Fleece Performance Cummins Transmission Heat Exchanger Bypass Plug Kit - FPE-34382

The Fleece Performance Cummins Transmission Heat Exchanger Bypass Plug Kit (FPE-34382) is a purpose-built solution for 2003–2007 Dodge Ram trucks equipped with the 5.9L Cummins diesel engine. Designed specifically for use when installing a coolant bypass kit or when you need to eliminate the factory transmission heat exchanger mounted on the driver's side of the engine, this plug kit gives you a clean, leak-free way to cap off the lines and block port that would otherwise be left open during the bypass process. If you're doing a coolant system upgrade on your 5.9L Cummins, this is the hardware that completes the job correctly.

Key Features & Benefits

• Purpose-Matched for Coolant Bypass Installs: Engineered to work alongside coolant bypass kits on the 5.9L Cummins, so you're not improvising with generic hardware when capping off the factory heat exchanger lines.
• Two Caps + One M16 O-Ring Plug: The kit includes two caps for the heat exchanger coolant lines and an M16 O-ring plug for the engine block — giving you everything needed to seal the system in one package without a separate trip to the hardware store.
• Secure, Leak-Free Seal: The included O-ring plug design helps ensure a reliable seal at the engine block port, reducing the risk of coolant leaks after the heat exchanger is removed from the circuit.
• Works as a Replacement or Upgrade Component: Useful whether you're doing a full coolant bypass build or simply replacing existing caps that have aged or failed on a previous bypass install.
• From a Trusted Diesel Performance Brand: Fleece Performance is a well-known name in the Cummins diesel aftermarket, with a broad product line specifically developed for Dodge/Ram diesel platforms.

Specifications

• Part Number: FPE-34382
• UPC: 732777408726
• Brand: Fleece Performance
• Includes: Two heat exchanger line caps + one M16 O-ring plug for the engine block
• Condition: New
• Shipping Weight: 0.1 lbs.
• Package Dimensions: Approx. 2.0" L × 1.3" W × 0.8" H
• California Prop 65: Yes — California residents, see Prop 65 warning at p65warnings.ca.gov

Fitment

The Fleece Performance FPE-34382 Transmission Heat Exchanger Bypass Plug Kit is designed for:

• 2003–2007 Dodge Ram with the 5.9L Cummins diesel engine

This kit is specifically referenced for use with the factory heat exchanger located on the driver's side of the engine on these trucks. If you are unsure whether this kit applies to your specific build or coolant bypass setup, reach out to the ThreePiece.us team before ordering — we're happy to verify compatibility.

Note: This kit is not confirmed for 6.7L Cummins applications (2007.5 and newer) or earlier 12-valve/VP44 platforms. Verify fitment with our team if your truck falls outside the 2003–2007 5.9L range.

What's in the Box

• 2× Caps for the transmission heat exchanger coolant lines
• 1× M16 O-ring plug for the engine block

Why Buy from ThreePiece.us

• Free Shipping: Every order ships free — no minimum, no surprises at checkout.
• Affirm Financing: Need to spread the cost? Financing is available through Affirm, so you can get the parts you need now and pay over time.
• Expert Fitment Support: Our team has served 10,000+ customers and can help you verify that this plug kit works with your specific coolant bypass configuration. Call us at 813-535-5801 or email sales@threepiece.us.
• Regularly Stocked: The FPE-34382 is a regularly stocked product, so you won't be waiting weeks on a special order for a small but essential piece of hardware.

Frequently Asked Questions

Q: What is this plug kit actually used for?
A: It's used when you're installing a coolant bypass kit on a 2003–2007 5.9L Cummins and need to cap off or plug the factory transmission heat exchanger ports — specifically the two coolant line ports and the engine block port — so the system is properly sealed after the heat exchanger is removed from the coolant circuit.

Q: What exactly comes in the kit?
A: The kit includes two caps for the heat exchanger lines and one M16 O-ring plug for the engine block. This is everything required to plug the heat exchanger ports left open during a bypass install.

Q: Will this kit fit my 2007.5 or newer Ram with the 6.7L Cummins?
A: Based on available information, this kit is specified for 2003–2007 5.9L Cummins applications. We cannot confirm fitment for 6.7L platforms. Contact our team at 813-535-5801 and we'll help you identify the correct part for your truck.

Q: Do I need any other parts to complete a coolant bypass install?
A: This plug kit is a supplemental component designed to work alongside a coolant bypass kit — it does not replace one. You would typically install a full Fleece Performance (or comparable) coolant bypass kit and use this plug kit to properly seal the heat exchanger ports as part of that installation. Contact us if you need help identifying the right bypass kit for your 5.9L build.