HOW TO: Replace Fuel Filter - NA Legacy L Sedan

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Manarius
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HOW TO: Replace Fuel Filter - NA Legacy L Sedan

Post by Manarius »

I know it seems kind of stupid for me to make a guide on how to replace the filter, but I'm going to anyways so no one will have the same problem I did.

Parts needed: Philips Head Screwdriver, Fuel Filter (FF739) - ~18 from Autozone, ratchet to undo negative terminal from battery

Time needed: 30 minutes (that's high, but gotta leave plenty of time)

Step One: Finding the damn fuel pump.

This step isn't too hard once you know where you're looking. Basically, you'll want to roll up the mat in your trunk to reveal the access hatch to the fuel pump.

Image

There are 4 phillips head screws there. The front two are easy. The back two may require you to rig up a way to unscrew them if you don't want to remove the rear seat.

Step Two: Relieving Fuel System Pressure

Disconnect the electrical plug from the top of the fuel pump. Then, hop in your car and make it turn over for about 5 seconds. If it starts up, just let it stall out (it will really quickly). Then, remove the negative lead from the battery.

Step Three: Finding the filter

This step is fairly easy. It's attached to the driver's side strut wall. I have it circled in the picture below.

Image

Step Four: Getting the filter out and replaced

Get out that trusty phillips head screw driver again and remove the clips that hold the lines to the filter tight. Be careful not to lose the nuts that make the clips stay tight. Once you've gotten that done, you'll need to get the tubes off. Using needle-nose pliers works very well for this, just as long as you don't beat the tubes too badly. They will take a little work to get off, but once you get them started they'll be easy. Note that when you take the tubes off, there might be a little bit of residual gas in the tubes so you might want a rag near by.

Now you have the tubes removed. Undo the clip that holds the filter to the wall and remove the filter carefully. Note the position of the plastic clip on the top that other fuel lines run through (It's like a guide thing to keep the tubes away from the engine). Once you have the filter out, be careful with it because it still has gas in it. Get out a can and pour the gas from the filter into the can. Make sure to do it through both tubes coming out of the filter just to get all of it out. Then, remove the rubber liner from around the old filter and put it on the new one.

Step Five: Reverse!

Once you have all that done, reverse the process. ATTACH THE TUBES TO THE CORRECT SIDES!!! The filter is marked with In and Out. The 'in' tube comes from the back of the car, while the 'out' tube goes straight into the manifold/intake/engine bit. Also, make sure to make the clasps tight on the tubes so that they don't go flying off or anything while you're driving. Reconnect the negative terminal and plug to the pump and you should be good to go. The car may take some extra time to start for the first time after replacing the filter, but after that, it shouldn't happen again.
Manarius wrote:The Neo-Cons would call me a defeatist. I'd call me a realist. I'm realistically saying that a snowball has better chances in the blazes of hell than democracy has in Iraq.
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Post by vrg3 »

Nice writeup. A couple of notes to add:

You don't have to get to the fuel pump access panel; the pump's wiring harness runs under the passenger side of the rear seat cushion, and there's a connector there. You can just undo the two 12mm-head bolts (on sedans -- I don't know wagons) holding the seat bottom cushion in, swing it up, and disconnect the connector.

The usual strategy to remove rubber hoses is to first twist them. If you can break the seizure and get them to rotate, they'll be much easier to pull off. I have also had some success using an open-ended wrench to push on the end of the hose.

Be really really careful using metal tools on hose, though. If you're using needle-nose pliers, at least put a rag or something between the pliers' jaws and the hose. They do make plastic hose-pinch pliers with rounded jaws that are much safer to use on fuel hose.

If you damage the hoses, or if they don't seem to be in good shape, they can be replaced with 5/16" SAE 30R9 fuel injection hose. Any auto parts store will at least carry short segments of it.It's definitely a lot easier to just cut the old hose off and replace it than to bother removing the hose intact.

If you find you have to replace a hose clamp, be sure to get another fuel injection clamp. Don't use a regular worm-drive clamp.

After getting everything buttoned up, turn the ignition to the ON position, wait about two seconds, and then turn it off for about five seconds. Repeat a few times. This will prime the system with fuel so you don't sit there cranking for a long time.

An OEM filter is Subaru part number 42072PA010. The Purolator filter is F54668. This is the same filter used on all Legacy, Impreza, SVX, Outback, Forester, and Baja models up through 2004.

