Coolant Bypass Kits for Cummins 5.9 and 6.7 Diesel Trucks

What This Coolant Bypass Kits Collection Covers

The collection is centered on Cummins coolant bypass systems and related fittings. A bypass kit adds a controlled coolant path to support more consistent circulation in the rear of the engine, with parts selected for specific engine generations and transmission configurations.

Application Specific Fitment

Use the application information on each product page to match the part to the exact vehicle or engine. Small differences in year, engine, trim, connection location and accessory layout can change fitment.

Materials and Design

Braided lines, billet fittings, brackets and application specific housings make routing and service more manageable. System layout differs among 12 valve, VP44 and common rail engines, so a kit must match the engine generation and vehicle packaging.

Built for Real World Service

Choose components with the required temperature resistance, mounting method and finish for the intended street, track, off road or towing use.

Fitment and Installation

Verify model year, 5.9L or 6.7L engine, transmission type and existing cooling modifications. Allow the engine to cool fully, follow the kit instructions, refill with the correct coolant mixture and bleed air from the system before driving.

Plan the Complete Job

Review every related gasket, clamp, fastener, fluid or tool before beginning. A complete plan reduces downtime and helps protect the investment in the vehicle.

Top Coolant Bypass Kits Brands

• Fleece Performance for Cummins coolant bypass kits
• Sinister Diesel for diesel cooling upgrades
• Mishimoto for performance cooling products
• Deviant for diesel truck accessories
• Wehrli Fabrication for Duramax and Cummins fittings
• Fleece Performance for service kits and brackets

How to Choose the Correct Coolant Bypass Kits

• Confirm the exact Cummins engine generation
• Match 5.9L or 6.7L application
• Check manual or automatic transmission fitment
• Identify 12 valve, VP44 or common rail configuration
• Verify thermostat housing and auxiliary port needs
• Review included hose and fitting count
• Inspect space around the exhaust manifold
• Use the specified coolant and refill method
• Check clamps and fittings after heat cycling
• Inspect for leaks before towing or heavy use

Common Questions

What is a Cummins coolant bypass kit?

A coolant bypass kit adds a managed coolant flow path for specific Cummins diesel engines using application matched hoses, fittings and brackets.

Will one bypass kit fit every Cummins engine?

No. Confirm the year, 5.9L or 6.7L engine, generation and transmission configuration before ordering.

Do coolant bypass kits include all hardware?

Kit contents vary. Review the product listing for hoses, fittings, brackets, clamps and service parts included.

Can I install a bypass kit at home?

An experienced home mechanic can install many kits with proper tools, cooling system knowledge and careful leak checks.

Do I need to drain the coolant?

Most bypass installations require coolant service. Follow the kit directions and dispose of used coolant responsibly.

What coolant should I use after installation?

Use the coolant specification recommended for the truck and verify the correct concentration for the climate and application.

Will a bypass kit fit with aftermarket turbos?

Clearance can vary with turbo, manifold and piping changes. Check the product notes and engine bay routing before ordering.

How do I bleed air from the cooling system?

Follow the vehicle and kit procedure, refill slowly, allow the thermostat to open and recheck the coolant level after cooling.

Can I reuse old hoses and clamps?

Replace worn hoses and clamps. A bypass kit relies on secure connections to prevent leaks under operating pressure.

How often should bypass hardware be inspected?

Inspect hoses, fittings and clamps during routine service and after the first heat cycles following installation.

Why Buy Coolant Bypass Kits from Black Ops Auto Works

Black Ops Auto Works stocks 24 Coolant Bypass Kits SKUs with real fitment data, competitive pricing and support from staff who build these vehicles themselves. Products are filterable by year, make, model, trim, engine and drivetrain to confirm the correct application before ordering.

For focused shopping, browse our coolants, coolant reservoirs, radiator hoses, water pumps, thermostats, Sinister Diesel, Mishimoto, Fleece Performance.