Leak-Free Welsh (Freeze) Plugs for Cummins Engines

Factory welsh plugs are a known weak point on Cummins engines. Under increased boost and cylinder pressure, they can leak, loosen, or completely blow out—often resulting in coolant loss, downtime, and costly repairs.

Our Leak-Free Welsh Plug is engineered to permanently eliminate that problem. Precision-machined from billet materials and supplied with premium sealing hardware, it provides a robust, serviceable solution for 4BT, 12 Valve 6BT, 24 Valve ISB, and 6.7L Cummins engines.

How Many Plugs Do I Need?

Each purchase includes one complete Welsh Plug assembly.

Required quantity per engine:

• 4BT Cummins → 1 Plug

• 24 Valve ISB / 6.7L Cummins → 2 Plugs

• 12 Valve 6BT Cummins → 3 Plugs

Please ensure you order the correct quantity for your engine.

Why Choose EPC Leak-Free Welsh Plugs?

✅ Billet Construction
Precision-machined for maximum strength, durability, and long-term reliability.

✅ Premium Sealing System
Supplied with copper sealing washers and high-temperature Viton O-rings for exceptional sealing performance.

✅ Built for High-Boost Applications
Designed to withstand the pressures that commonly cause factory welsh plugs to fail.

✅ Corrosion-Resistant Hardware
Includes premium stainless steel hardware for long service life in harsh operating conditions.

✅ Serviceable Design
Unlike factory welsh plugs, our design can be removed, inspected, and reinstalled when required.

What's Included?

Each Welsh Plug includes:

• 6061 Billet Leak-Free Welsh (Freeze) Plug

• 316 Stainless Steel Coolant Gallery Bar

• Copper Sealing Washers

• High-Temperature Viton O-Ring

• Stainless Steel Fastening Hardware

Whether you're building a high-horsepower street truck, competition vehicle, tow rig, or dependable workhorse, EPC Leak-Free Welsh Plugs provide the confidence and reliability your Cummins deserves.

Leak-Free for Life.

A strong Shopify addition would be a bold callout immediately under the title:

⚠️ This listing is for ONE Welsh (Freeze) Plug. Most engines require multiple plugs. See the quantity guide below before ordering.