BMW 4 Series F32 F33 F36 Braided Brake Lines Hoses Kit Front & Rear (2013-2019) – Stainless Steel Performance Brake Pipes/Flexi Hoses Upgrade, PTFE, LCI Facelift – HEL Performance 420i 430i 440i – BMW-4-639

BMW 4 Series F32 F33 F36 Reinforced Brake Hose Set - Front and Rear - Part Number BMW-4-639

Give your 4 Series the stopping power and pedal response it deserves. This HEL Performance front and rear braided hose package replaces the factory rubber flexi lines with a PTFE-lined, stainless braided setup that resists expansion under pressure for a firmer, more consistent pedal. Ideal for fast road and track day use on F32 Coupe, F33 Convertible and F36 Gran Coupe models, including LCI facelift cars across 420i, 430i and 440i variants.

If you are chasing sharper pedal bite, better modulation and repeatable braking lap after lap, BMW-4-639 is a proven upgrade. We run these on our own cars and customer feedback is consistently positive for control, confidence and feel. Choose your preferred hose colour, bolt on and enjoy an immediate transformation.

Why this braided hose kit is a must-have upgrade

• Noticeably firmer pedal with reduced line swell compared to ageing OE rubber pipes
• Improved feedback and precision when trail braking or threshold braking
• Stainless fittings and protective PVC outer for durability and corrosion resistance
• Direct-fit flexible lines for front and rear axles - no cutting or custom fabrication
• Confidence-inspiring performance for spirited road driving and track days
• Backed by the manufacturer’s lifetime warranty for peace of mind

Technical details

• Part number: BMW-4-639
• Inner hose: PTFE
• Braid and fittings: Stainless steel with protective PVC cover
• Operating temperature: -70°C to 260°C
• Internal diameter: 3.5 mm
• Outer diameter: 7.5 mm
• Max working pressure: 290 bar
• Burst pressure: 870 bar
• Minimum bend radius: 38 mm

What you receive

• Complete front and rear braided flexible brake line set
• Stainless banjo bolts where required
• Copper crush washers where required
• Lifetime warranty keyring fob
• Installation leaflet

Vehicle compatibility

• BMW 4 Series F32 Coupe 11/2012 to 02/2017
• BMW 4 Series F32 LCI Coupe 05/2016 to 12/2019
• BMW 4 Series F33 Convertible 03/2013 to 02/2017
• BMW 4 Series F33 LCI Convertible 05/2016 to 12/2019
• BMW 4 Series F36 Gran Coupe 07/2013 to 03/2017
• BMW 4 Series F36 LCI Gran Coupe 05/2016 to 12/2019
• Engine options: 420i, 430i, 440i

Fitting and support

Professional installation is recommended. For supply and fitting, contact MJ Modifications in Warwickshire for a quote at info@mjmodifications.co.uk. We are happy to advise on brake fluid choices and setup for fast road or track day use.

Buy with confidence

We have fitted and used this kit on our own BMW builds and on countless customer cars. The result is a firmer pedal, clearer feedback and more predictable braking performance. Add BMW-4-639 to your basket, pick your colour and enjoy a genuine seat-of-the-pants upgrade the first time you press the middle pedal.

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