In-Tank Fuel Filter Replacement

2003 Civic Fuel Pump Assembly
To zoom in, click on the photo.

My 2003 Civic (seventh generation) was running fine in 2014 at 143k miles. Its owner's manual says nothing about replacing the fuel filter. But the seventh generation Civic Chilton's manual says to replace the fuel filter every 60k miles, and a number of posts at report that Honda advises replacing the fuel filter every 100k miles or when fuel pressure is low. I bought a new Beck Arnley fuel pump filter and an ImportDirect strainer sock for $35 on Ebay and for $7 at O'Reilly's, respectively. I used the following to help me replace my Civic's fuel filter:
Below are hints and discussion of problems I had. Thanks to jackoncruzpr at the site for some of the photos.

1. Gas Tank Almost Empty or Nearly Full?
I tried both ways. I think this job is much easier when the fuel tank is about 3/4 full or nearly full of gas. This is because, when you proceed to re-install the pump assembly, it primes better by being as submerged as possible. The level of the gas in the tank when nearly full is still a few inches beneath the access hatch underneath the back seat. Gas does not go everywhere.

2. Unscrewing the Large Locking Collar
The large locking collar (a.k.a. "lockring" and "locknut") holding the fuel pump/filter assembly down is a challenge to get off using a hammer and chisel. Instead I borrowed the tool contained in Autozone's OEM #27160 "Fuel Pump Replacement Kit" pictured below. See also

3. Removing the Fuel Pump Assembly
Once the locking collar on top of the fuel tank is off, I found rotating the fuel pump assembly 180 degrees and tilting it appropriately up and aft was the easiest way to remove the assembly. Remember that normally the float is on the aft passenger side of the assembly. When the assembly is rotated half a turn, the float is on the fwd driver's side.

4. Fastening the Tiny Steel Lock Washer
When re-assembling, at first I could not get the tiny steel lock washer that goes on the suction end of the pump to hold well, due to lack of clearance.
I ended up putting the pump into a vise, pushing on (a) the pump electrical connector (unplugged, at the discharge end) and (b) the rubber mounting/suction piping on the suction end to get the needed clearance. Specifically: Remove the top cover of the pump's plastic box. Take photos of the pump resting in its plastic box so you can get everything back together right:

Remove the pump from the plastic box. Disconnect the electrical plug and the pump discharge line, including the discharge El fitting. You will find a third O-ring at the pump discharge El. Do not lose it. Put the pump in a vise as shown below. The green arrows show where you want the vise to push. The red arrow is where not to push. Click on the photo to zoom in.
Carefully tighten the vise. Make sure the vise is pushing against the (unplugged) electrical connector on the one end and on the rubber mounting/pump suction piping at the other end. Again, do not push against the plastic pump discharge. Loosen the vise and rotate the pump appropriately. Retighten the vise. Repeat as needed to get the strainer/shock absorber to stay straight and achieve enough clearance to get the lock washer on. Do not apply so much force that you break the electrical connector or anything else. Put the tiny lock washer in place. Reassemble all. Re-using the O-ring at the pump discharge is fine.

At one point I also bent the lock washer tabs and washer body a bit so the washer gripped the nub on the end of the pump well.

5. Installing the Large Locking Collar
After putting the pump assembly back in the tank, getting the large plastic locking collar to engage its threads was difficult. If possible, get the tool above. Also (a) Examine the collar and male side threads to see where they start. Line up the female and male sides' starting points so you will hopefully feel engaging of the threads early on. (b) Before you put the assembly back in the tank, try to screw the locking collar back in place, so you know what it feels like when it catches. (c) Use a little liquid soap on the threads. (d) Have a friend hold down the pump assembly. Buoyancy is pushing against you when you install this locking collar. If you do not have the special tool above, then I think three strong hands are needed. I did not weigh enough to put my weight on the assembly and make this easy. (e) Even at the start of installation, the collar is hard to turn by hand. If you do not have the Autozone lender tool, you will need the hammer and chisel even for the early torquing. (f) Count the threads before starting. About three revolutions are needed. The factory service manual page linked above specifies 69 ft-lbf of torque.

6. Your Civic Does Not Start
If you go to start your Civic and all your Civic does is crank without catching, chances are good that the only problem is that one of the three O-ringed connections is not fastened correctly. The three O-ringed connections you want to check are: (1) In the El fitting that connects directly to the pump discharge. (2) Just downstream of the El fitting, where the new fuel filter hose connects to the El. (3) At the inlet to the pressure regulator. After I put everything back together the first time, my Civic did this -- cranked but did not start. My Civic's fuel pump could be heard whirring when my ignition key was in the ACC position, so the pump was rotating. I spent a few days figuring out why my fuel line would not pressurize. It turned out that the fuel pump discharge El was not correctly fastened. What happened: Getting enough clearance to make the tiny lock washer at the suction end of the pump stay in place had been difficult. To get the clearance, I had put the pump in a vise, but I had the vise set to push against the plastic pump discharge while the discharge's O-ringed fuel line El was still connected. The vise pushed the O-ring in the discharge El out of position. The red hexagon and red arrow below show where I had the vise pushing, by mistake. Red means wrong. To zoom in, click on the photo.

7. Will Something Break?

I found that breaking something during this repair is unlikely. The plastic parts, the fuel pressure regulator, the fuel level float and sending unit, and the pump itself seem pretty durable and forgiving. What is common though is incorrectly fastening the three O-ringed connections. The O-ringed female connectors have to go on straight. They should snug up against their respective male fittings. The connectors' clips should snap (more or less) into their correct positions.

8. Did the Fuel Pressure Regulator Break?
Probably not. I had the fuel pressure regulator in a vise, again tightening one of the O-ringed connections, and dented the regulator a little. It seems to work fine. As a quick check when you have the fuel pump assembly apart, you can wipe off the gas from the fuel pressure regulator's inlet connection (the connection that normally has an O-ring on it), put a rag on the inlet, and blow. You should feel none to little air coming from the outlet.

9. What If I Think I Broke My Fuel Pump?
At one point I thought I had broken my Civic's fuel pump. This was because there was no pressure in the discharge fuel line on top of the filter. I decided to bench test the fuel pump so at least I knew it was not the cause of the no pressure. A fuel pump bench test is dangerous and not something a novice should attempt. A spark near gasoline can cause an explosion or fire. I emptied the pump of gas and set it upright in a plastic bucket with a good lid. I alligator clipped the appropriate gage wire to my car battery's terminals, put a switch in the negative line, and used an appropriate electrical connector to connect to the pump's + and - terminals. Using a proper electrical switch avoids a spark while turning power on and off to the pump. You can run the pump a few seconds without any gas in the pump, and the pump will be fine. With only air running through the pump, I could feel pressure at the discharge end of the pump. I then took a cardboard beverage cup with about a half cup of gas in it and set the pump in it, suction side down, so the bottom third of the pump was submerged but the pump leaned at an angle. I put the pump and cup in the bucket and put the lid on. Turning on power to the pump for a second resulted in my hearing the pump discharging gasoline against the lid. Also after turning off power to the pump and taking the lid off, I saw the lid was soaked on the underside. The pump was and remains fine.

Factory Manual Excerpts