2008 Chrysler Aspen Fuel Pump Removal: A Complete Step-by-Step Guide
The bottom line up front: Removing the fuel pump from a 2008 Chrysler Aspen is a job you can handle at home, but it requires dropping the fuel tank because there is no access hatch under the rear seat. The entire process—from draining the tank to reinstalling the new pump—typically takes two to four hours for a DIY mechanic, and you will need a special lock ring tool to get the job done safely. If your fuel gauge is acting backward (reads empty when full and climbs as you drive), the problem is almost certainly the fuel level sending unit attached to the pump module, not the pump itself.
Before you start turning wrenches, understand what you are dealing with. The 2008 Chrysler Aspen with the 5.7L Hemi V8 uses an electric fuel pump module located inside the fuel tank. There is no service panel cut into the floor under the rear seat, which means you cannot reach the pump from inside the cabin. That leaves you with one option: lower the tank from underneath the vehicle. This guide walks you through the removal and replacement process from start to finish, including the tools you need, the safety steps you cannot skip, and the common mistakes that cause people to end up with a broken lock ring or a leaky fuel system.
1. Know What You Are Getting Into Before You Start
The 2008 Aspen shares its platform with the Dodge Durango, so if you have ever worked on a Durango of the same generation, the process will feel familiar. The fuel pump module is a single assembly that includes the electric pump, the fuel level sending unit, the strainer, and the housing. You cannot just pull the pump out and leave the sending unit behind—they are integrated into one unit that mounts into the top of the fuel tank.
Here is what makes this job harder than it looks:
1. The lock ring. The fuel pump module is held in place by a large metal lock ring. This ring is notoriously difficult to break loose. A hammer and screwdriver will not cut it—you risk bending the ring or damaging the tank flange. You need the proper lock ring remover/installer tool (Chrysler special tool 9340) and a 1/2-inch drive breaker bar.
2. The tank drop. Because there is no access hatch, you have to drain the fuel and lower the tank. A full tank of gas weighs close to 150 pounds, and wrestling it down while balancing on jack stands is not a one-person job. Get a helper if you can.
3. The float arm. When you pull the module out of the tank, the float arm is easy to bend. If you bend it during removal, the installation will still go in fine, but your fuel gauge will read wrong from that point on.
If all of this sounds like more than you want to take on, that is a reasonable call. Professional replacement runs about $965 at a shop, with labor around $301 and parts around $236. But if you are comfortable working under your vehicle and following torque specs, doing it yourself will save you several hundred dollars.
2. Tools and Parts You Will Need
You do not need a full shop to pull this off, but you do need the right stuff. Gather everything before you jack the vehicle up so you are not running to the parts store halfway through.
Tools:
1. Lock ring remover/installer tool 9340 (or an equivalent universal lock ring tool)
2. 1/2-inch drive breaker bar (at least 24 inches long)
3. Floor jack and two jack stands (rated for at least 3 tons)
4. Fuel line disconnect tool (for quick-connect fittings)
5. Drain pan or approved fuel storage container (5-gallon minimum)
6. Socket set with extensions (10mm, 13mm, 15mm, 17mm)
7. Flathead screwdriver and trim removal tool
8. Rubber mallet
9. Shop rags and a fire extinguisher
10. Penetrating oil (PB Blaster or similar)
Parts:
1. New fuel pump module assembly (OE part numbers 68027988AC, 68027993AA, 68027993AB, or 68027993AC—these are the factory references for the 2008 model year)
2. New fuel pump gasket/O-ring (Mopar part 68304753AA, which replaces the older 57009306AA)
3. Fuel filter (if your vehicle has an external in-line filter, replace it while you are in there)
Do not buy a cheap no-name pump. The factory pump runs at 40–60 psi, and a subpar replacement may not hold that pressure, which leads to hard starts and hesitation. Stick with a known brand like Bosch, DriveMotive, or an OEM Mopar unit.
3. Safety First: Relieve Pressure and Disconnect Power
Fuel system work is dangerous if you skip the basics. Gasoline ignites easily, and a fuel line full of pressure will spray fuel everywhere if you disconnect it carelessly.
Step 1: Relieve fuel system pressure. Locate the fuel pump fuse or relay in the fuse box (under the hood or under the dash). Pull it out, then crank the engine. It will start and run for a few seconds, then stall when the fuel pressure drops. Crank it two or three more times to confirm no pressure remains in the lines.
Step 2: Disconnect the negative battery cable. This is not optional. You are working near electrical connectors and fuel, and a spark from a powered circuit can ignite gasoline vapors. Disconnect the negative terminal and tuck it out of the way so it cannot accidentally touch the battery post.
Step 3: Work in a ventilated area. If you are in a garage, open the doors. Have a fire extinguisher rated for fuel fires within arm's reach. Do not smoke, and do not use any open-flame tools nearby.
