Airtex E7181M In-tank Lift Pump

2005 Jeep Liberty CRD

Total time: 20 hours

For someone with more luck and skill it might take less time, but for me it took about 20 hours spread over 4 days. I'm sure it can be done in 19.

A big thanks to all the L.O.S.T. KJ contributors to these threads:

It's 10pm - where's your lift pump?

my jeep has factory wiring for a lift pump!

And especially: gmctd, dgeist, bill.barg, crdjon and ripster.


Parts List

In-tank Pump

So you want to buy a lift pump? Not so fast mister. There are (were) 3 to choose from:

  • Dodge 3500 Cummins 5143160AA
  • Airtex E7181M
  • Spectra Premium SP7181

I believe all 3 are discontinued awaiting a redesign from Dodge.

Some of the Cummins and the Airtexes might still be available. It took 7 weeks for my Airtex to get to me from Auto Parts Giant back in August 2008, but I only paid $131.71 delivered.

Wiring harness


Rewire existing

2006, 56047848AB ~ $52

2005, 56050284AB ~ $36



All-weather, cold-shrink tape This tape doesn't stick to anything but itself.
terminals (pins)

FCI Apex 2.8mm terminals from NTI. $25 minimum order.

54001800 (female) and 54001801 (male).

You'll need 2 female and one male pin. Hardly a $25 order, but consider ordering some of these high quality, weather tight connectors and parts to use elsewhere.

Order the extraction tool, too. Part 5400ext. For $5 it's one of the handiest tools I have. It's not made by FCI so you might be able to find it elsewhere as, White Products Div (J. R. Greenleaf & Co).

You can order with a credit card, but NTI requires a shipping account. (Easy to set one up for free at

1/4" x 1/2" Bolt w/ Washer & Lock Washer
Milk Crate
Who "buys" these?
You've got one already. Not an excuse to get the stainless steel one.

Step 0: Prep

  • Clean the underside of the carriage before starting. I wish I had.
  • Make sure your vehicle is safe to work under by reading and following all instructions that came with any lifts, jacks or ramps.

Step 1: Lift Up Rear Seat and Pull Up Carpet

Better pictures than I have can be found here from dgeist.

And a good slide show of the whole process from Bill.Barg here.

Under the soundproofing layer you will find the connector with the pump wire.

The relay and fuse were already installed at the factory.

Step 2: Unplug Connector

  1. Slide the red locking tab over.
  2. Depress the latch, and
  3. Pull apart.

Push the harness out through the floor pan.

Step 3: Disconnect Fuel Lines

First release the fuel lines from the fuel line hanger. I found this very hard to do even after I'd figured out the release mechanism. Basically you drive something to the left of the right-most opening in the top of the fitting. This will release the tab and allow you to pull the two halves apart.

But if the hanger was hard, I found the fuel line "quick disconnects" anything but quick. The tiny "button," flush with the connector, must be depressed fully as shown in this image.

Worse, they are rotated away from you under the chassis, so you have to feel around with your finger tip to locate them. This is hard to do on your back with big, fat, cold fingers and when the connectors are dirty. It took me near an hour to manage the two of them..

Step 4: Disconnect Vehicle Speed Sensor (VSS)

And any other connectors on your harness.

  • Slide red tab back fully..
  • Depress release tab fully.
  • Pull.

Step 5: Disconnect Fuel Filler Tube & Vent

I made the mistake of thinking the weight of the tank would pull the hose off the inlet. Not! Disconnect the inlet as soon as you can.

There is also a vent tube to disconnect. Below is a picture shot below and behind the left rear wheel well. As you can see, it's all open. The connector to undo is just out of view in the channel to the right.

Step 6: Release Tank Straps & Drop Fuel Tank

I have the factory tow package and I was able to undo the bolts without removing the hitch using a "wobble" extension on my socket wrench. I was also able to bend the straps to clear the bumper.

I supported the tank on two jacks (a cradle of some kind would be superior).

I then released only the rear bolts holding the straps on.

This allows the tank to "ride" down on the straps to the ground.

I made a number of mistakes:

  1. Too much fuel in the tank (about 8 gallons).
  2. Didn't release filler hose before trying to drop the tank. I thought the weight of the tank would pull the loosened hose right off, it didn't.
  3. I didn't undo the vent tube.


Step 7: Add Wires or Modify "Gasser" Harness

There seem to be 3 approaches to the wiring:

  1. Use the harness from a gas model Liberty and rearrange the pins. Here's a link to how to do that from gmctd.
  2. Pull the wires from the gasser harness and transplant them into the existing harness. Here are crdjons' pictures.
  3. Add two new wires.

I chose to simply add two new wires because I found a vendor for the connector (FCI Apex 2.8mm terminals available from NTI). I'd already ordered the harness, but I noticed it had an extra connector. Since it's a 2005, I also have the 5" problem. All-in-all I thought it would be easier to simply add the two wires to the existing harness.

