Product Overview
Reliable custom rubber parts for industrial applications
Quick Answer
Automotive rubber vent hoses guide air, vapor, or pressure relief flow between vehicle components while providing flexible sealing and vibration compensation.
Automotive Rubber Vent Hose — Precision Molded Breather, PCV & EVAP Hoses for OEM and Aftermarket Supply
Product Overview
Automotive rubber vent hoses are flexible hose components used to route air, vapor, or pressure relief flow between vehicle systems. They are commonly used in crankcase ventilation, fuel tank venting, axle breathers, gearbox breathers, emission control lines, and engine compartment air connections.
A properly designed vent hose helps maintain system pressure balance, supports vapor routing, and provides flexible connection between components exposed to vibration and temperature changes. The hose structure and rubber compound should be selected according to fluid or vapor contact, temperature range, bending radius, installation space, and durability requirements.
What Are Automotive Rubber Vent Hoses?
Automotive rubber vent hoses are molded, extruded, or formed rubber tubes used in vehicle ventilation and breathing systems. Unlike main pressure hoses, vent hoses are usually designed for low-pressure air or vapor flow, but they still need stable sealing, aging resistance, and compatibility with the surrounding media.
Depending on the vehicle system, a vent hose may contact oil mist, fuel vapor, hot air, ozone, water splash, or road contaminants. For this reason, material selection is important. EPDM is often used for weather and heat aging resistance, while NBR or other oil-resistant compounds may be selected for oil vapor or fuel-related exposure.
Key Technical Specifications
| Parameter | Value / Range |
|---|---|
| Materials | EPDM, NBR, CR (Neoprene), ECO (Epichlorohydrin), Silicone (VMQ), FKM |
| Reinforcement | 1-ply polyester fabric; wire helix (anti-collapse) optional |
| Hardness | 50–70 Shore A |
| Operating Temperature | -40°C to +150°C (EPDM); -40°C to +120°C (NBR/CR); -65°C to +200°C (Silicone) |
| Operating Pressure | Low pressure / vacuum (standard); up to 3 bar (reinforced) |
| Inside Diameter | 4 mm to 50 mm |
| Wall Thickness | 2.5 mm to 6 mm |
| Shape | Straight, elbow (45°/90°), S-curve, multi-bend molded |
| End Configuration | Plain cut, bead-rolled, barbed nipple, connector-integrated |
| Fuel / Vapor Permeation | Low permeation ECO/FKM inner liner for EVAP compliance |
| Standards | SAE J30, SAE J2027 (fuel vapor); IATF 16949 capable |
| Compliance | RoHS, REACH; PPAP and material data sheets available |
| MOQ | 100 pcs standard |
Types of Automotive Rubber Vent Hose
PCV (Positive Crankcase Ventilation) Hose
The most common vent hose in the engine system. Routes blow-by gases from the crankcase back into the intake manifold for re-combustion, reducing emissions and preventing crankcase pressure buildup. Continuously exposed to hot oil mist, acidic blow-by gases, and underhood temperatures — requiring NBR or ECO rubber for oil mist and fuel vapor resistance.
Crankcase Breather Hose
Similar to PCV hoses but typically on naturally aspirated engines or as supplementary breather connections. Connects the rocker cover, air-oil separator, or valve cover to the air intake duct or atmosphere. Must resist oil vapor, condensation, and thermal cycling.
EVAP (Evaporative Emission Control) Hose
Connects the fuel tank, charcoal canister (EVAP canister), purge valve, and intake manifold in the evaporative emission control system. Carries fuel vapor (hydrocarbons) under low pressure — ECO (Epichlorohydrin) or NBR with low-permeation inner liner is mandated for EVAP compliance per SAE J2027.
Fuel Tank Vent Hose
Routes fuel vapor and pressure equalization between the fuel tank and the EVAP canister. Must be fuel-vapor impermeable to meet emissions regulations — ECO, FKM-lined, or multi-layer co-extruded construction.
Coolant Overflow / Expansion Tank Vent Hose
Connects the radiator cap overflow port or engine coolant expansion tank to the coolant reservoir. Carries hot coolant vapor and steam — EPDM is the standard material for its superior hot water and steam resistance.
Differential / Gearbox Breather Hose
Vents thermal pressure buildup from transmission and differential housings to atmosphere. Routes away from water crossing areas on 4×4 and off-road vehicles to prevent water ingestion through the breather. Requires oil resistance — NBR or CR standard.
Battery Vent Hose
Routes hydrogen gas and acid vapor away from conventional lead-acid batteries to the vehicle exterior. Requires acid vapor resistance — EPDM or CR compounds.
Turbocharger Oil Drain / Vent Hose
Short sections venting the turbocharger bearing housing oil return and vapor circuits. Operates near high-temperature turbo housings — silicone (VMQ) or ACM for heat resistance above +150°C.
Custom Molded Vent Hose
Produced with bends, steps, branches, or molded end shapes to fit limited installation space and avoid interference with surrounding components.
