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The mkiv Supra Owners Club

Expansion tank empty, rad cap is new


hadyn

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This is very weird. The level has still not changed, one week and 300 miles on. The level in the rad is just under the neck and in th e main body of the rad. The level in the expansion tank remains at just below the low level.

As stated previously in this thread, I filled the expansion tank when cold last week to the full mark and the system has obviously absorbed/leaked the amount that I put in a week ago.

The weird thing is that the level will never fall below the point it is in the rad.

Do i need to top the expansion tank up whilst the engine is warm or something?

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I think it's been explained as ok hasn't it?

 

sounds like basically when cold the level is at it's lowest and will be near the min mark. Only reaching the max mark when the engine is full hot and the coolant has expanded.

 

filling the expansion right up when cold means the excess just comes out (onto road usually via an overflow pipe?) as the engine heats up and the coolant expands

 

so I think it's all ok, sounds like it's working like mine does

 

just keep an eye on it for a while, never hurts to be safe

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I dont think youre ment to fill the expansion tank mate just the rad.As the name suggests its for when the coolant expands with the heat it will flow into the expansion tank instead of bubbling out the rad cap then when the engine cools it flows back to the rad.Might be wrong but id say there is nothing wrong with youre cooling system.

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Fill the rad to the neck.

 

Then, when hot, fill the expansion tank to the full mark.

 

When the coolant system needs more coolant it takes it from the tank.

 

when the coolant system doesent need the fluid it puts it back in the tank....

 

The level on the rad will never go above the neck, because there is the hose there what connects it to the overflow tank.

 

If the system reaches the set presure of the stock rad cap 1.1bar is it? it will let the coolant into the overflow bottle and viceversa

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Fill the rad to the neck.

 

Then, when hot, fill the expansion tank to the full mark.

 

When the coolant system needs more coolant it takes it from the tank.

 

when the coolant system doesent need the fluid it puts it back in the tank....

 

The level on the rad will never go above the neck, because there is the hose there what connects it to the overflow tank.

 

If the system reaches the set presure of the stock rad cap 1.1bar is it? it will let the coolant into the overflow bottle and viceversa

 

Nice one mate. Was wondering about the accurate reserve limits of the system. Now I know what to do. Thanks. :)

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Thing is though, Ive had two Supras and both have normally settled to the top of the rad neck when cold. Im querying if anything is wrong as my current Supe is the only one where the level is now settling below the neck.

It used to settle to the neck....

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  • 3 weeks later...

Just to update this thread. Yesterday I filled the rad with a tiny bit of 4life so that it was full to the neck, not to the point where it now settles under the neck.

When cooled the rad still returns to this level below the neck. If I add extra coolant it just disappears, but the level will not fall below this mark.

What is going on? Is there a leak by the neck area of the rad or something???

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