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View Full Version : D1 Fuel Filter (possibly RRC too...)



Tom109
03-16-2008, 11:34 AM
Ok, the fuel filter arrangement on the D1 has it's +'s and -'s, we all know that. So, I figured I try and come up with an alternative to make changes a little easier. I've been running an alternative filter for a few weeks and many tanks of fuel, so I can confirm that it is compatible with most brands of gasoline. (That's a joke BTW...)

The standard replacement filter is NAPA 3481. This uses the stock threaded fittings that tend to seize, or become difficult to remove (no application of heat here!). I found that NAPA 3484 is the 'same' filter element, with tubes on each end, and special connections that are not compatible with the D1.
http://www.series2forum.co.uk/Gallery/albums/userpics/10036/D1_filter3.jpg

In order to use the 3484, you need to do a few modifications, both to the truck plumbing and filter tubes. Since the stock filter uses filter-fittings crimped to rubber flex lines, which are in turn crimped to the hard lines, you need to cut the rubber flex lines between the stock filter and hard lines. The hard lines do have barbs under the metal crimps, so you'll now need to carefully cut back the metal crimped sleeve that secures the rubber line to the hard line. It seem like this would be difficult, but the metal is soft and easily cut with diagonal cutters. Just make sure you do not nick/scratch the hard lines.

Below, you can see the 3484 tubes (w/ a plastic connector cut-off) above the stock fitting with the metal crimps removed. (Notice the rust on the stock fitting, after 15k miles!)
http://www.series2forum.co.uk/Gallery/albums/userpics/10036/D1_Filter1.jpg

I had originally planned to re-use my stock fittings with a new filter, but one fitting was fused to the old filter and I could not remove it (even in a vice with heat!). Finding the 3484 seemed like a good option - except for the special connector and smooth tubing. The connector is plastic and simple to snip off. Next I added a simple flare to the end of the tubing to provide a shoulder for the clamp (preventing the clamped hose from working it's way off over time, pressure...) The tubes are quite hard, so I annealed them to allow my flaring tool to get a grip, and prevent splitting the tubes while flaring. The picture below shows the flared tube above the stock fitting.
http://www.series2forum.co.uk/Gallery/albums/userpics/10036/D1_filter2.jpg

Once you have both the entry and exit tube flared, you can move on to the installation. I used appropriately rated fuel hose, and fuel-injection clamps. These clamps provide a better clamping than conventional hose clamps (we are dealing with fuel here!). Be sure to do a triple-check on clamp/rubber-line/hard-line integrity. You can turn the ignition key to the 2nd position and run the fuel pump up to pressure without staring the engine.

I'll didn't get an installed photo, but aside from the clamps, it looks like the old one. Any questions let me know...

Tom P.