CAT 1R-7050 filter.

7) Some of the webbing on the Stock “02” fuel filter head must be removed to use the Nicktane fuel filter as it has a larger diameter than the stock filter.

8) New flexible clear hard lines need to be installed (6150704232, 6150704032, and 6150705632)

9) Also needed are two aluminum crush washers 14mm X 18mm X 1.5mm (007603014100) for the larger diameter fuel head inlet line, and 8 aluminum crush washers
12mm X 15.5mm X 1.5mm (007603124205) for the other two clear hard lines ( 12mm X 15.5mm X 1.5mm is an odd size, so 12mm X 16mm X 1.5mm would also work).

10) And of course, the upgraded fuel filter is needed as well: a CAT 1R-7050 to be used with the 1” X 14tpi adapter, or the larger diameter Nicktane filter to be used with the 1” X 12tpi adapter.