This is an easy project, and one that I'd put off for way too long before doing for the first time recently. Personally, I'd recommend changing your fuel filter at the same time you do your timing belt - every 90K miles or so - just as preventative maintenance, and to keep your fuel pump and engine running as smoothly as possible. Of course, if you're in a very dusty environment, every 30K may be a better interval.
The process is straight forward - remove the old filter and replace it with a new one - but there is one nuance worth mentioning.
The Toyota FSM recommends disconnecting the fuel pump, running the truck until the engine stalls (due to lack of fuel) and then removing the filter. This releases the pressure in the fuel lines prior to disconnection. I have found this to be unnecessary. Instead, I carefully disconnect the lines from the filter and allow the fuel to leak out into a catch basin.
If you do decide to disconnect the fuel pump, it's easier to do on the 4Runner than the Tacoma, but both can be done without lowering the gas tank, and the steps are covered below.
The only part you'll need for this is a new Toyota Fuel Filter. While nearly the same on 1st gen Tacomas and 3rd gen 4Runners, the brackets are different, so you'll want to make sure you get the appropriate filter:
As with the parts, you won't need many tools for this project either.
- 14mm flare nut wrench (this is a good set) - for the two flare nut fittings on the fuel lines
- 19mm open end wrench (this is a good set) - to hold the fuel filter steady while loosening/tightening the flare nuts
- 10mm socket (deep preferred) (good set) - to remove the nuts securing the fuel filter to the truck
Doing the Work
With the parts and tools in hand, let's get to it.
Disconnecting the Fuel Pump (optional, I'd recommend skipping this)
If you plan to disconnect the fuel pump, now is the time to do it. On a Tacoma, the connector/plug for the fuel pump is located on the top of the tank, near the front of the tank.
- From below the truck look over the top of the fuel tank just in front of the fuel tank filler neck and you will see the connector.
- Using your hand - or if your hand won't work, a pair of 90° needle nose pliers - to depress the clip holding the connector to the tank. Note: the tab you need to depress faces the right (passenger) side of the truck.
- With the connector clip depressed, separate the two halves of the connector.
- There's plenty of room to get your hand in the there and maybe you could depress the power plug with just your finger and be able to remove the plug.
On a 4Runner, the process is easier.
- Open the driver side rear door.
- Fold the rear seat bottom forward.
- Remove the two philips screws that secure the rear door threshold trim, and then remove the trim.
- Pull the carpet and carpet pad forward to reveal a small cap under the driver side rear passenger seat.
- Remove the three (3) philips screws securing the cap.
- Disconnect the fuel pump connector using a pair of needle nose pliers.
Removing the old fuel filter
- Using a 10mm socket, completely remove the nuts that secure the fuel line to the underside of the vehicle. Remove three (3) to the rear of the filter, and two (2) in front of the filter. Note: this will make the fuel lines more flexible, which will assist in removing the filter.
- Using the 14mm flare nut wrench on the fuel line nut, and the 19mm open end wrench to provide back-pressure on the fuel filter, loosen the forward and rear flare nuts that secure the fuel lines to the fuel filter. Note: only loosen these nuts, do not remove them completely.
- Using a 10mm socket, completely remove the two nuts securing the fuel filter to the truck.
- Using the 14mm flare nut wrench, loosen the flare nuts on the front and rear of the fuel filter until gasoline starts leaking out of the connections. Carefully continue to loosen and allow fuel to drain, until no more fuel is draining from the filter.
- Back the flare nuts completely out of the fuel filter, and remove the fuel filter from the lines. Note: this is where having flexibility in the lines can be helpful.
Installing the new fuel filter
- Orient the new fuel filter in the same orientation as the old.
- Insert the rear fuel line into the rear of the fuel filter, then the front line into the front of the fuel filter. Note: Do not start threading the flare nuts yet.
- Ensure that the fuel filter bracket fits over the mounting studs, and start the two 10mm nuts onto the studs to hold the fuel filter in place. Note: Do not tighten these nuts yet.
- Using your fingers, start threading the flare nuts into the fuel filter. Tighten until finger tight. Note: you may need to wiggle the filter and/or lines at this point to get the thread alignment correct. Be careful to not cross-thread these connections.
- Using a 10mm socket, replace the five (5) 10mm nuts that were removed to loosen the fuel lines in front and rear of the fuel filter. Tighten snugly.
- Using a 10mm socket, tighten the two (2) nuts that secure the fuel filter bracket snugly.
- Using the 14mm flare nut wrench and 19mm open end wrench, tighten the fuel lines to the filter. Torque to 21 ft-lbs.
Checking for leaks
After you have completed your work, start the truck and immediately check for leaks where the fuel line connects to the filter. If you have any leak at all, immediately turn off the truck and tighten the connections until no leaks are present. Be careful not to over-tighten here, as it is easy to strip the threads.
And that's it - you've now got clean fuel headed from your tank to the engine! Good Job!