Changing antifreeze

[marchem]

One project I still haven’t gotten to after three + years is changing the antifreeze. I’ve read about it on this forum, but I’m not clear on the best way to drain as much as possible, without most of it ending up in the bilge.

Any tips for doing this as neatly as possible?

Thanks!

 

[Michael Davis]

Mine has a drain plug at the back of the heat exchanger. Used a empty yogurt container to catch it all. Doesn't drain the block but gets most.

 

[Gunni]

Connect vinyl drain hose to the AF petcocks and direct the flow into a container. You can find the right hose size at a hardware store.

 

[MikeHoncho]

Coolant cavitation on the cylinder walls is a issue with diesel truck engines. I haven't found any discussion on it in these small guys but when I change mine out I'm going to use the applicable coolant with SCAs (supplemental coolant additives) . They make test strips to check the levels also.

 

[marchem]

Connect vinyl drain hose to the AF petcocks and direct the flow into a container. You can find the right hose size at a hardware store.

I wish! No AF petcocks on the engine, M25XPB. There is a drain plug, but not easy access to it.

 

[Michael Davis]

but not easy access to it.

If it were easy it wouldn't be boat approved! @Gunni must have the wrong engine in his boat.

 

[Gunni]

I wish! No AF petcocks on the engine, M25XPB. There is a drain plug, but not easy access to it.

The joys of Yanmar ownership. Add petcocks, this ain’t rock science.

 

[Gunni]

Coolant cavitation on the cylinder walls is a issue with diesel truck engines. I haven't found any discussion on it in these small guys but when I change mine out I'm going to use the applicable coolant with SCAs (supplemental coolant additives) . They make test strips to check the levels also.

Marine diesels run at high-load pretty much all the time which sets up cavitation in the coolant and Yanmar’s in particular have thin-wall cylinders - need protection from cavitation corrosion. You won’t lose the additives, you may well pick up salt from the heat exchanger. So you need to change out contaminated coolant.

 

[MikeHoncho]

Marine diesels run at high-load pretty much all the time which sets up cavitation in the coolant and Yanmar’s in particular have thin-wall cylinders - need protection from cavitation corrosion. You won’t lose the additives, you may well pick up salt from the heat exchanger. So you need to change out contaminated coolant.

My previous research found that the additives degraded over time. This was the reason for the strips but this is applicable to long haul trucks. I would think changing out the coolant every other year or so would be fine.

 

[BigEasy]

You can also disconnect the heater hose from the engine and attach a water hose splice/nipple to attach to the suction side of a jabsco hand pump to suck the fluid from the water heater and associated lines after draining the heat exchanger and reservoir. After flushing with distilled water, drain the system again. After adding new coolant to the heat exchanger and reservoir, you can reverse the setup on the hand pump to refill the heater hoses and heater with coolant...helps to rid the system of trapped air that can cause cavitation and overheating.

 

[Cat 310 #1 in GA]

I found some Youtube videos and followed them. Specific to engine type of course. Easy with my 2GM20F and I used Yanmar brand antifreeze mixture to refill.
bob

 

[marchem]

I found some Youtube videos and followed them. Specific to engine type of course. Easy with my 2GM20F and I used Yanmar bfand antifreeze mixture to refill.
bob

Still hoping for someone with an M25XPB in a Catalina 310 to respond...

 

[JK_Boston_Catalina310]

I've done this 4 or 5 times and have not found a way to not have some mess.

At the dock, I used a radiator flush kit from the auto store. You can put this inline with the hose to the water heater. I then removed the thermostat and flushed water through the system collecting it in buckets for disposal until it was clear. Then I just dumped the buckets out on the ground. Then I used a drill pump to push coolant into the system. I still had some air-bound issues doing it this way I had to deal with.

Next time I just used a drill pump and had buckets to collect the coolant and water to push through the system to flush it with the drill pump. Worked fine but still air-bound issues to deal with.

My current method is to drain the system completely just using drain plugs and removing hoses. There is a drain on the heat exchanger, a drain on the block next to the head bulkhead and then draining the water heater is a pain. Yes this makes a mess and some coolant gets in the bilge, mainly from the water heater. I will use a shop vac to help drain some of it. The coolant from the block goes into the engine bilge and can be pumped out for disposal. I have installed the "MaineSail" system for burping the system and getting out the air and its simple. You can get the best procedure that works for me from the C34 Tech Wiki. Response #14 has the "MaineSail" system.

