Antifreeze Leak

[buddybear]

Have had a perplexing leak in the coolant system. Have changed a few hoses which seemed suspect and could have been leaking. What is happening now is I can run the engine for 20 minutes at dock check for leaks and none. Come back in 5-8 hours no leaks. Come back next day small puddle on port front below engine. That is where things run to below the engine. Finally, today I found a drip. It is where the motor mount on the starboard front side attaches to the engine. The antifreeze leaks there then runs to the port front. I was hoping that the antifreeze was leaking higher up in the engine then working its way down to the area where it is dropping off. I looked at the parts breakdown and there are two plugs in that area. My question is when anyone has removed that mount are those plugs in an area that antifreeze is. I am attaching a picture to show where the leak is. Any suggestions would be helpful.

Thanks,
Mark

 

[john2]

Those holes should be "blind" holes, however it is 25 yrs old.... And the bracket is quite low on the engine, my gues if those bolds leak it would be oil coming out. Check the head gasket, waterpomp , thermostat housing and hoses. The bracket looks also a bit cracked.
Just remove the bracket and check everything. place some pieces of paper towel to see where its coming from.

 

[buddybear]

Those holes should be "blind" holes, however it is 25 yrs old.... And the bracket is quite low on the engine, my gues if those bolds leak it would be oil coming out. Check the head gasket, waterpomp , thermostat housing and hoses. The bracket looks also a bit cracked.
Just remove the bracket and check everything. place some pieces of paper towel to see where its coming from.

Thanks for the reply, the bracket connects the motor mount to the engine. If I remove it, do I have to support the engine on that side in another manner or will it be fine on only 3 mounts? I see you have #58 mine is #57, I bought it in 2012 with 683 hrs on the engine I now have 2900 hrs.

 

[jssailem]

It is unclear if the crack in your picture is the source of the leak. It may be. In my opinion, the crack of an engine mounting bracket is not going to repair itself. You do not want to be running your engine on three brackets. Perhaps if you are in an emergency and hoping to get to a safe harbor before a hurricane, but not in a normal use condition.

Looking for an antifreeze leak always starts at the hoses and coolant tank reservoir. The temperature sensor is another usual suspect. Does your tank have an overflow hose and a pressure cap? That is another source of antifreeze in the bilge. It usually occurs if you overfill the tank with more antifreeze solution than designed for the engine.

 

[JoeWhite]

Mark, you have not mentioned the engine type. On my M35B there is an antifreeze drain plug on the port side of the universal engine. Place a small container below the plug and loosen it and see what comes out of the engine block. There are only 2 choices, oil or antifreeze. If antifreeze leaks out, then either tighten it and run engine again, or remove the plug, apply plumber's pipe paste and install and test. An image of the plug might help us.

DrainPlug_FreshWater_DSC03890 | Fresh Water Cooling system | Catalina 36 MKII Album | Sail La Vie Home

mei1970.org

 

[koenigbe]

Question: Did you follow and feel by hand the hoses the whole length? I had a hose completely worn out from vibration somewhere between both ends. Completely out of sight, but you could feel with your fingers. Good luck to you.

 

[dmax]

Also check the radiator cap.

 

[buddybear]

Also check the radiator cap.

Yes, I have checked all of the usual spots and have replaced whatever hoses were worn. The thing about this leak is that I see it the next day after I run the engine, and it will continue to leak for several days after. The drip is from the starboard front bracket where it attaches to the motor mount. I am guessing that it is leaking higher up and over time finally works its way under the engine. I have placed paper towels used the flashlight and only see the drip at the bracket. Very perplexing. I really appreciate all of the advice. The engine is a Universal 25xpb 2001.

