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I need radiator/cooling system advice.



I have a '79 VB 6 cylinder automatic commodore.
I've never owned a car before and I'm mechanically challenged....BIG time.
I've just spent a hour trying to find an answer to my questions on the web, but I've had no luck so far.
In the "owners" manual it says to check the coolant level in the recovery bottle, as well as in the radiator. In the "workshop" manual it doesn't mention checking a recovery bottle, but instead mentions checking an expansion tank.
Is a recovery bottle and an expansion tank the same thing? How do I identify them and their location?
I thought all I needed to do was to check the coolant level in the radiator, by simply taking off the radiator cap, and topping it up with water if necessary. But it seems I also need to check the recovery bottle/expansion tank as well.
As you can see I'm a mechanical dummy in need of help.

Thanks for any advice.


Mar 30, 2004
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Expansion tank = recovery bottle.
Fill the coolant level in the radiator then top the expansion tank up to the half way mark (there is a water level mark on the side of the bottle).
As the engine warms up, the water expands and is pushed out of the radiator cap and into the expansion tank. As it cools it is sucked back into the radiator again maintaining it at the full level. The old cars never had recovery tanks and as a result you could fill the radiator to the top, go for a drive and after cooling, the water would be about 30 mm below full as it had dumped it out the overflow onto the road. As soon as you can, put some coolant in the radiator, don't just have water only, as without coolant your radiator and heater core will corrode away much quicker.
Heater core is located in the dashboard behind the glove box it is a little radiator that hot water is piped through, air can be directed from the fan through it to heat the cabin. Depending on the model it can take best part of a day to replace a rotten heater core, terrible way to spend a weekend.


Thanks for the reply.

Ok, I've just had look under the bonnet and think I've discovered where the expansion tank is.

There seems to be 2 tubes connected to it, one leading to the radiator. These 2 tubes are connected to a lid on the top of the expansion tank.

By the looks of it I will need to dismantle the tube connections to the lid in order to get the lid off. Is this correct? I can't screw it off because of the tube connections; or do I just use force to pull it up and off? I don't want to damage it.

I can see no markers on the side of the expansion tank that indicate levels, but halfway up I see the letter F. The tank does not seem to be very transparent so it's near impossible to look at it from the outside to see the level of the fluid inside.

The green coolant level in the radiator reaches up to near the radiator cap.

Behind all this is another plastic container with a lid on top full of water..... I presume this is the water reservoir for the windshield wipers, and has nothing to do with the expansion tank.


RIP King of the Mountain
Mar 2, 2006
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southside adelaide
Members Ride
V8 VH SL/E 308
That is correct, one bottle is your expansion tank/overflow bottle, the other is the windscreen washer bottle...
As for taking the lid off your overflow bottle, simply pull the lid off with the hoses still connected...
fill it to the F mark if the engine has been running and is still warm, if stone cold, fill it about half way up, because it will rise as coolant/water heats up... overfilling isn't too much to worry about, thats why there is another hose coming from the lid of the overflow bottle, it'll drain out into the ground...
Everyone starts without knowledge of cars and you'll only learn by research, self-teaching or just asking questions...