Bobcat Injector Removal Guide for D18, D24 & D34 Engines

We have talked a lot about diesel fuel injectors in some of our other blogs, but today we are going to go over how to remove a diesel fuel injector from a Doosan Bobcat engine. 

Removing a fuel injector from a Bobcat machine powered by a Doosan engine is one of the most critical service skills for owners, mechanics, and fleet technicians. The process is not technically complicated, but it demands precision, cleanliness, and the right tools. Done correctly, injector removal helps you complete diagnostics, replace faulty nozzles, maintain fuel pressure, or perform preventive fuel system service. Done incorrectly, it can cause fuel-line damage, contamination, costly part failures, and unnecessary downtime.

Many operators skip recommended safety and cleaning steps. Skipping prep commonly leads to debris lodging in fuel rails, damaged hold-down bolts, improper sealing, and microscopic particles entering the combustion chamber or high-pressure pump system. One overlooked detail can create injector spray failure, low common rail pressure, and shortened system life. This 3-engine guide explains exactly how to perform injector removal safely while keeping your fuel lines intact and your system contaminant-free.

Common Reasons to Remove a Fuel Injector

There may be several reasons why you might need to remove an injector. Perhaps you are looking at doing some maintenance work on your parts in which case, you should also review this guide on how to clean your injector(s) at home. Or you may be experiencing some issues with your machine and need to test your injectors to determine if they are faulty. 

Bobcat Machines: Where These Injectors Live

Bobcat equipment, especially compact units like skid steers and excavators, often use injectors built into the fuel rail assembly. The newer Bobcat machines (2015+) are likely using the Doosan engines which include D18, D24, D34, DM01, DM02 and DM03 models. While torque specs vary slightly between models, the injector hold-down architecture and access points look nearly identical across these engine fuel systems.

If you do have any questions about anything related to removing an injector or about our parts, you can also contact us at contact@expertdieselparts.com. 

Safety & Prep Before Starting

High pressure fuel injection systems can still leak fuel long after shutdown. A fuel rail holds intense pressure, and hot engine components increase safety risk. Before removal, always complete these steps:

1. Let the engine cool down for at least 60 minutes before service.
2. Wear protective gloves and safety eyewear to avoid fuel contact.
3. Work in a debris-free environment if possible.
4. Remove only the fuel line attached to the injector you are reversing unless you plan to remove all injectors. This prevents damaging or weakening fuel line threading, caps, and seals. 

Key Risk Note: Poor fuel line handling is the most common point of error. These lines are tightly bolted at both ends and are difficult to reseal once removed. Never loosen fuel lines without a clear removal reason.

What You’ll Need: 

• Lint-free cloth or towel
• Fuel-resistant gloves
• Impact-rated safety eyewear
• 8mm socket wrench
• 6mm hex Allen set
• Plastic cap tray or magnetic bin (optional but helpful for bolt storage)
• O-ring lubricating gel or clean engine oil 
• Replacement injector rail o-ring for reinstall or rebuild

Steps: 

#1 Remove the Airbox and Rubber Fuel Caps

The airbox restricts direct access to the injectors. Start by removing the airbox to get access to the injectors. Unbolt and gently lift it off. Each injector head includes a rubber dust cap. Pull off every dust cap carefully, exposing the metal fuel line covers above the top engine housing.

#2 Wipe Down Dirt 

Before you start removing any other parts, grab a lint-free cloth or a towel and clean off any dirt, dust and particles that could potentially fall into your engine. 

#3 Remove the PCV Tubing to Reveal Injector Hold-Down Cap Bolts 

Next, you will need to get access to the injector hold down bolt. Pull back the PCV tube to view the hold-down clamp bolt. This is where you will later insert your 6mm hex Allen driver. Do not detach unrelated fuel lines. (Unlike other fuel systems, experienced mechanics recommend not removing every fuel line to prevent potential contamination or damage to all of the fuel lines.) Only remove PCV and the necessary injector fuel-line cover.

These fuel lines are bolted down pretty firmly and it can be easy to damage a fuel line or not properly seal it back. The goal here is to remove ONLY the fuel line that is attached to the injector that you absolutely need to remove. 

#4 Remove Fuel Rail Top Cover (10-12 bolts on avg)

Next, you will need to pull off the top cover that sits underneath the fuel lines. Make sure to remove the cover before removing the injection fuel lines. Start by grabbing an 8 millimeter socket wrench and remove each screw placed around the cover. There are about 10 screws that go around the cover. Each will need to be removed. Once all screws are off, remove the cover. 

#5 Unscrew and Remove the Fuel Line

Once the cover is removed you now have access to the injectors hold down assembly. Now go ahead and remove the fuel line on the injector that you need to replace by unscrewing both caps on each end of the fuel line. 

#6 Remove Hold Down Clamp

Next, grab a 6 millimeter hex allen head (make sure the bottom of the allen head is not rounded off since the bolts are incredibly tight). Refer back to the injector hold down clamp. You will need to remove the hold down clamp and the bolt. Carefully ensure that the hex allen head is fully seated in the nut of the bolt. First, you will need to loosen the bolt. Once loosened, remove the bolt and place it to the side. Next, remove the hold down. You might have to further loosen it up by moving the injector to remove the hold down bolt. 

#7 Remove Safety Lock and Unplug Injector

Now that the hold down clamp is removed you can detach the injectors safety lock and unplug the injector. You may have to loosen the injector with help from a wrench. 

#8 Check for O-Ring

Once your injector is removed, be sure to check that the o-ring attached to the injector also came out. When removing injectors, the o-rings can sometimes get stuck in the rail. Regardless of whether you are cleaning or replacing the injector, we recommended using a new o-ring seal, just make sure you put lubricant when placing a new o-ring. 

And that’s it! Whether you need to clean the injector, take it to a dealer, or replace it, it’s a fairly simple process to remove a fuel injector from a Doosan Bobcat engine. Please remember that unless you need to take out all 4 of the injectors, we recommend only removing the ones necessary to prevent damaging fuel lines. 

We sell a wide range of parts including the entire fuel system kits for the D24, D34 and D18 engines. Purchase your parts from us today or reach out if you have any questions. 

The information provided in this article is for general guidance only. Always refer to your machine’s manual or consult a qualified mechanic before performing any maintenance or repairs.