Automotive Vacuum Hose

What Does an Automotive Vacuum Hose Do?

An automotive vacuum hose carries engine vacuum to the accessories and systems that depend on it, so a cracked line can trigger rough idle, hard braking, or a check-engine light. Your power brakes rely on vacuum to run the brake booster, giving you the assist you feel at the pedal. The PCV and crankcase ventilation system uses vacuum to pull blow-by gases back into the intake, which keeps your oil cleaner and your emissions in check. EVAP and emissions controls route fuel vapor through these lines, while ignition advance and transmission modulators read vacuum to adjust timing and shift points. On classic builds, engine vacuum even runs hide-away headlights and cowl induction flaps. If you're chasing an idle problem, review the bad PCV valve symptoms before you start swapping parts. Ready to trace and replace a failing line? Shop All vacuum hose and fittings to match your engine.

Vacuum Hose Materials: Silicone vs. Rubber

Silicone and rubber are the two materials you'll choose between, and the right pick depends on heat, chemical exposure, and budget. Rubber (EPDM or nitrile) is the factory-style choice: it's affordable, flexible, and fine for most under-hood vacuum routing. Silicone handles higher heat and lasts longer, which makes it a favorite for performance builds and tight spots near headers or turbos. Here's how the options compare:

• Rubber vacuum hose: budget-friendly, easy to route, and a direct match for stock replacement and vacuum line repair work.
• Silicone vacuum hose: high-temperature tolerance, longer service life, and bright colors for a clean engine-bay look.
• Reinforced hose: braided or fabric layers add burst strength for boosted and high-vacuum applications.

Brands like Mishimoto build colored silicone vacuum hose for show-quality engine bays, while Gates covers dependable rubber lines for everyday repairs. Match the material to your under-hood temperatures first, then pick the size and color you want.

How to Choose the Right Vacuum Hose Size

Match the hose to your fitting by measuring inside diameter (ID) first, since vacuum hose is sized by the barb or port it slides onto. Slip a hose over a barb and it should feel snug, not loose, so measure the outside diameter (OD) of the barb and choose a hose ID that matches it closely. Common vacuum tubing runs from small 1/8-inch lines for signal ports up to 3/8-inch and larger for brake booster feeds. Check the wall thickness too, because a thin wall can collapse under strong vacuum and a thick wall may not seat on a tight barb. If you're stepping up to threaded connections, our guide to AN fittings and hose sizes explains how the numbering works. For a clean, leak-free assembly, follow how to assemble AN fittings and hose assemblies before you cut and clamp. When in doubt, measure twice and match the hose ID to the barb OD.

Vacuum Hose Types and Applications

Vacuum hose comes in application-specific types, so start with the job and let it guide your choice. Some lines carry oil vapor, others carry fuel vapor or full manifold vacuum, and each has a hose built for it. Here are the types you'll shop most:

• PCV hose: routes crankcase blow-by back to the intake and resists oil and heat.
• Breather and vent hose: feeds fresh air into the crankcase and valve covers.
• Emission hose: handles EVAP and fuel-vapor routing that must resist fuel exposure.
• Brake booster hose: a larger-diameter line built for the steady vacuum your booster needs.
• Silicone vacuum hose kits: assorted lengths and sizes for a full vacuum hose kit refresh.

Dorman offers OE-style replacement lines, while Mr. Gasket and Vibrant Performance cover performance and dress-up options. Need a junction or tee? Shop vacuum fittings and manifolds to split and route your lines cleanly.

Top Vacuum Hose Brands at JEGS

JEGS carries vacuum hose from the brands enthusiasts trust for fitment and durability. For silicone lines and colored engine-bay upgrades, Mishimoto and Vibrant Performance lead the way, while Mr. Gasket brings classic performance styling. For dependable rubber replacement hose, Gates and Dorman keep your daily driver and project car on the road. Buying by brand helps you match quality and appearance across your whole engine bay, so your new lines look and perform like a set. Stock up on a vacuum line repair kit or a full vacuum hose kit and you'll have the right sizes on hand for the next fix. Browse the wider fittings and hose selection to add clamps, tees, and adapters in one order. Ready to finish the job? Shop All vacuum hose and fittings now and get your engine vacuum hose routing back to leak-free.