1610D Loosing Coolant

wscott · Apr 11, 2004

My yanmar is loosing coolant through the overflow bottle. The coolant bottle stays full because the coolant does not drain back into the radiator after the tractor has cool off.
Could this be the radiator cap or problem the radiator or engine.

YanmarFever · Apr 11, 2004

I would replace the radiator cap first & see what happens,
its a cheap fix compared to a dismantle of your cooling system.
Ern.

gbirky · Apr 12, 2004

Someone may have replaced the cap with an incorrect one. You need one specifically for a recovery system - most of the Yanmars are 13psi.

BigAl · Apr 12, 2004

Radiator cap for sure ! Look at the old one and see if the rubber seal is torn or split . I bet it is . Just get a new cap "13psi" that is for a "recovery type system" .
Big Al

BigAl · Apr 12, 2004

I forgot ! Make sure your recovery hose does not have a hole in it as this will also stop it from working .
Big Al

wscott · Apr 12, 2004

Thanks,

I will be getting a new radiator cap order tomorrow. The rubber on the old cap is in good condition.

BigAl · Apr 12, 2004

If it is a recovery type cap , it will have two rubber seals on it . One outer and one inter .
BigAl

jbitting · Apr 12, 2004

This may sound silly, and you've probably already looked there, but... make sure the cap for your recovery bottle also has the hose INSIDE of it (mine didn't when I bought it)... so it would flow into the bottle, but upon cooling would suck air back into the radiator... /forums/images/graemlins/blush.gif
..and make sure it too, is not cracked or sucking air toward the top.

of course, if it fills from the bottom... well...
just forget I mentioned it. /forums/images/graemlins/wink.gif

kayssupply · Apr 13, 2004

I had one that someone had put a hose on the inside that was too big. They had wrapped a wire around it to hold it on, but it was loose enough to suck air, not water.

wscott · Apr 23, 2004

I got a new radiator cap installed, but this did not solve my problem. My dealer thinks it my be a cracked head. The coolant will complete fill my overflow bottle when i have ran the tractor for about 3 to for hours and overflow the bottle.
There are small bubbles in the overflow bottle (foamy at the top). Would a cracked head or blown head gasket cause this problem or a stopped up radiator. When i remove the radiator cap after the tractor has cooled down, there is still pressure built up in the radiator.