And in case you lose (or didn't have!) any of the filter's mounting stuff, the bracket is part number 42050AA020, the strap is part number 42053AA000, and the rubber padding is part number 42031AA040.
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Post by Manarius »

I thought it was just a little easier to get at the panel and since I didn't know what to undo under the seat, I figured I'd go with what I knew I was dealing with.

The primering idea is a good one though. My crank time without priming was probably 3 or 4 seconds at max (my car starts like a flashlight).
Manarius wrote:The Neo-Cons would call me a defeatist. I'd call me a realist. I'm realistically saying that a snowball has better chances in the blazes of hell than democracy has in Iraq.
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Post by vrg3 »

Yeah, neither is really hard to access unless you have a lot of junk in the back seat or in the trunk.

The two bolts holding the seat cushion in are kind of right by where the passengers' calves would be. You can't miss them. Just undo both of them and the cushion will swing up (the only other thing holding it in is a little loop in the middle that attaches to a hook on the seat back).

Another good reason to prime the system is that it lets you do a preliminary leak check.
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Post by kleinkid »

I have replaced fuel filters on three of our Legacys and didn't disconnect any electrical component, including the battery. Was this a bad thing and if so why?
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Post by vrg3 »

It's just good practice to disable the car's electrical system whenever:

a) Fuel vapors are going to be floating around -- a spark could ignite those vapors.

or

b) You're going to be wrenching under the hood -- if a metal tool somehow touches the alternator post or the positive battery terminal, or anything else that's 'hot', it could cause a dangerous short-circuit if it's also touching or almost touching pretty much any other metal part of the car.

Both are happening in this case.
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Post by 206er »

IMHO it is well worth it to just be careful with the fuel hose and not replace it rather than cut it up. getting new stuff back on is more of a pain in the ass, so save the couple bucks and make it easier on yourself unless the line is showing its age.
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Post by IronMonkeyL255 »

I just cut my hose, since it was starting to slightly dry rot, and it looked like the hose was original......
Disclaimer: If anything I post is inaccurate, please correct me. I do not wish to add to the misinformation floating around on the internet.

That being said, everything I post is accurate to the best of my knowledge.

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Post by entirelyturbo »

Well, here's the thing about the hoses:

The outlet one going to the fuel pipe under the intake manifold is cake. But the inlet one going into the filter is a total pain in the balls, because it's in between the brake MC and the strut tower with about an inch of clearance.

So try to save the inlet one, unless it's damaged or leaking.
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Post by ultrasonic »

subyluvr2212 wrote:Well, here's the thing about the hoses:

The outlet one going to the fuel pipe under the intake manifold is cake. But the inlet one going into the filter is a total pain in the balls, because it's in between the brake MC and the strut tower with about an inch of clearance.

So try to save the inlet one, unless it's damaged or leaking.
True, it's tight getting to the inlet hard line. It's between the firewall, the shock tower, and the brake booster, and under the fuel return lines. I replaced both inlet and outlet rubber lines on my Legacy, but on my Impreza I cut off the one going between the filter and the fuel rail inlet. After getting rid of that one, the filter can more easily be rotated to get the inlet hose off without damaging it.

But, if they look old, worn, cracked, or otherwise damaged.... just put the effort in and replace them both. It's not THAT difficult.
-steve-

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Post by AWD_addict »

When I replaced my filter I just disconnected the battery beforehand. After letting it sit overnight there was no need to disconnect the fuel pump. The small amount of gas present could be absorbed by a paper towel.

The hoses are a pain, using pliers with a rag under them worked ok.
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Post by vrg3 »

Oh, also -- this writeup is applicable to all first-generation models, not just non-turbo L models. In fact, it should be the same procedure for all cars that use this filter (Legacy, Impreza, SVX, Outback, Forester, and Baja models up through 2004).
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Post by vrg3 »

Oh, and this is also good information to have anywhere you're talking about fuel injection hoses. These are the rules about how far to push the hose onto a pipe:

If the pipe has an extra ridge further up, push the hose all the way up to the ridge. If the pipe only has that one bead right at the very end, push the hose about 7/8" up the pipe. In either case, put the edge of the clamp a tenth of an inch past the bead at the end of the pipe. Refer to http://www.graphics.cornell.edu/~v/pics ... nstall.png for clarification.
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Post by jblair »

I did this today, and it was relatively simple. On wagons, you can just flip up the rear seat and the fuel pump connector will be under the black plastic protector thing. I relieved the fuel pressure, but I still had a lot of gas pouring/spraying out. I just used an empty water bottle to pour the gas into.
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