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A Guide to Identifying Weld Bungs

A Guide to Identifying Weld Bungs

Weld bungs are sometimes damaged or can break when repairing aftertreatment systems – often due to galling, corrosion, or the threads being stripped out. Dealing with a busted bung is frustrating enough for your customers, getting the wrong bung makes that frustration even worse. Be the hero to your customers by removing the guesswork and thus making diesel emissions easier for them.

Broken bungs will likely always be a thing we have to deal with, so having the tools and knowledge to ensure the correct bung is ordered is important. In this Guide to Identifying Weld Bungs, we’ll go through some ways to help parts people and your customers identify the correct weld bung for their repair.

PRO TIP #1: Start small, save big…

PRO TIP #1: Start small, save big…

Instead of purchasing a whole new DPF ($1,000 and up) because the bung broke off, replace the weld bung for a fraction of the cost.

The Easy Way

If you’re pressed for time, see if you can determine the OEM part number of the sensor, DPF, or DOC that connects to the bung port in need of replacement and where the port is located on the part – as there are often multiple sensor ports.

Then contact REP Support at 1-888-564-4209. In most cases, we can determine the correct bung you or your customer needs with this information.

PRO-TIP #2: An ounce of prevention…

PRO-TIP #2: An ounce of prevention…

Our REP Sensors ship with anti-seize included that is designed to help prevent dreaded bung breakage. Apply anti-seize during sensor installation for added protection from galling.

The “Scientific Method” – Nerd Out

Start by studying our Weld Bung Guide infographic to learn about Flare Type – Normal, Reversed, or Flat, and Style – which is basically the Bung shape. These are the most common styles/shapes: Standard, Stepped, or Plug/male thread. There are other shapes, but they are not seen as much.

Also, check out the REP Weld Bungs page and see the Weld Bung Brochure PDF to get informed on the vast selection of bungs REP has available.

Note the Location/Function

Consider the sensor types and their locations within the exhaust system, these include oxygen (O2), nitrogen oxides (NOx), temperature, and pressure sensors.


Measure the existing bung, and also determine the thread size and pitch, flare type, and style. Use a thread gauge rather than eyeballing it. The common thread sizes range from M10 to M22, with pitches of 1.0, 1.25, and 1.5. Noting flare and style are also important to make sure that the weld bung and sensor are compatible. To review:

  • Flare Type: Normal, Reversed, or Flat
  • Style: Bung shape: Standard, Stepped, or Plug (Male Thread)

You can also measure dimensions like Outer Diameter (OD), Inner Diameter (ID), and Height. Armed with this data, you can confidently choose the correct bung.

PRO-TIP #3: Quality Counts…

When it comes to bungs it’s important to recommend to your customers a high-quality stainless-steel bung that can withstand the harsh exhaust environment, such as bungs from a reputable brand like Redline Emissions Products.

Get Expert Advice

If you’re unsure about which bung to recommend, again you can contact REP Support at 1-888-564-4209 Or even ask a qualified diesel mechanic—either one should be to help you find the right bung for your customer. You can also get in touch with a reputable, local auto parts retailer or online store specializing in diesel emissions systems as they offer valuable resources and assistance in selecting the right weld bung.

Redline Emissions Products® is your source for aftermarket OEM replacement weld bungs. High-quality. Huge inventory. Period.

Redline Emissions Products is the industry leader in simplifying the diesel emission system. With our expertise and dedication to excellence, we ensure a seamless experience for our customers. Browse our website to learn more about our extensive range of aftertreatment products, equipment, and services.

Redline Emissions Products Logo

Any questions? Our Diesel Emissions parts & DPF Cleaning experts are here to help.

For inquiries or more information on our aftertreatment parts, DFP Cleaning equipment, or how to become an authorized REP distributor, feel free to contact us. We are here to assist you and provide the support you need every step of the way.

Contact Wayne Cochrane, National Sales Manager for REP to find out more.  Call 888-295-4670

Need Tech Support or need help troubleshooting a DPF problem? No problem! Contact REP Support at 1-888-564-4209

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