PRODUCT DETAILS
Honda K20Z3 Bypass Inlet Hose 19504-RAC-000
If you’re going through the cooling system on an 8th gen Civic Si, don’t ignore the little stuff. This Honda K20Z3 bypass hose, Honda 19504-RAC-000 hose, is the coolant bypass hose that keeps coolant moving where it needs to, so your temps stay predictable instead of creeping up at the worst time.
This is a factory K20Z3 hose replacement for the 2006 to 2011 Honda Civic Si K20Z3. After years of heat cycles, the Si K20Z3 rubber hose can go soft, swell, or get brittle, and that’s when you get the annoying slow seep that leaves crusty residue but never drips on the ground. Swap it while you’re in there and you avoid the classic “why is my overflow low again” problem later.
Because it’s molded like the Honda OEM bypass hose, you get a K20Z3 hose direct fit with the right bends, no kinks, no fighting it onto the fittings. That matters for flow and for longevity, since the hose doesn’t sit preloaded or rubbing on something sharp. If you’re doing maintenance, tracking down a leak, or freshening a K series, this civic si bypass inlet hose belongs on the list. We run these same OEM style pieces on our own cars because they fit right and they don’t turn into a science project.
Key Features
- Honda Civic Si K20Z3 hose
- Supports proper circulation in the cooling system hose layout
- Molded rubber shape for clean fit and fewer stress points
- Direct swap for an aging OEM Civic Si bypass hose
- Good call for a K20Z3 engine hose replacement during a coolant service
Fits the following vehicle:
2006–2011 Honda Civic Si (K20Z3)
SKU: OHA-19504-RAC-U00. If you want a no drama fix, this Honda k20z3 inlet hose is the right move. It’s the kind of 8th gen civic coolant hose you replace once and stop thinking about, which is exactly the point.