Subaru moved the fuel filter to the fuel tank for in 2005 for Legacy's, Outbacks and STI's. STI's got it easy though, it's very simple to remove the fuel filter and replace it with a piece of submersible hose. Legacy's on the other hand received a whole new bucket assembly that requires a lot of work to bypass. In 2008 Subaru moved WRX's and STI's to this same bucket setup.
Subaru claims that the fuel filter never has to be replaced, but anyone who has worked with cars knows that they should be replaced occasionally, especially outside of the US. Replacement fuel filters cost $75+ and take a lot of work to remove and replace. For this reason I stared looking to convert back to the engine bay fuel filter found in older Subaru's.
1 x $12 - 10" to 14" Plastic Corrugated Fuel Flex Hose, can get them at Auto Performance Engineering.
1 x $1 - 11.3mm Oetiker Clamp (Clamping range 9.6mm-11.3mm)
1 x $1 - 14mm Oetiker clamp (Clamping range 11.5-14.0mm)
1 x $10 - Engine bay fuel filter from WRX/FXT
1 x $8 - 5/16" Fuel injection hose
1 x $6-$20 - Pliers for Oetiker clamp (I used Click-R Type Pliers)
Total = $32 without pliers, next years fuel filter replacement $10...
It's always a good idea to buy a spare parts (I bought 3 hoses in different sizes and tested fitment with them all).
Exploded view of the fuel pump assembly
Fuel pump and filter without the tub
Fuel filter is inside of this plastic
I was trying to gracefully remove the plastic, but it didn't budge and had to be cut off. This fuel filter is from a car with 30k miles, look how dirty it is still.
Before I found out about the wonderful corrugated plastic hoses, I was gonna use submersible fuel injection hose ($20 a foot!). I drilled out the hole to accommodate for that hose. You will need to drill the hole out a bit to fit the corrugated plastic, but not this much.
Original idea was to use the 5/16" submersible fuel hose and attach it to the stock corrugated plastic hose. But I couldn't find a reliable way to clamp it on (no barbs on stock plastic end).
When I decided to just remove the stock fuel hose, I found that our fuel pumps are 5/16", but the nipple on top is actually 3/8".
I spent weeks looking for something that could work, even bought 3" of the submersible 3/8" hose. In the end, I used the connector from the factory corrugated plastic hose and heat gun to expand the 5/16" hose to be 3/8", Don't heat the flex joints!
Fuel pump end is 5/16", I dipped the hose into hot water to soften it enough to be able to slide it onto the pump easier. Once again don't heat the flex joints.
Had to cut the filter assembly a little more to clear the Oetiker clamp, after that fit perfectly
Update: Heatshrink the hose on this part and use an Oetiker clamp, regular fuel injection clamp didn't hold the fuel pressure.
Looks confusing eh?
The return drain hooks right back up no problem.
The fuel hose needs to fall in between the plastic bends or it wont clear the bucket, this is why a 12"+ hose is needed.
There needs to be space between the top and the hose, because the assembly compresses when you install it. This is where 15" hose was getting a little long, luckily I found space to move it around and not hit the roof.
Update: I switched to use Oetiker clamp, don't use fuel injection clamp it wont hold the fuel pressure.
Finally all together and somewhat fitting well
Continued in next post, with engine bay fuel filter install.