A good thing to remember is that the C34 essentially has the same engine as us. So a lot of the Tech Wiki stuff is directly applicable to our engines.

Something interesting I found a couple of months ago. The engine was getting a little warm but the coolant level in the tank wasn't changing. I found that the hole that goes from the pressure cap to the coolant tank was blocked. I used some small drill bits turned by hand to clean it out.

Good luck and fair winds,

Jesse

 

[marchem]

I've done this 4 or 5 times and have not found a way to not have some mess.

At the dock, I used a radiator flush kit from the auto store. You can put this inline with the hose to the water heater. I then removed the thermostat and flushed water through the system collecting it in buckets for disposal until it was clear. Then I just dumped the buckets out on the ground. Then I used a drill pump to push coolant into the system. I still had some air-bound issues doing it this way I had to deal with.

Next time I just used a drill pump and had buckets to collect the coolant and water to push through the system to flush it with the drill pump. Worked fine but still air-bound issues to deal with.

My current method is to drain the system completely just using drain plugs and removing hoses. There is a drain on the heat exchanger, a drain on the block next to the head bulkhead and then draining the water heater is a pain. Yes this makes a mess and some coolant gets in the bilge, mainly from the water heater. I will use a shop vac to help drain some of it. The coolant from the block goes into the engine bilge and can be pumped out for disposal. I have installed the "MaineSail" system for burping the system and getting out the air and its simple. You can get the best procedure that works for me from the C34 Tech Wiki. Response #14 has the "MaineSail" system.

A good thing to remember is that the C34 essentially has the same engine as us. So a lot of the Tech Wiki stuff is directly applicable to our engines.

Something interesting I found a couple of months ago. The engine was getting a little warm but the coolant level in the tank wasn't changing. I found that the hole that goes from the pressure cap to the coolant tank was blocked. I used some small drill bits turned by hand to clean it out.

Good luck and fair winds,

Jesse

Thanks. Just what I was looking for, even if it means I’m looking at a mess.... no wonder I’ve been avoiding it!

 

[KZW]

I have a 6-qt manual oil extractor (rather old) left over from my motorboat days. I empty the reservoir on the bulkhead with a couple pumps of the extractor hose. I then put the extractor hose in line with the hose to the water heater, give a few pumps, and let it fill up. The only mess is the fluid that come out of the water heater one before shoving the cain hose inside. That is taken care of by a small plastic cup and a few paper towels.

 

[marchem]

I have a 6-qt manual oil extractor (rather old) left over from my motorboat days. I empty the reservoir on the bulkhead with a couple pumps of the extractor hose. I then put the extractor hose in line with the hose to the water heater, give a few pumps, and let it fill up. The only mess is the fluid that come out of the water heater one before shoving the cain hose inside. That is taken care of by a small plastic cup and a few paper towels.

Interesting. I’ve got two small oil extractors, so I could try that. Of course the antifreeze would get contaminated with oil which might make it harder to dispose of properly.

 

[Clydo]

My previous research found that the additives degraded over time. This was the reason for the strips but this is applicable to long haul trucks. I would think changing out the coolant every other year or so would be fine.

My engine manual says drain and replace coolant every 500 hours?

Clyde Thorington
C310 #24
I LEAN TOO
San Jose, CA

 

[KZW]

Practical Sailor says diesel antifreeze can go five years. My boat is 2005 and has 433 hours on the engine.

 

[RoyS]

I once had a pump impeller fail in its third year (with 200 - 300 hours). Because of that, I now replace both engine impellers every two years. During these impeller replacements, since some of the antifreeze is going to spill out anyway, I drain and replace all of the antifreeze at that time. For me, the impeller replacement drives the antifreeze replacement and not the life expectancy of the antifreeze.

 

[marchem]

I once had a pump impeller fail in its third year (with 200 - 300 hours). Because of that, I now replace both engine impellers every two years. During these impeller replacements, since some of the antifreeze is going to spill out anyway, I drain and replace all of the antifreeze at that time. For me, the impeller replacement drives the antifreeze replacement and not the life expectancy of the antifreeze.

On the M25XPB in most of the C310s the only impeller is in the raw water circuit. The pump for the antifreeze apparently has no maintenance involved. But not a bad idea to change both at the same time.