Four-Layer Silicone Construction
Mishimoto constructs the MMHOSE-RAM-03DRD kit using high-grade silicone reinforced with four layers of heat-resistant fibers.
This layered construction provides improved resistance to temperature, cooling-system pressure and repeated engine heat cycles compared with deteriorated factory rubber hoses.
Mishimoto lists a maximum temperature rating of 330°F, making the kit appropriate for properly maintained stock and modified Cummins cooling systems.
Silicone hoses won’t repair a clogged radiator, weak water pump or combustion leak. They’re better hoses, not a Cummins exorcism kit.
Published Hose Dimensions
Mishimoto lists the following measurements:
Hose 1
- Inner diameter: 1.6 and 1.8 inches
- Outer diameter: 2.0 and 2.2 inches
Hose 2
- Inner diameter: 1.8 inches
- Outer diameter: 2.2 inches
The varying dimensions reflect the molded connection points. Measurements should not be interpreted as a single diameter running uniformly across each hose.
Product Features
- Direct fit for compatible 2003–2010 Dodge Ram Cummins trucks
- Supports 5.9L and 6.7L Cummins applications
- High-grade silicone construction
- Four layers of heat-resistant reinforcing fibers
- Maximum temperature rating of 330°F
- Increased heat and pressure tolerance
- Retains factory-style routing
- Suitable for towing and modified diesel applications
- Red engine-bay finish
- Backed by the Mishimoto Lifetime Warranty
Vehicle Fitment
Make: Dodge
Model: Ram heavy-duty trucks
Model years: 2003–2010
Engines: 5.9L and 6.7L Cummins turbodiesel
Color: Red
Manufacturer part number: MMHOSE-RAM-03DRD
Always verify the exact truck, engine and manufacturer part number before purchase. Aftermarket radiators, engine conversions and custom coolant-routing changes may affect compatibility.
Why Replace Cummins Coolant Hoses?
Coolant hoses experience temperature changes and system pressure every time the engine warms and cools. Diesel towing and modified performance applications can place even greater demands on the cooling system.
Factory rubber hoses can eventually:
- Crack near the fittings
- Become soft or swollen
- Harden from repeated heat cycles
- Develop coolant seepage
- Separate internally
- Collapse under changing coolant flow
- Rub against nearby components
- Become contaminated by engine oil or fuel
A hose can deteriorate internally without displaying an obvious external crack. If the truck’s hose age and maintenance history are unknown, replacement is reasonable preventative maintenance.
Built for Work and Modified Trucks
The Cummins platform is commonly used for towing, hauling and performance builds. Those applications increase cooling demand, particularly during sustained climbs, low-speed operation and hot weather.
The Mishimoto silicone kit is suitable for:
- Daily-driven Ram diesels
- Tow vehicles
- Commercial trucks
- Modified Cummins applications
- Pulling trucks
- High-mileage diesel pickups
- Upgraded radiator installations
- Cooling-system restorations
A stronger hose cannot increase radiator capacity or correct inadequate airflow, but it removes aging rubber from several critical coolant connections.
Red Silicone Adds an Engine-Bay Accent
The red finish creates a visible contrast against the Cummins engine and surrounding black components. It works particularly well with upgraded aluminum radiators, intercoolers and other aftermarket cooling hardware.
Owners seeking a more subdued appearance can select the corresponding black version, while blue is also available. Color does not change the intended performance, despite generations of automotive advertising suggesting that red parts must be faster.
Installation Overview
Never remove a coolant cap or hose while the engine is hot. Diesel cooling systems retain substantial heat and pressure after shutdown.
Basic installation steps include:
- Allow the engine to cool completely.
- Place a suitable drain container beneath the truck.
- Drain the cooling system according to the factory procedure.
- Remove the original hoses without damaging the fittings.
- Compare the new and original hose routing.
- Inspect the radiator necks and engine connections.
- Clean old coolant residue and corrosion from each fitting.
- Install the Mishimoto hoses without twisting them.
- Position every clamp behind the raised bead on its connection.
- Refill the system with the correct coolant.
- Bleed trapped air according to the appropriate service procedure.
- Bring the engine to operating temperature.
- Inspect every connection for leakage.
Recheck the coolant level after the engine cools. Inspect clamp position and hose clearance again after several complete heat cycles.
Complete the Cooling-System Inspection
While the coolant is drained, inspect the rest of the system for:
- Cracked radiator tanks
- Damaged radiator fins
- Water-pump leakage
- Thermostat problems
- Weak or damaged clamps
- Coolant reservoir cracks
- Heater-hose deterioration
- Fan and fan-clutch operation
- Belt wear
- Oil or fuel contamination
- Incorrect coolant mixture
A thermostat that opens too early can prevent the engine from reaching its proper operating temperature. For related diagnostic information, review our guide to the P0128 coolant thermostat code.
Why Choose the Mishimoto Cummins Hose Kit?
The MMHOSE-RAM-03DRD kit offers a direct replacement for aging rubber hoses on compatible 5.9L and 6.7L Cummins trucks.
Its four-layer silicone construction increases heat and pressure tolerance, while the 330°F maximum temperature rating supports demanding diesel applications. The red finish adds a clear visual upgrade, and the Mishimoto Lifetime Warranty provides long-term product coverage.
Additional truck cooling parts and diesel-performance components are available through Pro Street Online. Installation guides and diagnostic articles can be found at My Pro Street.


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