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Question about New Coolant Tank Bottle on Closed System

R

rick3452

Regular Contributor
Hi Everyone, A few weeks ago I replaced the over flow "bottle" on my Mercruiser 5.0. I did this mostly because the original bottle was so old 2000 that you really couldn't see the level inside. So I installed it and filled it to the proper "cold" level and ever since the first time out the new clear hose has filled and the level in the bottle never changes it always remains at the cold level. The clear hose remains completely filled.
Thanks for any thoughts and by the way temp runs perfect 160.
Rick
 
rick3452 said:
Hi Everyone, A few weeks ago I replaced the over flow "bottle" on my Mercruiser 5.0. I did this mostly because the original bottle was so old 2000 that you really couldn't see the level inside. So I installed it and filled it to the proper "cold" level and ever since the first time out the new clear hose has filled and the level in the bottle never changes it always remains at the cold level. The clear hose remains completely filled.
Thanks for any thoughts and by the way temp runs perfect 160.
Click to expand...
Rick, think of this as a coolant "recovery" system.
As the coolant heats, it also expands.
As it expands, it wants to leave the H/E and it needs a place to go.
The place to go is the recovery reservoir.

The line between the H/E and the recovery reservoir must be pressure/vacuum tight.

The line connects to the reservoir and the coolant is directed towards the bottom where it is always below coolant level.

As the coolant contracts, it is sent back to the H/E... but only if it pulls from the bottom, and only if the line is pressure/vacuum secure at either end.

The H/E pressure cap must be correct. The correct cap will have two areas of sealing and a one-way valve so to speak.

The fill neck at the H/E where the cap seats, must also be in perfect condition as to seal well.

So.... basically you have several concerns:

  • small breach in the two line connections.
  • wrong style cap for a recovery system.
  • damaged fill neck area where the outer cap seal rests.

.
 
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