I hope I can get some help from the diesel DIY people on this forum. I am trying to do more maintenence myself and need to get over some diesel ignorance. 1. First, what the heck is the "fill cap" and the little plastic pressure overflow tank (both located on top) for on my raw-water cooled engine (3GM30). Is this just a vestige from the fresh-water cooled version? 2. What's the purpose of the vented loop that comes off of the raw water intake right at the engine? This thing is leaking salt water on the engine, and I've got a corrosion mess to clean up. I've caught it before any major damage was done, but I've got to understand this and fix it. Maybe it's just a case of new hoses and clamps. Appreciate any help. Paul sv Escape Artist h336
- Status
Part Two Answer
The vented loop is a vacuum break to prevent siphoning. FWIW, I have labored over several of these over time and wound up replacing all of them with Vetus units eventually. I'll leave part one to others who know the boat. I have no idea why you would have a coolant recovery unit on a raw-water cooled engine. It IS raw-water cooled, right, not just raw-water cooling a water/antifreeze coolant through a heat exchanger? Good luck, Rick D.
The vented loop is a vacuum break to prevent siphoning. FWIW, I have labored over several of these over time and wound up replacing all of them with Vetus units eventually. I'll leave part one to others who know the boat. I have no idea why you would have a coolant recovery unit on a raw-water cooled engine. It IS raw-water cooled, right, not just raw-water cooling a water/antifreeze coolant through a heat exchanger? Good luck, Rick D.
Got a manual?
First thing to do would be to get a shop manual from Mack Boring or some other Yanmar dealer. Mine has been a lot of help. Are you sure your engine is raw water cooled? If there is a plastic expansion tank, that indicates it is raw water cooled unless someone converted it, and I doubt that it has been. I have had a vented loop leak on the raw water line also. You might as well change it out and get a Vetus vented loop. They are better than the standard loop and has a drain line so that if the small valve on the top should leak, it will drain down the line to the bilge instead of on the engine. I believe that Hunter is using the Vetus on their new boats now. Good luck.
First thing to do would be to get a shop manual from Mack Boring or some other Yanmar dealer. Mine has been a lot of help. Are you sure your engine is raw water cooled? If there is a plastic expansion tank, that indicates it is raw water cooled unless someone converted it, and I doubt that it has been. I have had a vented loop leak on the raw water line also. You might as well change it out and get a Vetus vented loop. They are better than the standard loop and has a drain line so that if the small valve on the top should leak, it will drain down the line to the bilge instead of on the engine. I believe that Hunter is using the Vetus on their new boats now. Good luck.
PAUL, I COULD BE OFF BASE WITH YOUR BOAT..
but both my H28 and P42 use raw water to cool the closed system engine coolant via a heat exchanger. The expansion tank is used for the closed fresh water/anti freeze coolant mix, which needs to be kept at the proper level. Your engine should have two water pumps; raw and fresh. I would be surprised if yours is different, but then the world is full of surprises. Terry P.S I'm sure someone on this forum will set me straight.
but both my H28 and P42 use raw water to cool the closed system engine coolant via a heat exchanger. The expansion tank is used for the closed fresh water/anti freeze coolant mix, which needs to be kept at the proper level. Your engine should have two water pumps; raw and fresh. I would be surprised if yours is different, but then the world is full of surprises. Terry P.S I'm sure someone on this forum will set me straight.
What vetus unit?
You've all been very helpful, thank you. When you say "Vetus unit" do you mean that you installed a Vetus strainer, and it somehow doesn't require a vented loop, or does Vetus make the little valve thing in the middle of the loop. I visited the Vetus website and all I saw were the strainers. And yes, it is a fresh-water cooled engine with an exchanger. 3GMF30. That's what I get for having the yard decommission my engine every year.
You've all been very helpful, thank you. When you say "Vetus unit" do you mean that you installed a Vetus strainer, and it somehow doesn't require a vented loop, or does Vetus make the little valve thing in the middle of the loop. I visited the Vetus website and all I saw were the strainers. And yes, it is a fresh-water cooled engine with an exchanger. 3GMF30. That's what I get for having the yard decommission my engine every year.
Confusion Reigns?
Paul, let me (as well as others reading this) give you a bit of advice. During the winter and spring, there are usually several basic diesel courses offered by Yanmar dealers, (and others), Mack Boring and other manufactutrers. You should enroll in one of these 1 or 2 day courses. For the price, it is well worth it. The money you save on regular maintenance during the first year will more than pay for the course. They run in the $100 - $200 range. Ask around to people who have taken the course - I'm sure they will agree. In the meantime, this site has many experienced people who can offer helping advice to you. In the future, you will be able to share your experience and advice here, also. In the meantime, plan to take a courseas soon as one is available and definitely buy a Yanmar manual for your engine . Good Luck.
Paul, let me (as well as others reading this) give you a bit of advice. During the winter and spring, there are usually several basic diesel courses offered by Yanmar dealers, (and others), Mack Boring and other manufactutrers. You should enroll in one of these 1 or 2 day courses. For the price, it is well worth it. The money you save on regular maintenance during the first year will more than pay for the course. They run in the $100 - $200 range. Ask around to people who have taken the course - I'm sure they will agree. In the meantime, this site has many experienced people who can offer helping advice to you. In the future, you will be able to share your experience and advice here, also. In the meantime, plan to take a courseas soon as one is available and definitely buy a Yanmar manual for your engine . Good Luck.
why take a class...
...when I've got you guys to help me? I want to stop a drip, not put Kip down at the yard out of a job. He's a great guy! Thanks everyone, especially Rick who made a trip back to the Vetus site to look for me. Paul sv Escape Artist
...when I've got you guys to help me? I want to stop a drip, not put Kip down at the yard out of a job. He's a great guy! Thanks everyone, especially Rick who made a trip back to the Vetus site to look for me. Paul sv Escape Artist
- Status