I don't know if this will help at all but some one sent it to me for a race car. It probably won't apply to your situation but it's all I have.
The radiator cap must be 19 to 22 PSI, and must be a non-vented type cap.
The coolant fill point must be positioned at the highest level in the system and has to be limited to one radiator cap only. This is either on top the existing radiator or with an adapter on the manifold but not both.
The overflow tank, as we presently call it, must be converted to a true recovery or expansion tank. This is an absolute must, and is accomplished by adding or extending a 1/4 inch inside diameter tube from the top of the can to 1 inch from the bottom of the inside surface of the can, and cut at a 45° angle.
Bleed your system of all air. To accomplish this, we have found it best to use the following steps.
Fill the system to capacity, then run the pump, on and off, on and off, etc. Listen for the pump to change pitch as it catches the water.
With the radiator cap secured, run your engine until the temperature gets to 160° and then shut it off.
Let your engine cool down so as not to interrupt the suction recovery process that would occur by removing the radiator cap. After an ample cool down time, repeat the steps above until you are sure all of the air is removed from the cooling system.
If you want to cut down on the time required to do the above procedure, simply purchase or borrow a radiator pressure tester. Mount it to the radiator cap fill point and pump it up to 20 pounds and leave it overnight. The system should not leak down and it will force almost all of the air out of your system.
Your catch can should now contain approximately three inches of coolant This means that the tube you added will be submersed in two or more inches of liquid. Do not, I repeat Do not drain this out. If an air pocket should develop within your engine, this excess liquid will be drawn back in and the air out. If there is no liquid, then air will be sucked right back into the engine and you have gained nothing but more heat. If these procedures are followed, do not remove your cap again. Coolant maintenance is over, not just for this race but for the entire season.