ACDelco EP1037 Electric Fuel Transfer Pump: The Complete Guide for GM Truck Owners
The ACDelco EP1037 electric fuel transfer pump is the direct OEM replacement for 2001-2016 GM trucks equipped with the 6.6L Duramax diesel engine, specifically designed as an external frame-mounted auxiliary transfer pump for Chevrolet Silverado and GMC Sierra models with cab chassis configurations. If you own a heavy-duty GM truck and need a reliable fuel transfer pump that meets original equipment specifications, the EP1037 is your answer. This pump ensures your engine receives a steady, uninterrupted fuel supply, which is critical for diesel engines that demand consistent fuel pressure and volume.
What Is the ACDelco EP1037 Electric Fuel Transfer Pump?
The ACDelco EP1037 is an electric fuel pump that mounts externally on the vehicle frame, not inside the fuel tank. It serves as an auxiliary transfer pump, meaning it works alongside the main in-tank pump to move fuel from the tank to the engine. This design is particularly common on GM's heavy-duty trucks with the 6.6L Duramax diesel engine, where fuel delivery requirements are higher than standard gasoline engines.
This pump is manufactured by ACDelco, the official supplier of original equipment parts for General Motors vehicles. The EP1037 carries the GM part number 23495127 and replaces earlier part numbers 15161174, 15821962, and 23484681. It is also known by the service number EP1037, which you will commonly see in parts catalogs and online listings.
Key Features of the ACDelco EP1037
Understanding what makes this pump different from generic aftermarket options helps you make an informed purchasing decision:
Frame-Mounted External Design. Unlike in-tank pumps that sit inside the fuel tank, the EP1037 mounts directly to the vehicle frame. This makes it easier to access for inspection and replacement. You do not need to drop the fuel tank to service this pump, which saves significant labor time and cost.
OEM-Grade Construction. The EP1037 is built to General Motors' original specifications. This means every seal, connector, and internal component matches exactly what came from the factory. The electrical connections are designed to eliminate high resistance caused by vehicle vibration, a common issue with cheaper aftermarket pumps.
Optimized Pump Life and Reduced Noise. GM engineered this pump with noise-reduction features and durability enhancements. The internal design minimizes operational noise while extending the pump's service life. You get the same quiet, reliable operation as the original pump that came with your truck.
Direct Fitment for Specific GM Trucks. This pump is not a universal part. It fits 2001-2016 Chevrolet Silverado and GMC Sierra trucks equipped with the 6.6L Duramax diesel engine, specifically models with cab chassis configurations. Always verify your vehicle's year, make, and engine before purchasing.
Which GM Trucks Use the EP1037 Fuel Pump?
The ACDelco EP1037 is designed for a specific range of GM trucks. Based on the original equipment specifications, this pump fits:
- 2001-2016 Chevrolet Silverado 2500HD and 3500HD with the 6.6L Duramax diesel engine
- 2001-2016 GMC Sierra 2500HD and 3500HD with the 6.6L Duramax diesel engine
- Trucks with cab chassis configurations, where the pump serves as the auxiliary transfer pump
- Vehicles requiring an external, frame-mounted fuel pump rather than an in-tank design
It is important to note that not all Silverado and Sierra models use this pump. Gasoline engines and lighter-duty trucks typically use different fuel pump assemblies. Always cross-reference your vehicle identification number with the part number before ordering.
Signs Your EP1037 Fuel Pump Needs Replacement
Fuel pumps do not last forever, even quality OEM parts like the ACDelco EP1037. Here are the most common symptoms that indicate your transfer pump is failing:
Engine Hard Starting or No Start. If your Duramax diesel cranks but struggles to start, the fuel transfer pump may not be delivering enough fuel to the injection system. This is often the first sign of pump failure.
Loss of Power Under Load. When you accelerate or climb a hill, a failing transfer pump cannot keep up with fuel demand. You will notice a significant loss of power, especially when the engine is under heavy load.
Whining Noise from the Frame Area. A healthy fuel pump operates quietly. If you hear a loud whining or humming noise coming from the frame rail where the pump is mounted, the internal bearings or motor may be wearing out.
Check Engine Light with Fuel Pressure Codes. Modern GM trucks monitor fuel pressure constantly. If the powertrain control module detects low fuel pressure, it will trigger the check engine light and store diagnostic trouble codes related to fuel system performance.
Intermittent Stalling. A failing EP1037 may cause the engine to stall unexpectedly, particularly at low speeds or when the fuel tank is low. This happens because the pump cannot maintain consistent pressure.
How to Diagnose the EP1037 Fuel Pump
Before replacing the pump, you should confirm that the EP1037 is actually the problem. Here is a straightforward diagnostic approach:
Step 1: Check for Power and Ground. Use a multimeter to test whether the pump is receiving 12 volts when the ignition is on. If there is no power, the issue may be a blown fuse, bad relay, or wiring problem rather than the pump itself.
