Overflow tanks - The fat boy
Overflow tanks - The fat boy
Overflow tanks - The fat boy
Overflow tanks - The fat boy

Overflow tanks - The fat boy

$105.00
  • 3" diameter for more volume
  • Brass construction with a dome top to dress it up
  • Black paint to match the radiator
  • If you would like the site glass add the quantity to the cart when ordering
  • Made in the USA
Should the system pressure exceed the cap’s rating, the spring will compress and fluid will flow through the upper tube to fill the chamber.


In the event the recovery tank reaches capacity, the fluid will find the second tube and exit to the street.  A vacuum will draw the coolant back into the cooling system as the engine cools down.

Contact us directly for alternative sizes, finished or shapes.

We make to order. Please allow adequate time for us to build.

Build time estimates [Oct. 2023]

Brass Model Ts 4 months 

Black Model Ts FT 6 weeks - RT is 5 months

Model As 3-4 weeks

Heater cores 3 weeks

Common street rods 3.75 months

Tricky customs & restorations 4 months

We appreciate your patience as we continue to recruit and train new fabricators.