4. Accessing the Fuel Tank: Drain and Lower
Since there is no access hatch, the only way in is from underneath. Here is how to get the tank down without damaging it or yourself.
Step 1: Jack up the rear of the vehicle. Place jack stands under the frame rails near the rear axle. The tank sits ahead of the rear axle, so you want the rear of the vehicle high enough to work under comfortably—18 to 24 inches of clearance is ideal.
Step 2: Drain the fuel tank. Use a siphon pump to remove as much fuel as possible through the filler neck. You do not have to get every drop out—a few gallons left in the tank is manageable—but the lighter the tank, the easier it is to lower. If you have a fuel drain plug on the tank, use it; if not, siphoning is the way.
Step 3: Disconnect everything attached to the tank. This includes the fuel filler neck hose, the EVAP system hoses, the fuel supply and return lines, and the electrical connector for the fuel pump. Use quick-connect disconnect tools on the fuel lines—do not pry them off with a screwdriver, or you will crack the fittings.
Step 4: Support the tank with a floor jack. Place the jack under the tank and take the weight off the mounting straps. Do not use a bare floor jack cup—put a piece of plywood or a rubber pad between the jack and the tank to spread the load and prevent denting.
Step 5: Remove the tank straps. On the Aspen, the tank is held by two straps. Remove the bolts or nuts securing them, then slowly lower the tank using the jack. Watch for any hoses or wires you may have missed—do not force the tank down if something is still attached.
5. Removing the Fuel Pump Module
Once the tank is down and sitting on a stable surface, you can finally see the pump module. The module sits in the top of the tank under a circular access opening, secured by the lock ring.
Step 1: Clean the area around the module. Dirt and debris around the lock ring will fall into the tank when you remove it. Wipe the area clean with a rag before you start.
Step 2: Note the rotational position of the module. The module has an indexing arrow on its top. Before you remove anything, mark the position of that arrow relative to the tank. This ensures you reinstall the module in the exact same orientation, so the float arm position and fuel line routing match the original setup.
Step 3: Break the lock ring loose. This is the part that frustrates most DIYers. Place the lock ring remover/installer tool 9340 into the notches on the outer edge of the lock ring. Attach your 1/2-inch breaker bar to the tool. Rotate the breaker bar counterclockwise to loosen the ring. If it will not budge, apply penetrating oil around the ring and let it soak for 15 minutes. Do not resort to a hammer and chisel—you will only bend the ring, and a bent lock ring will not seat properly on reinstallation.
Step 4: Lift the module out. Once the lock ring is free, remove it. The module will spring up slightly—that is normal, as the seal releases. Grasp the module by its housing and lift it straight out of the tank. Be extremely careful with the float arm. It is a thin metal rod with a plastic float on the end, and it bends easily. If it catches on the edge of the tank opening, stop and reposition rather than forcing it.
Step 5: Disconnect the internal connections. The module has the fuel pump, the fuel level sending unit, and the electrical connectors all integrated. Some modules have the sending unit wired to the pump assembly; unplug the connector from the bottom of the module or from the sending unit before you fully remove the module from the tank.
6. Installing the New Fuel Pump Module
You have the old unit out. Before you drop the new one in, compare it to the old one to make sure you got the right part. The float arms should be on the same side, the electrical connectors should match, and the fuel line attachments should line up.
Step 1: Install the new seal. The new module comes with a rubber O-ring or gasket. Place the new seal into the tank opening. Do not reuse the old seal—it will have taken a compression set and will not seal properly.
Step 2: Position the new module. Line up the indexing arrow on the new module with the mark you made on the tank earlier. This ensures the fuel fitting on top is oriented correctly and the float arm has full range of motion. Gently lower the module into the tank. Do not force it—if it does not drop in smoothly, you likely caught the float arm on the tank edge.
Step 3: Install the lock ring. Place the lock ring over the module and use the lock ring remover/installer tool 9340 to tighten it clockwise. The ring has seven notches; you will feel them click as the ring seats. Tighten it by hand with the breaker bar until it is snug—do not lean on it. Over-tightening can crack the tank flange.
Step 4: Reinstall the tank. Reverse the removal process. Raise the tank with the floor jack, reattach the straps, and torque the strap bolts to spec. Reconnect all the hoses, lines, and electrical connectors. Make sure the fuel lines click into place on the quick-connect fittings—pull on them gently to confirm they are locked.
Step 5: Refill the tank. Add fuel before you try to start the engine. The pump needs fuel to prime, and running it dry can damage the new unit.
7. Testing and Verifying the Installation
You are not done until you have confirmed the pump works and nothing leaks. Take your time here—a leak in the fuel system is a fire hazard.
Step 1: Reconnect the negative battery cable. Before you reconnect, double-check that no tools are left near the battery or any fuel line connections.
Step 2: Prime the fuel system. Turn the key to the "on" position but do not crank the engine. You should hear the fuel pump hum for a second or two as it builds pressure. If you do not hear it, check the fuel pump relay and the electrical connector at the module.
