RX300 Fuel Pump Replacement

Intro: RX300 Fuel Pump Replacement

There is a prerequisite for this instructable - https://www.instructables.com/id/RX300-Removal-of-Back-Seats/

The fuel pump is located under the driver side back seat.  You will probably find that it is easier to have both back seats out of the car in order to flip the carpet forward out of the way while you work.  Also, it gives you an opportunity to clean while you have the tools out anyway.

Remove at least the driver side rear seat and flip the carpet forward out of the way.

STEP 1: Accessing the Top of the Pump

There is a large, 6" diameter cover with a wire harness coming out of it.  You will need to pry very gently, but firmly for a prolonged period of time.  The sealant will slowly release and the cover will let go.  Do not get this sealant material on any clothing you care about, it doesn't like to come off.

There is a short run of wire harness between the cover and the top of the pump.  Press the connector catch by squeezing with your thumb and gently wiggle and pull the connector off of the top of the pump.  The wire was too short to put my hand on it and show you how to do this, so the description will have to suffice.

Once the wire is disconnected, you can easily set the cover to the side.

STEP 2: The Invisible Fuel Line Clip

In the previous image on the last step, you will not be able to see this clip.  It was covered in road dust and took a minute to figure out what was holding the fuel line, I cleaned it and set it in its relative position for this photo. 

Simply use a small flat head screw driver to gently pry the clip out. 

Note: The clip has a little spring to it and it will shoot when it finally lets go.  Push a rag into the surrounding area so that you don't lose the clip.

STEP 3: Back Pressure Will Push Fuel Out the Top

With the clip removed, you can gently pull straight up on the line to remove it from the top of the pump.  However, don't do it yet.  First use a combination of #2 Phillips head screw driver and #8 box wrench to loosen the 8 screws that make up the retaining ring.  The ring will also be stuck on from age and vacuum in the tank.  I needed to pry a little at the edge to make it let go.  Looking back, I probably could have loosened the gas cap.

With the retaining ring loose, it is time to remove the fuel line - pull straight up gently.

My retaining ring did not fit through the hole.  I simply moved it to what is the bottom right corner in this photo and let it rest on top of the tank.  Next, lift the pump assembly out, being careful not to damage the attached hose, float and filter sock.

I couldn't do this and shoot a photo, so please look at the next step to see what it is you are extracting before you begin.

STEP 4: The Pump Assembly

I was not expecting this giant coffee can kind of assembly.

After turning the assembly so that it rests on its top, I used a small flat head screwdriver to loosen the clips on the cap holding the filter sock.  This is all fairly brittle, be gentle.  Do not bend or otherwise upset the float, this is your gas gage.

STEP 5: Removing the Assembly Top

Lay the assembly on its side and again use the flat head screwdriver to loosen the clips and remove the top as shown.  You will be able to release the directional wire clip from the top of the pump.

STEP 6: Removing the Pump

From here, you will grab the end of the pump with the strainer sock and gently twist back and forth as you pull away from the rest of the assembly.  The "O" ring gasket and pressure from fuel inside the device will hold on very tight.  Be patient, it will come out.

STEP 7: Final - Match New Part and Position Then Re-assemble

This should be pretty obvious now, but place the new part in a position matching the way the old one came out and begin re-assembly with the new part.

Note:  My replacement filter sock had a round elbow instead of a flat elbow.  I used side cutters to clip out material and make room for the new filter.  This also made a tight fit when placing the pump back in the car.  Everything works great in my case.  Reverse this process to finish the job.

Comments

[HotPepperGuy]

Thank you for this excellent writeup from the bottom of our hearts.

My mom passed away a few months ago. My dad's 22yo RX300 fuel pump died and he didn't want to spend anymore money to keep it running but hated to lose the vehicle because there were lots of memories and it was sentimental to him. Him and mom use to do a ton of road trips and put over 300k miles on it.

I offered to try to fix it for him and followed your instructions to the tee. I let him turn the key this evening, after replacing the pump, and SUCCESS! He was so grateful and there were tears of happiness.

Thank you, you have no idea how much we appreciate this.

[bhunter736]

I'm glad it was helpful. While your message made my day, I'm also very sorry for your loss. Sincerely, Brad

[Weezi2121]

May as well change the pickup screen filter and gas filter while you're here so you wont havevto it again. It's just a suggestion.

[Weezi2121]

If you like take a few shot with your phone so you know what it looks like and which hoses are connected to what cause unless your memory is good then easier to look at a picture.

[rlzzzman66]

I have all put back in correct wiring. Pump is working car still not starting. Now what

[bhunter736]

I'm just a home mechanic, but if it were me, I would remove a spark plug right after trying to start the car and smell for fuel to see if it is reaching the cylinder. If there isn't fuel, maybe the injectors are clogged or failing. If there is fuel, then something else may be going wrong, like the ignition system. My RX300 used to blow out an ignition coil about every year.