Parts for your 2018 Haval H6-Radiator cap

2018 Haval H6 radiator-cap: what’s fitted and what to service

For the 2018 Haval H6, a traditional radiator cap on the radiator itself isn’t used. Technical references including the 2018 Haval H6 Owner’s Manual (Engine Coolant section), the GWM/Haval H6 Workshop Manual (Cooling System, 2017–2019), and the Haval parts catalogue (EPC, Cooling Group) show a sealed, pressurised expansion tank (degas bottle) with the pressure cap mounted on the reservoir, while the radiator has no filler neck or cap.

Why the change? Modern cooling systems put the pressure cap at the highest point of the system (the expansion tank) to improve air purging and maintain stable pressure. That setup helps reduce hot spots, simplifies bleeding after coolant changes, and keeps hands away from the radiator core. It also packages better in a tight engine bay and supports consistent operating temperatures in turbocharged engines like the H6’s 1.5T and 2.0T.

So, while there’s no “radiator cap” on the radiator, the H6 still relies on a pressure cap — it’s just on the coolant reservoir. That cap controls system pressure, allows excess coolant to vent to the bottle as things heat up, and draws coolant back as the system cools. If the cap can’t hold pressure or seal properly, drivers may see overheating, coolant loss, or collapsed hoses after a cold start.

As part of regular servicing, it’s smart to treat the coolant reservoir cap like any other wear item:

• Only open the cap when the engine is cold, hot coolant can spray under pressure.
• Inspect the cap’s rubber seal and the bottle’s neck for cracks, hardening, or crusty deposits.
• If there are signs of overheating, frequent low coolant, or staining around the cap, pressure-test or replace the cap.
• Top up and bleed the system via the expansion tank only, using the correct OAT/HOAT coolant specified by Haval and demineralised water if mixing.
• Use a genuine or quality aftermarket cap that matches the specified pressure rating for the vehicle’s market.

Bottom line: for a 2018 Haval H6, shoppers looking for a “radiator cap” need the coolant reservoir (expansion tank) cap — that’s the part that does the job.

Popular questions about the 2018 Haval H6 radiator-cap

Does the 2018 Haval H6 have a radiator cap?
No. The H6 uses a sealed, pressurised expansion tank. The pressure cap is on the coolant reservoir, not on the radiator. All coolant filling and bleeding is done via that tank.

Where should coolant be added on a 2018 Haval H6?
Add coolant only through the expansion tank (the translucent reservoir with the pressure cap). Do it when the engine is cold and keep the level between the MIN and MAX marks.

How do you know if the reservoir cap needs replacing?
Watch for repeated coolant loss, overheating in traffic, staining or white crust around the cap, or hoses that collapse after a cold start. Any of these can point to a cap that’s not holding pressure or sealing properly.