Replace your aged, cracked, and leaking factory crankcase breather hoses with this premium 5-piece silicone breather hose kit, hand-crafted from multi-ply silicone and nylon-reinforced construction for permanent durability and superior heat resistance. Factory rubber breather hoses on the 1.8T AUM and AUQ engines are notorious for hardening, splitting, and developing vacuum leaks after years of underhood heat exposure — leading to rough idling, oil leaks, increased oil consumption, check engine lights, and persistent vacuum leak codes that frustrate VAG enthusiasts. This silicone replacement kit permanently eliminates the recurring breather hose failure problem with bursting pressure of 245 PSI, temperature tolerance from -60°C to +260°C, and visual presentation that elevates the engine bay aesthetic while delivering genuine functional reliability.

Features:

Premium silicone & nylon-reinforced construction – multi-ply hand-crafted hoses deliver superior heat resistance, pressure handling, and long-term durability compared to factory rubber alternatives
3-ply 4.5mm wall thickness – overbuilt construction ensures structural strength and resistance to deformation under sustained crankcase pressure cycling
Direct factory replacement design – manufactured to exacting OE dimensional specifications for clean, modification-free installation
Wide color selection – available in matte black, gloss black, blue, red, green, white, yellow, pink, purple, grey, and orange to match any engine bay aesthetic
Extreme temperature tolerance – rated for -60°C (-76°F) to +260°C (+500°F) operation, far exceeding factory rubber breather hose limits
High pressure handling – 245 PSI bursting pressure rating with 0.3-0.9 MPa working pressure range provides significant safety margin over factory specifications
Permanent vacuum leak fix – addresses the recurring crankcase ventilation failures that plague aged 1.8T engines

Specifications:

Condition: 100% Brand New
Type: Crankcase Breather Hose Kit
Material: Premium Silicone with Nylon Reinforcement
Construction: 3-Ply (4.5mm) / 4-Ply (5.4mm) Multi-Ply
Wall Thickness: 4.5mm (3-Ply Standard)
Bursting Pressure: 245 PSI
Working Pressure: 0.3 – 0.9 MPa
Temperature Range: -60°C to +260°C (-76°F to +500°F)
Size Tolerance: ±0.5 mm
Quantity: 5 hoses per set
Available Colors: Matte Black / Black / Blue / Red / Green / White / Yellow / Pink / Purple / Grey / Orange
Position: Crankcase Ventilation System
Purpose: Performance Upgrade / OE Replacement / Vacuum Leak Repair

OE / Replacement Part Numbers:

06A 103 213 F / 06A103213F
06A 103 221 AF / 06A103221AF
06A 103 221 AH / 06A103221AH
06A 103 247 / 06A103247
035 103 245 G / 035103245G
035 103 245 A / 035103245A

Fitment:

VW Golf MK4 1.8T: AUM / AUQ engines (1998 – 2006)
VW Jetta MK4 1.8T: AUM / AUQ engines (1999 – 2005)
VW Bora 1.8T: AUM / AUQ engines (1999 – 2005)
Audi A3 8L 1.8T: AUM / AUQ / ARX / ARY engines (2001 – 2003)
Compatible with 1.8T AUM / AUQ / ARX / ARY engine codes only – not compatible with 2.0L, 1.6L, 1.9 TDI, or other engine variants
Confirm vehicle model, engine code, and factory breather hose part numbers before ordering

Benefits:

Silicone construction permanently eliminates the cracking, hardening, and vacuum leak failures that plague factory rubber breather hoses on aged 1.8T engines after 15+ years of underhood heat exposure
Resolves persistent rough idle, vacuum leak codes (P0171 lean fault), oil consumption, and oil weeping issues associated with failed factory PCV breather hoses
Higher pressure rating (245 PSI bursting pressure) provides significant safety margin for crankcase pressure cycling under all driving conditions
Wide temperature tolerance (-60°C to +260°C) maintains hose integrity in extreme cold starts, prolonged hot-climate driving, and sustained high-load operation
Multi-ply nylon-reinforced construction prevents hose collapse under crankcase vacuum cycling – a common failure mode of aged single-ply rubber hoses
Long-term durability eliminates the recurring expense and downtime of repeated breather hose replacement service intervals
Significant engine bay aesthetic upgrade – wide color selection allows engine bay theming to match your vehicle's exterior or build aesthetic
Significant cost savings compared to genuine VAG dealer rubber hoses, with substantially better long-term performance and durability

Installation Notes:

Allow the engine to fully cool before beginning hose replacement to avoid burns from hot engine components
Note the original routing and orientation of each factory breather hose during removal – take photos before disassembly to ensure correct reassembly
Inspect the PCV valve, breather assembly, and intake manifold connections during installation – replace any aged or damaged components to ensure long-term leak-free operation
Use stainless steel T-bolt or worm-drive hose clamps appropriate for silicone hose – silicone requires properly sized clamps to seal effectively
Ensure all connections are fully seated and clamped before starting the engine – improperly seated breather connections will cause vacuum leaks and rough running
After installation, scan for stored fault codes and clear any historical vacuum leak codes (commonly P0171, P2187, or P0507) related to the previous failed breather hoses
Test for vacuum leaks using a smoke test or carb cleaner spray method to verify proper sealing across all connections
Installation instructions are not included with the kit – professional installation is recommended unless you are familiar with VAG 1.8T crankcase ventilation system service procedures
If unsure about compatibility with your specific VW or Audi variant, contact our team with your year, model, and engine code (AUM / AUQ / ARX / ARY) before ordering

Warranty:

12-month standard warranty from date of purchase
Contact our support team for assistance with any issues

VW JETTA MK4 (99-05)