Skip to main content
DPF Clamps: How to Prevent Exhaust Leaks

DPF Clamps: How to Prevent Exhaust Leaks

In the world of diesel engines and emissions control, even seemingly simple components like DPF clamps play a crucial role in ensuring optimal performance and avoiding issues with the diesel emissions system. In this article, we’ll dive into the proper installation of DPF clamps (sometimes called V-Band Clamps), a topic that often gets overlooked. This is important because when done incorrectly, it can often lead to exhaust leaks, creating many different issues with the emissions system.

Here are the three things you need to know about (Diesel Particulate Filter) DPF clamps to prevent exhaust leaks:

DPF Clamps: How to Prevent Exhaust Leaks

#1 – Understanding the Engineering Behind DPF V-Band Clamps

There is a lot of engineering that goes into a very simple DPF clamp. The angles on the flange must match the apex of the v-band clamp. Different clamps have varying apex sizes, even with the same diameter. Additionally, the gasket thickness is an important part of ensuring a tight seal. Manufacturers design these clamps meticulously to ensure a proper seal.

Therefore, it’s very important that you purchase replacement v-band clamps and gaskets that are an “exact fit” and meet the OEM specifications. It is also crucial to follow recommended installation procedures to maintain this seal and avoid exhaust leaks.

#2 – Proper Installation Procedure for DPFs

One of the more common mistakes we see technicians make when installing a DPF is using a 3/8” or 1/2” air gun to tighten the clamps. What is strange about this is that we rarely see a technician do this on a turbocharger clamp and yet they commonly make this installation mistake with the DPF.

Follow these steps to ensure the proper installation of a DPF Clamp:

Step 1. Install new gaskets on the inlet and outlet side. These are pressed in by hand.

Step 2. Slide the DPF in place and align the DPF and the v-band clamp on the inlet side ensuring there are no gaps.

Step 3. Apply a small amount of heat-rated anti-seize to the threads of the v-band clamp then install the nut by hand or with a rachet and socket. Do not over-torque the v-band clamp. Make sure the v-band clamp is properly seated on the flange into the apex of the v-band clamp. You can use a small rubber mallet to get the v-band clamp to seat properly. Tighten the nut to the manufacturer’s torque specs, tap again to make sure it is seated properly, and then retorque.

Step 4. Repeat steps 2 & 3 for the outlet end.  In the case of a Freightliner one box, make sure the DPF is aligned on the outlet side as well. It is normal to have a small gap on the outlet side. That is what the dual-band clamp is for, to seal that gap. Tighten all bolt nuts slowly and securely, but do not over-torque.

Step 5: Run a regen and then re-torque again.

DPF Clamps: How to Prevent Exhaust Leaks

#3 – Exhaust Leaks from Improperly Installed DPF Clamps Cause Lots of Problems with the Emissions System

Exhaust leaks from improperly installed DPF clamps allow pressure and heat to escape the system diminishing the ability of the emission system to push the soot through the DOC, DPF, and finally the SCR.

Heat loss in the emission system will affect the ability of the system to oxidize the soot collected in the DPF.

Why is this important?

Today’s emission systems are highly engineered to control and process the emissions coming from the engine. Leaks can lead to more frequent manual or forced regens, face plugging, and increased DPF cleaning.

When Should You Replace the DPF Clamps and Gaskets?

When Should You Replace the DPF Clamps and Gaskets?

There are occasions when a DPF has been removed when the system is being diagnosed for issues or to perform regular maintenance. Many technicians want to know if they can reuse DPF clamps and gaskets in those situations.

The short answer is MAYBE.

If the clamps and gaskets are relatively new, and they were not damaged when removed, it is possible to reuse the clamps and gaskets. It is important to make sure that the v-band clamp is wire brushed, and cleaned with penetrating oil to remove any contaminants which will interfere with ensuring a tight seal is maintained when reinstalled.

Typically speaking though we recommend that clamps and gaskets are replaced every time the DPF is removed. The cost of the clamps and gaskets is minimal compared to the cost of unscheduled downtime caused by exhaust leaks.


This article contains insights pulled from 2 of our Quick Tips video series.

Visit the Quick Tips page to see more of these videos.

Buy Aftertreatment Replacement Parts from Redline Emissions Products Dealers

There are 5 compelling reasons you should ask for our aftertreatment replacement parts by name:

Quality: OEM replacement “exact fit” and quality with an industry-leading warranty.

Selection. We provide you with access to a wide selection spanning multiple manufacturers and brands so you can get everything you need from one supplier.

Availability. We have large inventories in multiple warehouses in the US and Canada ensuring quick access to any parts you require.

Packaging. Our products are packaged with all the OEM numbers and cross-references printed clearly on the packaging. Our parts are packaged individually to protect them from being damaged when stocked in the warehouse or in transit.

Training. We provide industry-specific training and education for our dealers’ and distributors’ parts and salespeople so that they can answer your questions and help you make the best choices when buying aftertreatment replacement parts.

Additionally, we provide all our customers with technical support. Call us today to get started.

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.

Want to find out about becoming a Redline Emissions Products® dealer?

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

Like this content? Be sure to like and follow our social media pages. Message us and we’ll return the favor!