Skyline RB30 RB26 RB25 Neo RB20 Coolant Heater Hose Upgrade kit – Replacement

RB Heater Hose & Outlet Upgrade Kit

Upgrade the factory heater hose and outlet system on your Nissan Skyline RB with a more durable, corrosion-resistant solution. Designed to replace ageing rubber hoses, plastic fittings and rust-prone factory outlets, this Boost Doc kit uses CNC-machined adapters, braided hoses and high-quality Speedflow fittings.

Suitable options are available for R32, R33, R34 and selected Silvia RB-engine applications.

Key benefits

• CNC-machined components for improved durability
• Corrosion-resistant hose and fittings
• Designed to reduce common coolant-leak points
• Multiple kits available to suit different RB/Skyline applications

Replaces part numbers

• 14075-75T05
• 1407562S01
• 1407575T05
• 92412-21U00
• 92401-75T00
• 92400-24U00
• 27140-15U00

Billet Heater Core Outlet Upgrade

The billet heater core outlet replaces fragile factory components with a stronger, more durable setup designed for RB-powered Nissan applications.

✅ Custom CNC-machined billet aluminium outlet
✅ High-quality Speedflow AN fittings for a secure, leak-proof connection
✅ Banjo fittings keep hoses neatly tucked against the firewall for a clean engine bay

Available Kits:

🔹 Kit #1 — R33 / R34 Skyline, GTS, GTS-T, GTT, GTR, C33 & C34

• Speedflow PVC-coated hose with crimped hose ends

🔹 Kit #2 — R32 Skyline, R32 GTR 

• Deletes sensor 27724-05U00
• Sensor can be retrofitted to the billet heater core outlet
• Sensor wires can be extended for mounting under the dash

🔹 Kit #3 — S14 & S15 with RB engine swap

🔹 S13 LHD & RHD with RB engine swap

Designed for RB-powered S14 and S15 applications.

These kits provide a cleaner, more durable heater-system solution for compatible RB-powered Skylines and Silvias.

Heater core note: The replacement heater core fits many Nissan applications, including many R32 and R33 models and selected S-chassis applications. Measure and confirm suitability before purchasing.

The standard kit is available in black only.

Worldwide shipping available.

🔥 Order Now & Upgrade Your Heater System Today!

Looking for more RB cooling upgrades? Browse our RB Cooling Parts & Kits collection.

Fitting Overview

• Remove the glove box.
• Responsibly de-gas the A/C system. Most A/C shops can do this for a minimal fee.
• Remove the A/C box from the vehicle and cap/bung the hoses and core to keep them clean.
• Access is then available to the heater core and outlets from the passenger footwell.
• Check the condition of the heater core.
• Replace the relevant parts and reassemble in reverse order.

If the billet outlets need to be centred in the firewall grommets:
The heater box assembly is mounted on three sliding studs/screws. Two are located on the passenger side — one low near the carpet line and one higher under the dash. The third is on the driver’s side above the clutch-pedal area.

Loosen all three slightly, centre the outlets in the firewall grommets, then retighten them. Most vehicles will not require this adjustment.

Most A/C technicians can store the refrigerant while the work is completed and then re-gas the system afterwards. Confirm this with your technician before starting.

Heater Tap / Flow Reducer

The component shown in the photos functions as a flow reducer rather than a conventional heater tap. Its purpose is to assist the A/C system during hot start-up by helping deliver maximum cooling more quickly.

Some owners choose to remove this feature without reporting issues; however, fitment requirements vary by vehicle.

Before installing the thermoset adapter block:

• Clean and inspect all components
• Confirm the selected fitting configuration suits your cooling system
• Check hose routing and clearance
• Ensure all fittings are correctly tightened and sealed before operating the engine
• Chamfer the leading edge of the port in the engine block, a small chamfering tool works very well here.
  
• Check and confirm that the angle of the fitting before you install it, you cannot rotate the fitting once it is installed.
• Put the fitting in the freezer for 20-30min to assist the fitment
  
• Use a very thin smear of engine gasket sealant to assist cool sealing.
  
• Be very sure that when installing the fitting, that the fitting is always square to the port, otherwise it will likely gall up the fitting and or possibly create a leak point, or not install at all. The fitting is aluminum, the block is cast iron, the block will mangle the fitting if it is not installed correctly. 

Important: It is the fitter’s responsibility to clean and inspect all parts before installation.

Link to Fitting Instructions

Important Fitment Note

This kit does not directly suit some models with certain heater-tap designs. On these vehicles, the heater taps may need to be omitted/deleted. According to the existing Boost Doc fitment information, this does not change normal hose-kit, heater or A/C operation.

R32 GTR: The rear hose sensor wiring can be extended and the sensor fitted to the billet heater core outlet. This allows the sensor system to remain in use while helping tidy the engine bay.