Adding Coolant

[River Bank]

Hello

On a 2010 R25 where does one add coolant should the coolant gauge indicates over-heating (low coolant levels)?
There is a fragile looking plastic reservoir located in the cockpit starboard floor locker, but it looks like it would not be able to handle the coolant heat.

Bob

 

[knotflying]

If you have the Yanmar 4BY-150 there should be a cap right on top of the heat exchanger. Similar to a radiator cap. As far as the overheating goes, if your fluid is low you should check for leaks at all hose connections. A typical culprit is the heater at the helm. If your fluid is at level you should check your raw water flow. You could also have some scaling build up in the heat exchanger and a cleaning with Rid Lyme may be in order.
PS: Make sure you use long life antifreeze.

 

[elan]

Good morning Riverbank,
Knotflying gave you some good advice including using extended wear coolant, do NOT use coolant bought at Napa or Wall Mart.
Pay the extra & only use the more expensive extendid life.
Now to answer your question about the small pollypropeline tank located on the starboard side in the engine room, it is a expansion tank that allows the to coolant to expand as your engine heats up during operation.
After you have operated the engine for some time you will notice that the coolant level is higher than it is when the engine is cool.
When the engine is cool the level should not be below the low level line that is marked on the tank.
If it goes below that mark when it is cool, again follow Knotflying's recommendations.
Good luck,
Mike
M/V
Elan
Cutwater 26 with the 180HP Yanmar

 

[STELLA L]

A few month ago I had to change my anti freeze in my Yanmar 4BY-150. I wanted an anti freeze that I could buy off the shelf in case the Yanmar brand was not available. Since anti freeze has become as complicated as oil I called Covich Williams Marine Supply in Seattle for advice. They highly recommended DELO EXTENDED LIFE (750,000 miles, red color) which I did find in a local marine supply store.

 

[knotflying]

A little background here. I originally tried to find the "Approved" antifreeze listed in the Yanmar book and could not find any so I called Havoline, which was one of the approved suppliers. The person I spoke to said the reason I could not find any of the approved brands by number was because they were all Asian numbers. He told me that his opinion was buy any brand as long as it is extended life. The formulation is basically the same. I also recall that Yanmar actually came out with a supplemental list that did among other brands have Prestone listed. I cannot recall the other brands though.

 

[doke01]

If you are in central NJ you can get Yanmar coolant and oil at Monmouth Marine Services and Yanmar coolant at Lockwood Boat Works. Both sell Yanmar parts. I liked the experience at Monmouth Marine better.