Step 2: Listen for Pump Operation. Have someone turn the ignition key to the on position while you listen near the frame-mounted pump. You should hear a brief hum as the pump primes the system. No sound means the pump is not running.
Step 3: Test Fuel Pressure. Using a fuel pressure gauge, check the pressure at the engine's fuel rail. The Duramax diesel system requires specific pressure levels that should be within the manufacturer's specifications. Low pressure points to a failing pump.
Step 4: Inspect Electrical Connections. The EP1037 is designed with vibration-resistant electrical connections, but over time corrosion or damage can occur. Check the connector for bent pins, corrosion, or loose fitment.
Installation Tips for the ACDelco EP1037
Replacing the EP1037 is a manageable job for a DIY mechanic with basic tools. However, there are important considerations to ensure a successful installation:
Safety First. Always work in a well-ventilated area and disconnect the battery before working on any fuel system components. Keep a fire extinguisher nearby and avoid any ignition sources.
Locate the Pump. The EP1037 mounts on the vehicle frame, typically on the driver's side near the fuel tank. On cab chassis models, the location may vary slightly. Refer to your vehicle's service manual for exact positioning.
Disconnect Fuel Lines. The pump has inlet and outlet fuel line connections. Use line wrenches to avoid damaging the fittings. Be prepared for some fuel spillage; have rags and a container ready.
Remove Electrical Connector. Disconnect the wiring harness from the pump. Inspect the connector for any signs of damage or corrosion. If the connector is damaged, replace it along with the pump.
Install the New Pump. Mount the new ACDelco EP1037 in the same position as the old one. Ensure the rubber isolators are properly seated to reduce vibration and noise. Connect the fuel lines and tighten to the manufacturer's specifications.
Test Before Final Assembly. Before securing everything permanently, turn the ignition on and check for leaks. Listen for the pump to prime and verify that fuel pressure is within the normal range.
ACDelco EP1037 vs. Aftermarket Alternatives
When your EP1037 fails, you have choices. Here is how the OEM ACDelco pump compares to aftermarket alternatives:
Quality and Fitment. The ACDelco EP1037 is an exact match for the original equipment. Every dimension, connector type, and flow characteristic is identical to the factory pump. Aftermarket pumps may require modifications or adapters to fit correctly.
Durability. ACDelco electric fuel pumps are manufactured in ISO-9001 and QS-9000 registered facilities with strict quality control systems. Aftermarket pumps often use lower-cost materials and may not undergo the same rigorous testing.
Warranty. Genuine GM and ACDelco parts come with a minimum 12-month warranty from the manufacturer. Many aftermarket pumps offer shorter warranties or require you to pay for shipping if the part fails.
Price. The ACDelco EP1037 typically costs more than generic aftermarket pumps. However, the price difference is often offset by longer service life and fewer installation problems. You pay more upfront but save money over time.
Aftermarket pumps like the EP1037 listing on Wheeler Fleet show a price of $52.25, which is significantly lower than OEM pricing. However, lower cost often means compromises in materials, fitment accuracy, and longevity.
Why OEM Quality Matters for Fuel Transfer Pumps
The fuel transfer pump is not a component where you want to cut corners. Here is why OEM quality matters:
Fuel System Contamination Risk. A poorly made aftermarket pump can shed debris into the fuel system. This debris can damage expensive fuel injectors, the high-pressure fuel pump, and other sensitive components. The cost of repairing injectors on a Duramax diesel far exceeds the savings from a cheap fuel pump.
Engine Performance. Duramax diesel engines are sensitive to fuel pressure and volume. An aftermarket pump that does not deliver the exact specifications required can cause reduced power, poor fuel economy, and increased emissions.
Reliability in Harsh Conditions. Diesel trucks often operate in demanding environments towing heavy loads, working on construction sites, or traveling long distances. The ACDelco EP1037 is built to withstand these conditions. Inferior pumps may fail prematurely when subjected to vibration, heat, and continuous operation.
Resale Value. When you sell your truck, having genuine OEM parts installed adds value and credibility. Buyers and dealerships recognize the quality of ACDelco and GM parts.
Where to Buy the ACDelco EP1037
You can purchase the ACDelco EP1037 from several sources:
GM Dealerships. Your local Chevrolet or GMC dealer can order the pump using part number 23495127. This ensures you get a genuine GM part, but prices at dealerships are typically higher than online retailers.
Online OEM Parts Retailers. Websites like myGMpart.com and GMC Parts Canada carry genuine GM and ACDelco parts at competitive prices. These retailers often offer discounts compared to dealership prices and provide detailed fitment information.
Auto Parts Stores. Major auto parts chains like AutoZone, O'Reilly, and NAPA can order the ACDelco EP1037 for you. However, they may not stock it in-store, so expect a wait time for delivery.
