Radiator and overflow bottle

[Jannelu]

Hello everyone.
I have a 76 Continental Town car (460) and I have noticed that the radiator coolant level drop about 3-4 inches below the radiator neck after i top it up, it however does not seems to get any lower than that..
The car drives beautiful with no overheating issues at all.
I noticed that I hade a small leak from the drain plug but after I tightened it, i did not notice any more coolant on my driveway so I think that the leakage is solved.
I hoped that it was the solution but after i topped it up today, the level dropped to the same level again.
The overflow bottle has no lid on it (very strange) and always stays empty.
Should i fill the overflow bottle up (how?) or do anyone have some ideas?

[action]

When the coolant is heated up it expands.
When it expands the pressure in the closed system increases.
IF the pressure in the cooling system exceed the pressure the cap can contain, coolant will come out past the cap until the pressure is reduced below what the cap can contain.

At this point there are two things needed to be checked because there are some assumptions in the above
1) The cap is still holding the rated pressure it was designed to do
2) More important, the cooling system is holding pressure 5 to 10 PSI greater than the cap.

Assuming the above is yes
The coolant is leaving past the cap during the operation of the engine
The coolant is either going into the overflow container. OR leaving via a leak in the hose or connections at either end of the hose
Or the container has a leak.

Generally with a container it is not necessary to remove the cap to check coolant level. Engine coolant should be filled into the over flow container such that the coolant is a few inches higher than the bottom of the hose. By keeping some fluid in the overflow you can also determine there is NO leak in the hose or connections at either end of the hose.

As the coolant expands out of the radiator and into the over flow the container keeps that fluid. As the fluid cools inside the cooling system coolant in the overflow is sucked back into the cooling system.

If there is NO coolant in the overflow, the radiator cap is allowing air back into the cooling system when cooled down.

Action

[Jannelu]

Thanks Action, you are apparently the knowledge of Lincolns:))
I checked the things you mentioned and, voila, it was a small crack in the hose, close to the radiator, hardly noticeable.
I cut the hose about an inch and filled up the overflow container and it seems to be ok now, the coolant seems to stay in the radiator.
The next task will be to check the excessive fuel consumption, there is no vacuumhose from the distributor to the carburater so I hope thats the culprit, but we well se about that.
Jannelu

[TonyC]

Could at least be a contributor if not the culprit. There's supposed to be a vacuum connection from the carburetor to the distributor, to advance the spark as the engine speeds up, thus contribute to best fuel economy. It's best to start with the simpler stuff, rule them out, before going hard-core.

---Tony