Is there such a thing where 'some' water could leak out, but leave some in, as the RR runs ok. Doesn't overheat, gauge stays at 12 o clock.... I top up reservoir when cold It leaks out from behind the engine, then stops leaking and still runs at running temp.
Range rover v8 3.6 coolant leak
- Thread starter Bigjim80
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brianp38dse
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When you take the cap of and refill you let air in coolant will run out till the cap goes on and keep leak in till it has let up a vacuum in the system then engine gets hot expands and seals leak.
Datatek
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There is never a vacuum in the cooling system, it runs under pressure when hot. The leak may seal due to expansion of metal parts.
brianp38dse
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What I was saying is having just topped up and put cap back there will be no pressure in system and with leak opened due to contraction coolant will leak out till it creates a parcial vacuum unless it sucks air in elsewhere, I work on heating systems cutting into pipe work using this method create a vacuum no need to drain system to work on a pipe.
Datatek
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The only time there is less than atmospheric pressure is as the engine cools. When hot there is 14psi of positive pressure.
brianp38dse
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I was trying to explain the op`s bit ( I top up reservoir when cold It leaks out from behind the engine, then stops leaking and still runs at running temp.) that is how it may leak when just topped up and cold then stop when still cold, the coolant dripping out will create a negative pressure so will stop, unless you open cap again to equal atmospheric pressure then in will drip again.
Datatek
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Removing the cap on a hot engine apart from being dangerous, lowers the pressure to atmospheric but does not create a vacuum.
brianp38dse
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We are talking about when everything is cold not hot.