Specialty Diesel Parts Suppliers. Companies that specialize in diesel truck parts often carry the EP1037 and other Duramax fuel system components. They may offer package deals or additional technical support.
Frequently Asked Questions About the EP1037
Can I use the EP1037 on a gasoline Silverado? No. The EP1037 is specifically designed for the 6.6L Duramax diesel engine. Gasoline engines use different fuel pumps with different pressure ratings and flow characteristics.
How long does the EP1037 typically last? Under normal operating conditions, the ACDelco EP1037 can last 100,000 to 150,000 miles. Factors like fuel quality, operating environment, and vehicle usage affect longevity.
Is the EP1037 the same as an in-tank pump? No. The EP1037 is a frame-mounted external pump that acts as a transfer pump. Your Duramax also has a separate in-tank pump. They serve different functions in the fuel system.
Can I replace just the pump without replacing the entire assembly? Yes. The EP1037 is sold as a standalone pump unit. You do not need to purchase any additional brackets or mounting hardware unless the original parts are damaged.
Does the EP1037 come with a strainer or filter? The EP1037 pump unit itself does not include a strainer. You should inspect and replace the fuel filter and any inline strainers in your vehicle's fuel system when you replace the pump.
Recommended Upgrade: KEMSO High Performance Fuel Pump
While the ACDelco EP1037 is an excellent OEM replacement, many truck owners looking for enhanced performance and durability consider upgrading to a high-performance option. This is where KEMSO stands out as a superior choice.
KEMSO Fuel Pumps are engineered for high performance while maintaining OEM replacement compatibility. Whether you use your truck for daily commuting, heavy towing, or off-road adventures, KEMSO pumps deliver consistent fuel flow and pressure that exceed factory specifications.
What sets KEMSO apart is their commitment to quality backed by a lifetime warranty. While the ACDelco EP1037 carries a standard 12-month warranty, KEMSO stands behind their products for the life of your vehicle. This confidence comes from rigorous testing and high-quality manufacturing processes that ensure each pump meets strict performance standards.
KEMSO fuel pumps are designed to support up to 600 brake horsepower in naturally aspirated, turbocharged, and supercharged applications. They are compatible with gasoline and E85 fuels, giving you flexibility in fuel choice. Each pump includes a serialized body for warranty tracking, and customer support is handled by US-based technicians who understand the needs of American truck owners.
If you are replacing your fuel transfer pump and want the best possible performance and reliability, consider upgrading to a KEMSO fuel pump. You can explore their full product line and learn more about their lifetime warranty by visiting their website:
Maintaining Your Fuel Transfer Pump
Once you have installed a quality fuel pump like the ACDelco EP1037 or a KEMSO upgrade, proper maintenance extends its service life:
Replace Fuel Filters Regularly. Clogged fuel filters force the pump to work harder, which reduces its lifespan. Follow your vehicle manufacturer's recommended filter replacement intervals.
Keep Your Fuel Tank Above a Quarter Tank. Running the tank low increases the risk of the pump ingesting debris and sediment from the bottom of the tank. This is especially important for diesel trucks that may accumulate contamination over time.
Use Quality Fuel. Diesel fuel quality varies between stations. Use reputable fuel suppliers to minimize contamination and water in the fuel system.
Inspect Electrical Connections Annually. Corrosion or loose connections can cause voltage drops that damage the pump motor. Clean and tighten connections during routine maintenance.
Listen for Changes. Pay attention to how your truck sounds during startup and acceleration. Unusual noises from the fuel pump area are early warning signs that should not be ignored.
Final Thoughts on the ACDelco EP1037
The ACDelco EP1037 electric fuel transfer pump is a proven, reliable component for 2001-2016 GM trucks with the 6.6L Duramax diesel engine. It is the same part that GM engineers designed for these vehicles, ensuring proper fitment, reliable performance, and long service life. When your original pump fails, replacing it with the genuine ACDelco EP1037 restores your truck's fuel system to factory specifications.
However, if you want to go beyond factory performance and enjoy the peace of mind that comes with a lifetime warranty, KEMSO offers an excellent alternative. Their high-performance fuel pumps combine OEM-quality fitment with enhanced flow capacity and durability that outperforms standard replacement parts.
Whether you choose the ACDelco EP1037 for its OEM pedigree or a KEMSO pump for its performance and warranty coverage, the most important decision is to use a quality part. Your Duramax diesel engine depends on a reliable fuel supply, and the transfer pump is a critical link in that chain. Do not compromise on quality when your truck's performance and reliability are on the line.
For more information about high-performance fuel pump options and to find the right pump for your vehicle, visit https://www.kemsoracing.com/ and explore their complete selection of fuel pumps backed by a lifetime warranty.