Date: Tue, 10 May 2016 17:56:53 -0500
Reply-To: John Rodgers <jrodgers113@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <jrodgers113@GMAIL.COM>
Subject: Re: Filling the coolant reservoir...
In-Reply-To: <CA+az7_55jVHbNbKgF5cH78-ugh5X21VzkjwL70cir7K8nZk0eQ@mail.gmail.com>
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Anyone know the actual range of coolant system pressure our vanagons run
at. The coolant absolutely expands and contracts, as the engine heats and
cools, thus the need for the overflow tank. The overflow tank is marked
maximum and minimum when hot or cold, and the overflow tank is vented on
the top backside with three little holes to prevent it from blowing out of
something goes wrong in the system. But it would be interesting to know
what the actual system pressure range is, especially since sea level
atmospheric pressure is 14.7 psi. That weight of air is enough to push the
coolant back in to the system as the coolant cools and shrinks. So what is
actual system pressure at both ends of the spectrum - hot and cold?
John
On May 10, 2016 17:30, "Scott" <SCOTTDANIEL@turbovans.com> wrote:
perhaps have the guy google 'coolant recovery pressure cap for
automotive cooling systems,
then maybe he'll believe coolant expands, such a cap accomodates
expansion by putting the 'extra' in overflow tank , then sucks it back
during cool-down.
cars have used this basic system in one form or another since the 70's ,
even a little earlier.
( rather oddly, my 1985 Mercedes car still uses the old fashioned system
..the air space at the top of the rad is the expasnion zone for
coolant..no overflow / recovery tank. )
re last comment below ..
all cars have some form of a pressure relief cap.
Haven't heard of a totally closed one yet,
though modern car cooling system pressures can be quite high.
here's a whole google search page the guy could read ...help him a lot I
imagine.
in one of those they mention 24psi for a more modern car.
Our vans run in the 13 or 14psi range max I believe.
I have not found the blue caps to be extra reliable. I always carry a
spare.
for example...
saw one Subaru engine conversion with a head gasket issue ..
after problems with the first cap and pressure tank,
they put on a new blue cap and pressure bottle.
pressure got so high...and the new blue cap did not release pressure,
that the pressure bottle puffed out like a football.
I still have it, it's only slightly warped where the level sensor screws
in ...
so new I hate to just throw it in landfill.
scott
On 04/26/2016 08:20 AM, Dan N wrote:
> Neil,
>
> he said that he gives room for the coolant to expand... I told him when the
> coolant expands the blue cap will open and the coolant goes to the
> expansion tank behind the license plate...
>
> he didn't buy it...
>
> I am sure he's thinking as modern car with the radiator and a filling tank
> with no pressure cap and no expansion tank..
>
> haha...
>
> :-)
>
>
