Reply to "Jtaphorn Cooling system modification"

Convert the recovery tank into a head tank
(1) Add a tube fitting or nipple to the recovery tank for the bleed from the radiator.
(2) Add a tube fitting or nipple to the recovery tank for the bleed from the system tank.
(3) Increase the size of recovery tank's bottom fitting to 1/2".
(4) Screw a fitting into one of the threaded ports on the side of the coolant pump, 3/8" NPT to 1/2" hose.
(5) Connect the top bleed of the radiator to its new tube fitting or nipple on the recovery tank with hose.
(6) Connect the bottom fitting of the recovery tank to the new fitting on the coolant pump with hose.
(7) Install the 13 psi radiator cap from the system tank onto the radiator cap fitting of the recovery tank.
(8) Raise the height of the recovery tank within the clamp that holds it.
(9) The recovery tank is now a head tank.

Convert the "system tank" into a swirl tank:
(1) Remove the radiator cap fitting from the system tank, block the remaining hole.
(2) Flip the system tank over and add a tube fitting or nipple to the middle of the "top".
(3) Connect the new tube fitting or nipple of the recovery tank to its new tube fitting or nipple on the head tank with hose.
(4) The system tank is now a functional swirl tank.


•Use 1/4" hose for the radiator vent and swirl tank vent
•Use 1/2" hose to connect the "header tank" to the coolant pump suction
•The Flow Kooler coolant pump (and others) have two 3/8" NPT ports that can serve as the connection to the head tank
•The head tank should be clamped in the mounting strap at a height making its mid-point approximately the same height as the highest point in the coolant system. I assume the highest point is the top of the "system tank" aka "swirl tank". Cutting a hole in the cover above the head tank, the same as the OEM hole found in the 1974 models, makes this easier to live with, because the pressure cap on top of the head tank will be accessible through the hole. Cutting the hole in older Panteras is covered in TSB 11, page 3.
•When filling the coolant system, it is best to "top-off" the cooling system when it is hot but with the pressure cap removed (zero pressure on the pump suction), under those conditions the coolant level in the header tank should be no more than half full.

This is also covered in my post on the first page of sticky #2 and other posts.