What an Oil Pump Core Charge Is for Detroit Diesel Engines and Why Diesel Pro Power Charges One

When purchasing a rebuilt or remanufactured oil pump for a Detroit Diesel engine, customers will often see an additional refundable fee known as a core charge. Many operators are familiar with core charges for blowers, injectors, water pumps, or cylinder heads, but may not realize that oil pumps also require cores to maintain the supply of rebuildable units. Understanding what this fee represents—and why Diesel Pro Power must charge it—helps customers make informed purchasing decisions and avoid surprises at checkout.

This article explains what an oil pump core charge is, why it exists, and how returning your used oil pump benefits both you and the broader Detroit Diesel owner community.

To get refunded for your oil pumps core charge fill out a Return Of Goods Authorization Form before returning your used oil pump. 

What Is an Oil Pump Core Charge?

A core charge is a temporary deposit added to the purchase price of a rebuilt Detroit Diesel oil pump. The “core” refers to the used oil pump that comes off your engine when you replace it. Once you return your old oil pump to Diesel Pro Power and it is inspected and confirmed to be rebuildable, the core charge is refunded to you in full.

In other words:

• You buy a rebuilt oil pump and pay the core deposit.

• You install the new pump.

• You send the old pump back.

• Diesel Pro Power inspects it.

• If it is rebuildable, the deposit is returned.

This system ensures a continuous supply of oil pump housings and internal components that can be restored, rebuilt, and resold to future customers.

Why Oil Pumps Require a Core Charge

Detroit Diesel oil pumps—especially those for legacy two-stroke engines like the 6-71, 8V71, 12V71, 8V92, and 16V92—are no longer produced in large quantities as new units. In many cases, Detroit Diesel stopped manufacturing certain components years ago. The only way to keep rebuilt oil pumps available for global operators is to recover and rebuild existing units.

Several key reasons make the oil pump core charge necessary:

1. Oil Pumps Contain Hard-to-Find OEM Castings

The pump housing, internal cavity, and gear chamber are specific to each Detroit Diesel engine model. These castings are precision-machined and designed to exact tolerances. Because Detroit Diesel no longer mass-produces these castings, good housings must be recycled through the rebuild process.

Without core returns, there is no reliable source of rebuildable housings.

2. Rebuilt Oil Pumps Depend on Your Used Pump

A rebuilt oil pump is not simply cleaned and reassembled. It goes through a full remanufacturing process that includes:

• Disassembly

• Industrial cleaning

• Machining of critical surfaces

• Replacement of internal gears and bearings

• Installation of new pressure relief valves or springs (as required)

• Clearance inspection

• Flow and pressure testing

This process requires the original pump as a foundation. Without a returned core, Diesel Pro Power cannot produce more rebuilt pumps.

The core charge ensures that pump housings and internal gear bodies continue circulating back into the inventory.

3. Many Oil Pumps Are Damaged or Worn Beyond Use

Not every oil pump that comes off an engine is rebuildable.

Cores that cannot be used include those with:

• Cracked housings

• Deep scoring from loss of lubrication

• Excessive gear cavity wear

• Broken gears

• Rust or corrosion damage

• Failed pressure relief components

• Severe metal contamination

Because Diesel Pro Power must screen every returned pump, the core charge helps offset the cost of receiving, handling, and evaluating cores—especially those that turn out to be unusable.

4. Ensures Inventory Stability for Global Customers

Operators around the world—from commercial fishing vessels to industrial generators—depend on Detroit Diesel parts. Diesel Pro Power ships to more than 180 countries, and fast availability is essential in preventing customer downtime.

Oil pump core returns help:

• Maintain steady inventory

• Reduce lead times

• Keep rebuilt pumps available with no waiting

• Prevent shortages during peak seasons

Without core charges, too many customers would discard or scrap their old oil pumps, disrupting the supply chain.

5. Keeps Rebuilt Oil Pump Prices Affordable

Rebuilt oil pumps are significantly less expensive than new-manufactured versions—if new ones can even be found. The core program allows Diesel Pro Power to keep pricing far below the cost of manufacturing new units from scratch.

Returned cores allow the company to:

• Reuse the most expensive structural components

• Reduce material costs

• Limit dependency on rare OEM stock

• Maintain pricing stability even when demand rises

Core charges directly help rebuilders keep high prices in check for customers.

Why Diesel Pro Power Charges an Oil Pump Core Charge Specifically

Diesel Pro Power is one of the largest suppliers of Detroit Diesel parts in the world, and maintaining a consistent supply of rebuilt components requires constant recycling of cores. Detroit Diesel two-stroke engines remain in service globally, but parts availability depends entirely on the return flow of rebuildable components.

Diesel Pro Power charges an oil pump core charge because:

1. It ensures enough rebuildable pumps are collected to support worldwide demand.

2. It allows the company to maintain high-quality rebuilt inventory that ships immediately.

3. It prevents the loss of essential castings that cannot be reproduced easily.

4. It supports the expert rebuild process, which requires substantial labor and testing.

Without core returns, Diesel Pro Power would not be able to supply reliable rebuilt oil pumps at competitive prices.

The Customer Benefits of Returning Your Oil Pump Core

Although some customers are initially frustrated by core charges, returning your oil pump core is ultimately beneficial.

You receive your refund back in full

As long as the core is rebuildable, the entire charge is returned.

You help preserve Detroit Diesel engines

Returned cores help keep these classic engines operating for decades to come.

You ensure parts remain available

The same system that benefits you today will benefit future operators who rely on rebuilt components.

You support environmentally responsible rebuilding

Reusing housings and castings reduces metal waste and industrial energy consumption.

Final Thoughts

A core charge is not a penalty; it is an essential part of the remanufacturing system that keeps Detroit Diesel engines running worldwide. Oil pumps are critical to engine lubrication, and rebuilt pumps depend entirely on the return of usable cores. Diesel Pro Power maintains one of the strongest inventories of Detroit Diesel rebuilt parts in the industry, and core charges help ensure the continuing availability of these components.

By returning your used oil pump, you receive your deposit back, support the availability of rebuilt pumps, and help keep Detroit Diesel legacy engines operating reliably across the globe.

To get refunded for your oil pumps core charge fill out a Return Of Goods Authorization Form before returning your used oil pump. 

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