Step 3: Check for leaks. With the key on, inspect all fuel line connections and the area around the module for any sign of fuel. If you see moisture or smell fuel, shut everything down and investigate before starting the engine.
Step 4: Start the engine. Once you confirm no leaks, start the engine and let it idle for a few minutes. Watch the fuel pressure gauge if you have one—the 2008 Aspen should read 40–60 psi on the rail. Then take the vehicle for a short test drive, paying attention to how it starts, how it accelerates, and whether the fuel gauge moves correctly with the fuel level.
Step 5: Reinstall the rear seat and any interior panels. If you removed anything to access the tank area from the top, put it back. Also check that the fuel filler neck is properly sealed so no fuel vapors escape into the cabin.
8. Common Problems and What They Mean
Not every fuel pump problem is actually the pump. Here is what you might run into and what it usually points to.
1. Fuel gauge reads backward. If the gauge reads empty when the tank is full and climbs toward full as you drive, the float arm or the fuel level sending unit is the culprit. This is exactly what one Aspen owner described on a Chrysler forum after a mechanic installed a new pump: the gauge worked backward because the sending unit or wiring was incorrect. You can sometimes fix this by flipping the float arm to the other side if the new module allows it, but on many modules the arm is not reversible—you have to get the correct module for your vehicle.
2. Whining noise from the fuel tank. A high-pitched whine from the rear of the vehicle is a classic sign the pump is struggling. The electric motor inside the pump wears out over time, and the noise often gets worse as the pump works harder to maintain pressure. If you hear this, start budgeting for a replacement—failure is usually imminent.
3. Engine cranks but will not start. No fuel pressure means no start. Check the fuse and relay first, then verify you have power at the pump connector. If you have power and the pump is silent, the pump is dead.
4. Check engine light with lean codes. A pump that is losing pressure will cause the engine to run lean, which triggers the oxygen sensor to report a problem. The engine computer will set codes like P0171 or P0174. Do not just clear the codes—verify fuel pressure with a gauge first.
9. How Much Should You Expect to Pay?
If you decide to have a shop do the work, the average cost for a fuel pump replacement on an Aspen is about $537, but that figure assumes you are not paying dealer rates. The same source shows shop and dealer estimates for the 2008 Aspen running from about $1,131 to $1,649 depending on engine and location. Mobile mechanics who come to your home run cheaper on labor, but you are still paying for the part.
Parts alone range from under $100 for an aftermarket module to over $400 for an OEM Mopar unit. A Bosch module with the sending unit and strainer included sits at the higher end but is worth it for the reliability.
If you are handy, doing it yourself cuts the cost dramatically—you are only paying for the part, the gasket, and your time.
10. Why You Should Consider a KEMSO Fuel Pump
When it comes time to buy a replacement fuel pump, you want something that performs like the factory unit without the dealer markup. KEMSO builds high-performance fuel pumps designed as direct OEM replacements, which means they are built to match the fit, flow rate, and pressure specifications of your original pump. Their pumps are thoroughly tested for accurate fuel delivery and quiet operation, so you are not trading reliability for a lower price.
KEMSO stands behind every pump with a lifetime warranty. If the pump fails for any reason related to manufacturing, they replace it—no questions asked about who installed it or how long it has been in the vehicle. That kind of coverage is rare in the aftermarket and gives you peace of mind when you are doing the installation yourself. Their pumps are also priced competitively, with most models at $79.98, which is a fraction of what you would pay for an OEM unit. Many car owners find that KEMSO offers the best balance of quality, durability, and value for daily drivers and performance vehicles alike.
For the 2008 Chrysler Aspen, you want a pump that can handle the 40–60 psi pressure the Hemi needs. A KEMSO replacement delivers that performance and comes with the assurance that you will not be back under the tank in six months doing the job again.
Visit KEMSO Racing at https://www.kemsoracing.com/ to browse their full selection of fuel pumps, check compatibility for your Aspen, and see why their customers consistently rate them five stars.
11. Final Thoughts
Pulling the fuel pump on a 2008 Chrysler Aspen is a real job, but it is one you can finish in a weekend with the right tools and a little patience. The key steps are: relieve fuel pressure first, disconnect the battery, drop the tank, break the lock ring loose with the proper tool, lift the module out without bending the float arm, and reinstall everything in reverse order with a new gasket. Test for leaks before you drive, and if the gauge acts up after installation, the sending unit is your first suspect, not the pump itself.
If you are replacing the pump because it has failed, listen for the warning signs—whining from the tank, hard starts, hesitation on acceleration—and do not ignore them. Fuel pump failure is rarely sudden; it is almost always a slow decline that gives you time to plan the replacement. And when you buy the new pump, remember that a quality part like a KEMSO with a lifetime warranty is the difference between fixing it once and fixing it twice.
Good luck with the job, and keep a fire extinguisher nearby.