Coolant Overflow - '71 Ranchero

George49Ford

George49Ford

Senior Member
Stock 302 '71 Ranchero. The coolant recovery container fills quickly but will not return to the radiator. I've pulled and cleaned the container and made sure the hoses were clear. Radiator cap seems to be keeping pressure ok. Any input or suggestions appreciated.

Thank You

George Milliorn
Carson City, NV
 
When it cools, how far down from the filler neck is the water level? My thinking is that perhaps the level is such that the over flow won't return because the radiator was over full and is now at the correct level. If so, just empty the over flow bottle and let 'er go.

I guess I'm saying a little more info would be helpful.
 
I've been in auto wreck repair biz for over 30 years and have serviced a lot of radiators. Once you have comfirmed that your recovery hose is intact, not even a pin hole then check the cap. There should be a small, like one inch umbrella,or flutter valve which opens as your system cool the water contracts and pulls a vacuum, That valve opens and draws coolent from the recovery jug. That is why newer recovery jugs are marked with different hot and cold levels. The cap is wrong or there is a hole in the system, that's all it can be,,,,RooDog
 
For Motorhead6 - When cool the overflow container is full to the top while the radiator is way down. Coolant just keeps going into the overflow and overflows the overflow (I know - redundant) onto the ground. Eventually, I haven't to fill the radiator again.

For RooDog - I'll get get a try a new radiator cap this weekend.

Thanks to both of you gentlemen for your responses.

George M.
 
Ford did not install an overflow bottle in these cars in 71, they did sell an add on kit. So maybe you are trying to use the original design rad cap. If so, it won't work with a closed system/coolant recovery system. Buy one for something built after 73.
 
Craig - I never thought of that but sounds right. Something is not letting the coolant back into the radiator. Thank You, George M.
 
You could have the wrong cap as stated by Craig above, but that would not explain the low level in the radiator. Either you have a leak or a blockage in the flow. Assuming that the engine does not overheat(you did not note that it overheats or shows a leakage) then I would suspect the lower radiator hose is collapsing when the RPMs are elevated. The lower hose should be rigid or have a spring inside it to keep it from collapsing. If not, (these springs are notorious for rusting away in part) the water pump drawing water from the radiator can cause the collapse and then the pressure from water returning to the radiator can override the pressure cap and dump water out the over flow tube. This is a common condition in these early cars. Just squeaze the lower hose when the engine os cold and off. If it can be squeazed, time to replace it.

The other thing it could be is a defective cap as Roo Dog indicates. You can have the cap pressure tested at your friendly radiator shop, usually for free.

Good luck.
 
Motorhead6 - thanks for input. Engine runs very cool with proper amount of coolant. Radiator was installed new about two years ago, not sure if hoses were new at time but I'll check them.

Thank You

George M
 
You must log in or register to reply here.
Back
Top