EVIL ENERGY 5/16" Heater Hose Coolant Radiator Straight

EVIL ENERGY 5/16" heater hose is a 10-foot EPDM coolant line built to SAE 20R3 standards for radiator, overflow and hot-water heater connections, rated 100 PSI working pressure and designed to withstand -40°F to 257°F.

This hose is made for vehicles and cooling systems that need a reliable, heat- and chemical-resistant connection between radiator components, heater cores, and overflow reservoirs. Constructed from EPDM rubber with engineered wall thickness, the tubing offers a balance of flexibility and durability while meeting SAE 20R3 Class D-2 requirements. It suits common engine-cooling media such as water, antifreeze and coolant blends and comes in a 10-foot length to allow custom routing and trimming for a wide range of installations.

How durable is this hose under engine heat and pressure?

The hose is formulated from EPDM rubber and tested to a 100 PSI working pressure with a 300 PSI burst rating, giving a safety margin for typical automotive and small-engine cooling systems. Temperature tolerance spans from -40°F to 257°F so it resists hardening in cold climates and softening in high temperatures. Wall construction surpasses the SAE 20R3 D-2 class standard for enhanced longevity.

• Working pressure: 100 PSI; burst pressure: 300 PSI
• Temperature range: -40°F to 257°F
• Manufactured to exceed SAE 20R3 Class D-2
• EPDM compound resists heat, ozone and common coolants

Will this size fit my radiator, heater core, or overflow connection?

The hose has a 5/16" (8 mm) inside diameter with ±0.4 mm tolerance and a 0.55" (14 mm) outside diameter with ±0.5 mm tolerance, designed for common small-diameter coolant lines. Its 10-foot length provides enough material to cut and custom-fit to your layout, while the minimum bending radius (64 mm) helps prevent kinking when routed tight. Always verify hose ID against your barb, clamp or fitting for a secure, leak-free connection.

• Inner diameter: 5/16" (8 mm) ±0.4 mm
• Outer diameter: 0.55" (14 mm) ±0.5 mm
• Length: 10 feet for flexible routing and trimming
• Min bending radius: 64 mm to avoid kinks

What fluids and environments is this hose compatible with?

Designed for engine cooling systems and hot water heater circuits, this EPDM hose works with water, antifreeze, and standard coolant formulations commonly used in automotive applications. EPDM resists degradation from heat, ozone and many coolant additives, making it a good choice for both seasonal use and long-term engine duty. It is not intended for fuel, oil, or high-concentration solvent exposure.

• Compatible media: water, antifreeze, coolant mixtures
• Resists ozone, heat and most coolant additives
• Not suitable for fuel or oil service
• Suitable for radiator-to-overflow and heater-core connections

How easy is it to install and maintain this heater hose?

Installation is straightforward: measure, cut to length, slide on hose clamps and secure to barbed fittings or spigots. The hose’s flexibility simplifies routing through tight engine bays while maintaining shape within the 64 mm bend radius. Routine visual inspection for cracking, soft spots or leaks keeps the system reliable; replace whenever clamps loosen or the material shows aging.

• Trimable 10-foot length for custom installations
• Use standard hose clamps and barbed fittings
• Inspect periodically for wear, leaks or hardening
• Compatible with routine coolant system maintenance

Who is this for: EVIL ENERGY's 5/16" heater hose is ideal for DIY mechanics, professional technicians and fleet maintainers who need a short-diameter, heat-resistant coolant line for radiator connections, heater cores, overflow tanks and hot water heater systems. Choose this hose when you require a dependable EPDM tube with specified dimensional tolerances, broad temperature range and compliance with SAE 20R3 standards for small-diameter coolant applications.