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Silicone Coolant & Heater Hose
Silicone hose for heat that kills rubber
Coolant, radiator, heater and charge air hose in silicone, across straight lengths, elbows, reducers and hump sections. Stocked at both Long Island counters alongside the clamps that suit it, because the wrong clamp undoes the point of the hose.
Why Silicone
It survives heat that finishes rubber
Rubber coolant hose does not usually fail from pressure. It fails from years of heat cycling, which hardens it from the inside until it goes glassy and splits, normally at the worst possible moment and usually somewhere that empties the cooling system in under a minute.
Silicone does not age that way. It holds its flexibility across a far wider temperature range than rubber and shrugs off ozone and weathering, which is why it turns up on anything running hot, anything asked to last, and anything sitting in an engine bay with no airflow.
The trade is oil. Standard silicone is not oil resistant. Put it on a line carrying oil, fuel or a system with meaningful oil carry-over and it swells, softens and gives up faster than the rubber it replaced. On turbo charge air piping, where a small amount of oil mist is normal, a fluoro-lined silicone is the version to ask for.
Which is the whole decision in a sentence. Heat, cold and long life point to silicone. Anything oily points somewhere else, and it is worth saying what the line carries before choosing.
Temperature
What survives at your temperature
Drag the marker to the temperature your line actually sees, including the hot soak after shutdown rather than the running figure. Ranges are typical and vary by compound.
A typical coolant system sits in this band. Rubber will do the job, and silicone earns its place on how long it keeps doing it rather than on whether it copes today.
Temperature is only half the decision. What runs through the line matters just as much, and standard silicone is the wrong answer on anything oily regardless of how well it handles the heat. Tell us the fluid and the peak temperature together and the choice makes itself.
Construction
Ply count is the spec that matters
Silicone hose is rated by how many layers of reinforcing fabric are laid into the wall. More plies means more pressure and a stiffer hose, and a thick wall with few plies is not the same thing.
Two ply
Low pressure work. Heater lines, overflow and vent runs, and anywhere the hose needs to bend more than it needs to hold pressure.
Three ply
The general purpose choice across most coolant and radiator work on cars and light trucks. Covers the majority of what comes across the counter.
Four ply
Heavier duty coolant circuits, larger engines and charge air piping where boost pressure is part of the picture rather than an afterthought.
Five ply
The top of the range. High boost charge air and heavy equipment cooling, where the hose has to resist both pressure and being stood on.
Where It Goes
Six lines that suit it
Radiator hose
Upper and lower runs, usually the hottest hose on the vehicle and the one whose failure strands you fastest. Silicone here is about outlasting the heat cycling rather than surviving one hot day.
Heater hose
Smaller bore, tight routing, and often buried where replacing it is an afternoon rather than an hour. Worth doing once in a material that will not need doing again.
Charge air and intercooler
Turbo and supercharger piping carrying hot compressed air, frequently with a trace of oil mist in it. Ask for the fluoro-lined version here rather than standard silicone.
Hump and flex sections
The concertina in the middle absorbs engine movement and covers a misalignment that a straight length would fight. Common on swaps, repowers and anything relocated.
Reducers and step-downs
Where a radiator outlet and an engine inlet were never the same size, which is most retrofits. One reducer replaces a pair of adapters and a hose clamp sandwich.
Plant and equipment cooling
Generator sets, pumps and machinery running continuously in hot rooms. The same reasoning as a vehicle, over a much longer duty cycle. See industrial hoses for the wider range.
The Detail Everyone Misses
The wrong clamp ruins the right hose
Worm gear clamps cut silicone
The slots in a standard worm drive band bite into a silicone wall as it is tightened, and silicone is softer than the rubber those clamps were designed around. Over a few heat cycles the band works its way in and the hose starts weeping under a clamp that looks perfectly tight.
Lined worm clamps with a smooth inner band, or T-bolt clamps that spread the load evenly, are the right answer. We stock both alongside the hose rather than treating them as an afterthought.
Fit it clean and fit it once
Silicone grips well but it is not self-sealing on a scored or corroded neck. Clean the pipe, check the barb, and set the clamp behind the bead rather than on top of it. Over-tightening does not compensate for a rough surface, it just accelerates the cutting.
Clamps, T-bolts and protective sleeving all sit on hose accessories and fittings.
Before You Buy
Common questions
No, not standard silicone. It is excellent on heat and poor on hydrocarbons, so it swells and softens on fuel and oil lines and fails sooner than the rubber it replaced. For charge air piping with oil mist in it there is a fluoro-lined version, but for a fuel line the answer is fuel hose, covered on brake, fuel and power steering.
The number of reinforcing fabric layers built into the wall. It determines pressure capability and stiffness, and it is a better guide than wall thickness because a thick wall with few plies is weaker than a thinner one with more. Three ply covers most coolant work, four and five go on boost and heavy duty circuits.
Lined worm clamps or T-bolt clamps. A standard worm drive band has open slots that bite into the softer silicone wall and eventually cut it, which produces a weep under a clamp that still feels tight. We sell both types alongside the hose because it is the most common reason a good silicone install leaks.
On anything running hot, buried where replacement is painful, or expected to stay in service for years, yes. On a low duty line that is easy to reach and cheap to redo, rubber is a reasonable choice. The value is in not doing the job again rather than in surviving today.
Straight silicone is sold by the foot and cut to whatever length you need. Elbows, reducers, humps and T-pieces come as moulded shapes and are bought as the piece. Bring the old hose or the measurements and the routing will decide which combination is simplest.
Yes. Generator sets, pumps and machinery cooling in hot plant rooms use the same reasoning as a vehicle over a longer duty cycle. For operations replacing the same sections on a schedule we hold the specification on file and can build ahead. Ask at either counter or through the contact page.
Get It Matched
Tell us the fluid and the heat
Those two answers decide the material and the ply count between them. Bring the old hose or the measurements to either counter and take the clamps at the same time.