This involves partial disassembly of the harness by removing the hangers and untaping the loom.

Below illustrates two things.

  • One, using a pick tool to release the binding on a wire hanger, and
  • Two, why one should wash the undercarriage first.


Here are the two ends of the harness rewired. I used 18 gauge wire; gray for hot and black for ground. As you can see, the 10-pin connector (right) is marked with pin #2 (the pump hot side). It goes to pin #4 on the 4-pin connector that connects to the tank.

The black ground wire terminates in the passenger area and does not use the 10-pin connector.

crdjon has excellent photos of how to add the wire here.

Bill.Barg here.

Ripster too here.

The Apex official instructions are here.

Rewired harness shown below.

Step 8: Reinstall Harness

You will need to connect the ground wire to the chassis. A ground point is provided. I tapped mine out to take a 1/4" fine thread bolt, but you could probably use a self-tapping screw. The metal is soft and I threaded it without cutting oil and only a pair of Vice Grips to hold the tap.

I added a quick disconnect because I didn't leave enough wire.

Step 9: Remove Old In-tank Unit & Swap Float Arms

Swapping floats will ensure your fuel gauge reads correctly.

Step 10: Modify Index Tab

While the tab issue has mostly revolved around the fuel level readings being correct, to me the bigger issue is keeping the same orientation so the pre-formed, plastic fuel lines aren't stressed or rub upon reinstall.

At left below is the new unit. I snipped off the area in red using wire cutters. This works, allowing precise alignment, but the tab is now smaller than the slot. When I hammered the retaining ring back in, it drifted counter clockwise.

Ideally it would help to somehow move the piece or otherwise restore the tab on the other side as shown in blue. Or reduce the size of the slot with epoxy putty or something. The solution to this part is left as an exercise for the reader.


Step 11: Install Lift Pump

The main problem here was that I couldn't get the retaining ring to rotate back into the second notch (i.e. compress the new o-ring).

The new unit came with a shiny new o-ring. I dutifully replaced the old green one, but as hard as I drove the ring with a hammer and screwdriver, I could not get it to seat back in the middle slot.

It is obvious that these rings are not set at the factory with a hammer and screwdriver, so I called the dealer to see if there was a special tool. Indeed there is and even on a Friday afternoon they would let me pop on over and compress the seal for me.

I drove over (did I mention not to start this project without having a spare car?) and after some discussion, because it's a diesel, shepherded me to a back garage. A diminutive older guy with a club foot eyed me wearily. He must be named "Crusty." I told him my problem. "Let's see what we can do," he said turning away and limping off to get what I imagined was the factory tool. I followed him to a tool chest where he slid open a lower drawer to reveal...hammers. Hammers! I almost burst out laughing. "We have the tool, but it doesn't work as well." He held up the hammer and out of no where a towering assistant appeared to take it. "Hammer the ring in for this gentleman would you Igor." [I made up the Igor part].

Well no matter how hard Igor hit the ring it wouldn't seat. They concluded the ring was too fat and suggested I use the old one. This I did and the ring seated with a few taps.

In hindsight I should probably have tried softening the new ring in warm water.

gmctd added....

The correct method of installing the clamp ring with a hammer and drift driver is to triangulate the thrust and parry, which keeps the ring centered: select any slot, tap it, then move to any of the other two slots at 120* angle from the first, alternating the hits between the three slots at 0°, 120°, 240°, 0°, etc, keeping the clamp centered in the tank ears and on the module - can also do 4 slots at 0°, 180°, 90°, 270°, 0°, etc - just takes a little more time - and, since these CRD KJ's are less than three years old, reusing the original gasket is a good option, making installation even easier - the Miller SPX #9340 tool is also easier, tho requiring two people, one to hold the tank, one to compress and manipulate the 1/2" drive break-over bar.


Step 12: Test Unit

Since I had too much fuel in the tank I used the new pump to pump it out. I was thus able to verify that the fuel gauge works correctly. It does. Even with the float misaligned, but float arms swapped.

Step 12: Reinstall Tank

It ain't pretty and it ain't fast...

This was tedious work. The more so because I thought I might break the plastic fuel lines, so I didn't put them on until the tank was half way up. A difficult task in tight space.

Reconnect and re-hang:: Filler Hose, Vent Hose, Fuel Lines, Fuel Pump, VSS.

Step 13: Prime System

  1. Turn key to the "ON" not "Start" then to "OFF". This initiates 20-seconds of pump time. You should hear it whirring away.
  2. Repeat.
  3. Check to see if there is any air to purge from the fuel filter head.
    • If yes, purge manually.
    • If no, start your engine

Step 14: Test Drive & Leak Check


It works and runs great. My motor used to go "takatakataka." Now it goes "tikatikatika." As other have also reported my FM reception is greatly improved and my bald spot is growing back in. A highly recommended mod.