Material Selection Guide
| Material | Temp. Range | Key Properties | Best Vent Application |
|---|---|---|---|
| EPDM | -40°C to +150°C | Hot water/steam, ozone, UV resistant | Coolant overflow vent, battery vent |
| NBR (Nitrile) | -30°C to +110°C | Oil mist, fuel vapor resistance | PCV hose, crankcase breather, gearbox breather |
| CR (Neoprene) | -40°C to +120°C | Oil + ozone dual resistance | General underhood vent, differential breather |
| ECO (Epichlorohydrin) | -40°C to +120°C | Very low fuel vapor permeation, oil resistant | EVAP hose, fuel tank vent (SAE J2027) |
| Silicone (VMQ) | -65°C to +200°C | Extreme heat, remains flexible | Turbo area vent hoses, high-temp underhood |
| FKM (Viton) | -20°C to +200°C | Highest fuel/chemical resistance | Premium EVAP, aggressive fuel vapor service |
Industries & Vehicle Applications
Julong Rubber automotive vent hoses serve all major vehicle segments and powertrain types:
Marine inboard engines — crankcase vent, fuel tank vent hoses for marine emission compliance
Passenger cars — PCV, EVAP, coolant overflow, battery vent; all fuel types (gasoline, diesel, hybrid)
SUVs & crossovers — larger-bore PCV and EVAP systems for higher-displacement turbocharged engines
Light commercial vehicles & vans — extended-duty PCV and gearbox breather hoses for higher mileage intervals
Trucks & heavy vehicles — diesel crankcase breather systems, differential breather extensions
4×4 & off-road vehicles — extended differential and gearbox breather hoses routed above waterline
Hybrid & electric vehicles — battery compartment vent hoses, thermal management system breathers
Agricultural & construction machinery — engine crankcase breathers, hydraulic reservoir vent hoses
Performance Benefits
Quality rubber vent hoses prevent failures that trigger emissions faults, engine damage, and safety hazards:
Long service life — correctly specified rubber compounds resist oil mist, fuel vapors, and thermal cycling for extended replacement intervals
Emissions compliance — low-permeation ECO/FKM hoses prevent hydrocarbon vapor leakage that triggers EVAP system fault codes (P0440–P0457 range)
Crankcase pressure control — functional PCV hoses prevent oil leaks, oil consumption, and sludge buildup from crankcase over-pressurization
Fuel system integrity — intact fuel tank vent hoses prevent fuel starvation caused by vapor lock and tank vacuum collapse
Drivetrain protection — properly routed 4×4 breather extensions prevent water ingestion into differentials and gearboxes during water crossings
Battery safety — vented battery hoses safely route explosive hydrogen gas away from the passenger compartment
Customization Capabilities
Julong Rubber engineers vent hoses to exact OEM or aftermarket requirements:
Compliance documentation — PPAP, IMDS, SAE J2027 permeation test data, RoHS/REACH declarations on request
3D geometry — complex multi-bend molded hoses matched to underhood routing constraints
Bore and wall — ID from 4 mm to 50 mm; wall thickness optimized for collapse resistance vs. flexibility
End fitting integration — molded barbed nipples, quick-connect collars, bead-rolled ends, OEM-matched connector bosses
Low-permeation inner liner — ECO or FKM inner layer co-extruded with EPDM or NBR outer for EVAP compliance
Anti-collapse reinforcement — steel wire helix for hoses routing through areas with vacuum exposure or risk of mechanical crushing
Compound selection — all major automotive elastomers; hardness and compression set optimized per system duty
Why Source from Julong Rubber?
- ✅ IATF 16949 capable — automotive OEM quality system, PPAP documentation
- ✅ ISO 9001:2015 certified manufacturing and inspection
- ✅ In-house tooling — complex molded hose geometry, 7–20 day lead time
- ✅ Full material range — EPDM, NBR, CR, ECO, Silicone, FKM compounded in-house
- ✅ SAE J2027 / J30 compliance — EVAP and fuel vapor permeation documentation
- ✅ OEM drawing matching — reverse engineering from sample or CAD file
- ✅ Low MOQ — 100 pcs aftermarket; program volumes for OEM
- ✅ 15+ years automotive rubber supply to European and global OEM markets
- ✅ English-speaking technical sales — RFQ response within 24 hours
How to Order / Request a Quote
To prepare an accurate quotation, please provide the drawing, 3D file, sample, or main installation dimensions of the automotive rubber vent hose. Important details include inner diameter, outer diameter, total length, bend angle, branch position, end shape, wall thickness, and connection method.
Please also confirm the application system, such as crankcase ventilation, fuel tank venting, axle breather, or engine air vent. Media exposure, working temperature, vehicle model, quantity, packaging request, and target delivery schedule should also be included.
FAQ
▼ Can you produce automotive rubber vent hoses based on our sample or drawing?
Yes. Custom vent hoses can be produced according to drawings, 3D files, physical samples, vehicle models, or actual installation dimensions.
▼ Which material is suitable for automotive vent hoses?
The material depends on the media and working environment. EPDM is common for air and weather resistance, NBR for oil mist, and ECO may be considered for fuel vapor or emission-related applications.
▼ Can the hose be molded with bends or branch ports?
Yes. The hose can be customized with bends, stepped diameters, molded ends, branch ports, clamp grooves, and connector interfaces to match the installation layout.
▼ Are vent hoses suitable for fuel vapor applications?
Fuel vapor applications require careful material selection and specification review. Please provide the fuel type, temperature, and any permeation or compliance requirement before production.
Request a Custom Quote
If you need automotive rubber vent hoses for vehicle ventilation, vapor routing, or pressure balance connections, you can send the drawing, sample, or installation details for review. The material, hose structure, and manufacturing method can then be matched to the actual vehicle system requirements.
