Outus 3/4" ID Silicone Heater Hose 25ft Coil, Blue — Reinforced, High-Temp Coolant Line

Outus 3/4" ID 25ft silicone heater hose is a durable, high-temperature coolant and radiator hose designed for custom cuts and reliable performance in automotive heating and cooling systems.

This flexible blue silicone hose from Outus is built to replace or upgrade rubber heater lines, radiator bypasses, and various coolant runs. Reinforced with a polyester braid, it resists aging, cracking, and splits while tolerating extreme temperatures and pressures. Supplied as a 25-foot coil, it’s sized to let you trim exact lengths for custom routing in cars, trucks, boats, small engines, and workshop projects.

How will this hose hold up to high temperature and pressure?

The Outus silicone heater hose is formulated to withstand a wide temperature range from -40°F to 400°F (-40°C to 200°C) and working pressures up to 85 PSI (burst 170 PSI). Its silicone matrix and polyester reinforcement combine flexibility with strength so it performs steadily under thermal cycling and elevated coolant temperatures.

• Temperature tolerance from -40°F to 400°F (-40°C to 200°C)
• Working pressure rated to 85 PSI; burst tested to 170 PSI
• Polyester braid reinforcement minimizes expansion and increases durability
• Silicone resists hardening, cracking, and premature aging

Will it fit my vehicle and how easy is installation?

This hose has a 3/4" (19 mm) inner diameter and a 27 mm outer diameter, making it compatible with most heater cores, radiator fittings, and vacuum lines that accept that size. The 25-foot coil allows you to trim to exact lengths without splices, and the material is flexible and kink-resistant for straightforward routing and clamp sealing.

• Inner diameter: 3/4" (19 mm); outer diameter: 27 mm
• Supplied in a 25 ft coil for multiple runs or long custom routes
• Flexible, easy to cut with standard tools and simple to clamp
• Kink-resistant construction provides consistent flow and sealing

Which fluids and environments is the hose compatible with?

Outus silicone heater hose is suitable for coolant, hot water, steam, compressed air, and weak acids/alkalis up to 25%. Its material formulation offers good resistance to common automotive coolants and many thermal media, making it a versatile choice for engine bays and light industrial or marine systems.

• Compatible with engine coolant and hot water systems
• Works with air and steam lines and weak acids/alkalis (≤25%)
• Resists degradation from common automotive fluids and temperature cycling
• Not recommended for strong acids, fuels, or solvents without confirmation

How long will the hose last and what maintenance is needed?

The reinforced silicone construction is engineered for longer service life than typical EPDM rubber hoses, resisting cracks and splits that come from heat and age. Occasional visual inspection and proper clamping at connections are generally all that’s required to keep the hose performing reliably.

• Designed for extended life compared with standard rubber hoses
• Inspect periodically for wear, abrasion, or clamp integrity
• Allow for slight expansion or softening under sustained high heat — normal behavior
• Trim and replace sections as needed for maintenance or routing changes

Who is this for: The Outus 3/4" ID 25ft silicone heater hose is aimed at DIY mechanics, restoration enthusiasts, performance tuners, marine hobbyists, and small-fleet maintenance teams who need a flexible, heat-resistant hose for cooling, heater, or auxiliary fluid lines. If you want a long coil to cut custom lengths, a material that withstands high temperatures, and a reliable alternative to rubber hose for demanding engine bay environments, this product suits those needs without excessive complication.