Coolant Overflow Tank

[Willysnut1959]

With the radiator cap off and the engine hot, the coolant surges out of the radiator when I shut the engine off. I lose about a gallon of coolant when this happens.

Is this a result of the radiator cap being left off or do I have other issues?

Neither of my 2 -'66 Toronados have coolant overflow tanks. Was this an option or did they never have them?

If they had them, can someone post a photo of what they looked like and where they were located?

Marty, St. Louis

[Otto Skorzeny]

I've never seen a factory one. I installed one from a Nissan on my car that I picked up at the junkyard. I mounted it next to the radiator on the driver's side.

If you remove the cap with the engine off, it's always going to overflow a lot of coolant since it expands when hot. Why are you taking the cap off when its hot?

[Willysnut1959]

Otto,
To answer your question: I replaced the heater core. The old one was full of sediment so I wanted to flush the engine out of the heater hoses before connecting them to the new heater core. I had the cap off so that I could add water to the radiator while the water discharged out of the open heater hoses. I then drained the radiator, connected heater hoses to the heater core, added antifreeze and wanted to watch the coolant inside of the radiator to make sure it was circulating, to relieve air pockets, and to refill. When I shutoff engine to get more antifreeze it puked out about 1 gallon of coolant. I was not sure this was a result of air pockets in the system on the cap being off. Before shutting off the engine the coolant level was 4 to 6" down from the top of the radiator. I did not expect it to rise as quick as it did.

Marty, St. Louis

[Otto Skorzeny]

I see. That sounds like air pockets rising up and forcing the coolant out like you said. That has happened to me on other cars after completely draining the system. I bet it took a while for the big air pocket from the heater core to work its way to the radiator.

Most recently in my Cadillac when I had the radiator repaired I filled it to the base of the filler neck and started the car. A little while after it ran it barfed out a half gallon or so. I should have filled it partway, let it run, add a little more, etc.

[Otto Skorzeny]

Here's your coolant overflow tank:

viewtopic.php?f=5&p=9651#p9651

[Willysnut1959]

Otto,
Thanks for your reply. I viewed Garland's forum post, but missed the aftermarket coolant tank in his photos. After receiving your personal email, I called Garland and he gave me the Dorman part # 54002 and a suggestion on how to mount it in the car.

[Otto Skorzeny]

Cool. It looks really nice. I think I'm going to ditch my junkyard Nissan tank and go with the Garland style one!