Replace the cooling fluid in the engine

  • Thread starter Andre K. 1991 Hunter 30
  • Start date
Status
Not open for further replies.
A

Andre K. 1991 Hunter 30

Does any one have a practical and mess - less way of replacing the colant in the engine/heat exchanger/hot water tank? if you just open the valve at the side of the engine, it will not drain all of the colant. I am also affraid to create and trap an air bubble in the water heater, which will make the heater ineffective or will compromise the cooling of the engine. Any ideas will be appreciated Thanks
 
D

Don

what engine?

Andre The procedure depends on how the engine is drained so can't be too specific without that info. Generally, the process isn't difficult and should be done periodically to ensure the coolant system functions properly. You may also want to consider some of the silicate-free products which are longer life and less prone to clogging the heat exchanger. There is a good desc of the process on the Yanmarhelp.com site which is applicable to most engines. Don
 
S

Steve O.

just did this

Here's what I did: Open the coolant taps on the starboard side(there are 2 on the 2GM20) there should be little plastic tubes attached for draining into a jug. Disconnect one of the heat exchanger hoses (send or return) at the engine. Then disconnect the oppsoite hose at the HW heater. Connect a dinghy air pump to it and blow it out into a jug. Flush with fresh water by filling and running the engine for a while, maybe 1/2 hour. Keep flushing 'til the water runs clear--could take several flushings. Refill with anti-freeze 50/50 mix (mine took about 1 gallon) and run for another 1/2 hour to make sure there are no air loocks. I used a funnel stuck into the the heat exchanger hose to fill the heat exchanger to avoid air lock.
 
Dec 3, 2003
2,101
Hunter Legend 37 Portsmouth, RI
Same process

I drained the heat exchanger only and let it drain into the engine pan. Then I used my water vac to suck up the old antifreeze. I try to do this annually. It keeps the whole engine cooling system fresh, it doesn't take long to do, and there's little mess.
 
A

Andre K. 1991 Hunter 30

Thank you

Thank you for the response. The engine is the standard for this vessel - 2GM20F. Paul Akers - if you just drain the heat exchanger, is this sufficient?
 
Status
Not open for further replies.