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Austin Healey Expansion Tank Kit BN1-BJ8

Big Healey
Part no:
CHT142T
Product name:
Austin Healey Expansion Tank Kit BN1-BJ8
Additional information:
Description:

Developed to manage Big Healey coolant overflow

Big Healeys can push coolant out through the overflow during hot running, traffic use or heat soak, especially when the cooling system is working hard. Universal overflow bottles can look out of place and often need adapting, so this kit was developed around the Big Healey engine bay and cooling layout.

The result is a polished aluminium expansion tank kit that catches overflow and allows coolant to return as the system cools, helping reduce fluid loss without making the installation look improvised.

Austin Healey expansion tank kit for BN1-BJ8

This Austin Healey expansion tank kit is suitable for all Big Healey models from BN1 to BJ8, covering Austin Healey 100, 100/6 and 3000 cars. Part of the CapeSport performance range, the tank is handmade in the UK from polished aluminium and suits both right-hand-drive and left-hand-drive cars.

  • 100: BN1, BN2
  • 100/6: BN4, BN6
  • 3000: BN7, BT7, BJ7, BJ8
  • RHD/LHD: both supported
  • Quantity: one kit per car

How it helps reduce coolant loss

  • Catches coolant overflow instead of allowing it to discharge onto the ground
  • Allows coolant to return to the system as the engine cools
  • Helps manage coolant loss during expansion and heat soak
  • Polished aluminium tank gives a neat engine-bay appearance
  • Supplied as a complete kit with tank, cap, hose, bracket, fixings and instructions

Cooling-system condition still matters: an expansion tank helps manage overflow and recovery, but it will not cure overheating caused by issues such as a blocked radiator, failing water pump, incorrect pressure cap, trapped air, head gasket problems or other cooling-system faults. For broader diagnosis and prevention advice, see the Austin Healey cooling guide.

What is included?

  • Polished aluminium expansion tank
  • Replacement radiator cap
  • Mounting bracket
  • Black coolant hose
  • Hose clips
  • Fixings and spacers/washers
  • Printed fitting instructions

Installation notes

Careful hose routing and a good radiator cap seal are important for effective coolant recovery. The tank should be mounted securely with adequate clearance from exhaust heat and moving components.

  • Allow the cooling system to cool before installation
  • Check the radiator filler neck and overflow outlet condition
  • Avoid tight hose bends or restricted routing
  • Recheck coolant level after the first full heat cycle
  • Cars with replacement radiators, electric fans or other cooling modifications may need additional clearance checks

Download Fitting Instructions (PDF)

STOPS FLUID LOSS. REFILLS THE SYSTEM


Cape Sport Logo

Application:
BN1 - BJ8
Quantity per vehicle:
1
Items Per Pack:
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Your Price:
£197.85 Exc VAT
£237.42 Inc VAT
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Frequently Asked Questions

Can this be fitted to a car with an uprated radiator or electric fan?
Yes, but modified cooling systems should be checked carefully before installation. Confirm the tank position, hose routing, radiator cap seal and clearance from heat, moving parts and sharp edges before final fitting.
Does it fit both right-hand-drive and left-hand-drive cars?
Yes. The kit suits both RHD and LHD Big Healey models from BN1 to BJ8. Check clearance and hose routing carefully on cars with modified cooling systems.
What is included with the expansion tank kit?
The kit includes the polished aluminium expansion tank, replacement radiator cap, mounting bracket, black coolant hose, hose clips, fixings, spacers/washers and printed fitting instructions.
Will this expansion tank kit fit my Austin Healey BN1?
Yes. This expansion tank kit is suitable for all Big Healey models from BN1 to BJ8, including BN1 and BN2 four-cylinder Austin Healey 100 models.
Will this stop my Big Healey from overheating?
No. It helps manage coolant overflow and recovery, but it will not cure the cause of overheating. Radiator condition, water pump performance, pressure cap sealing, trapped air and head gasket condition should still be checked if the car is running hot.

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