 

[john2]

Thanks for the reply, the bracket connects the motor mount to the engine. If I remove it, do I have to support the engine on that side in another manner or will it be fine on only 3 mounts? I see you have #58 mine is #57, I bought it in 2012 with 683 hrs on the engine I now have 2900 hrs.

hello, if you remove the bracket, you have to support the engine with wood blocks .
we are second owner since 2022, engine hours around 2000

 

[buddybear]

Yes, I have checked all of the usual spots and have replaced whatever hoses were worn. The thing about this leak is that I see it the next day after I run the engine, and it will continue to leak for several days after. The drip is from the starboard front bracket where it attaches to the motor mount. I am guessing that it is leaking higher up and over time finally works its way under the engine. I have placed paper towels used the flashlight and only see the drip at the bracket. Very perplexing. I really appreciate all of the advice. The engine is a Universal 25xpb 2001.

Still have not found the source of the leak. Has anyone had a small crack in their engine block which could cause this or is that a very rare chance that this could be the cause. The engine runs fine no overheating, oil is fine no sign of coolant in oil.

 

[Tally Ho]

I was losing AF from my Yanmar 2GM20F, but could only tell because the AF level in the HX would drop. I never could find it under the engine.

I spent a while tightening every hose clamp I could find on the engine…

And she no longer lost AF.

But I am sure you already did this.

Greg

 

[buddybear]

I was losing AF from my Yanmar 2GM20F, but could only tell because the AF level in the HX would drop. I never could find it under the engine.

I spent a while tightening every hose clamp I could find on the engine…

And she no longer lost AF.

But I am sure you already did this.

Greg

Thanks for the reply, I find my leak under the engine but only 24 hours later no noticeable leaks from hoses etc.

 

[buddybear]

Have had a perplexing leak in the coolant system. Have changed a few hoses which seemed suspect and could have been leaking. What is happening now is I can run the engine for 20 minutes at dock check for leaks and none. Come back in 5-8 hours no leaks. Come back next day small puddle on port front below engine. That is where things run to below the engine. Finally, today I found a drip. It is where the motor mount on the starboard front side attaches to the engine. The antifreeze leaks there then runs to the port front. I was hoping that the antifreeze was leaking higher up in the engine then working its way down to the area where it is dropping off. I looked at the parts breakdown and there are two plugs in that area. My question is when anyone has removed that mount are those plugs in an area that antifreeze is. I am attaching a picture to show where the leak is. Any suggestions would be helpful.

Thanks,
Mark

Does anyone have a flow diagram which shows how the coolant flows through the engine? I am placing paper towels around every area I think the coolant could be leaking. Ran the engine late yesterday and will check this afternoon to see if I found anything. Had a friend look at it yesterday and couldn't find anything that looked suspicious. If it would leak while I am running the engine it wouldn't be hard to find it. The The problem is only after a period of time the leak shows up.
Thanks for the Replies.

 

[JoeWhite]

If I had to guess the source of leak from your description, it appears it is due to expansion and contraction of engine due to heating and cooling. I would look for leaky gaskets, such as the thermostat, water pump, and alike.

 

[buddybear]

If I had to guess the source of leak from your description, it appears it is due to expansion and contraction of engine due to heating and cooling. I would look for leaky gaskets, such as the thermostat, water pump, and alike.

Thank You, I will check that.
Mark

 

[buddybear]

Have had a perplexing leak in the coolant system. Have changed a few hoses which seemed suspect and could have been leaking. What is happening now is I can run the engine for 20 minutes at dock check for leaks and none. Come back in 5-8 hours no leaks. Come back next day small puddle on port front below engine. That is where things run to below the engine. Finally, today I found a drip. It is where the motor mount on the starboard front side attaches to the engine. The antifreeze leaks there then runs to the port front. I was hoping that the antifreeze was leaking higher up in the engine then working its way down to the area where it is dropping off. I looked at the parts breakdown and there are two plugs in that area. My question is when anyone has removed that mount are those plugs in an area that antifreeze is. I am attaching a picture to show where the leak is. Any suggestions would be helpful.

Thanks,
Mark

Another question is the injector pump cooled by the freshwater cooling system. I did find that Kubota tractors normally are. I am finding coolant on top of the injector pump. Maybe that is my leak.

 

[john2]

i,m still on for the head gasket or a freeze plug. Our engines are getting to the age that gaskets and seals start to fail....
in time i will do a full rebuild on the engine and transmission. it is leaking here and there a few drops.