Changing enginee coolant

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How often do you change your freshwater engine coolant (with 50% antifreeze mix)? Every year? How do you dispose of the old coolant? Not safe to pump overboard so do you pump out and dispose ashore?
 
You can, from Halfords, buy an antifreeze tester. Which resembles a large pipette tube. This will tell you the capability of the antifreeze in the system. Otherwise, if it starts to change colour, then it'stime for a flush & coolant change.
 
Last changed my Volvo Penta MD2030 at 5 years. One of the messiest jobs to do. Not a hope in hell of collecting the deluge, once it comes. Simply mop-up the bilge with old towels into a bucket. Then, dispose of ashore.

Not sure if there's an elloquent way to do it. I'll watch with interest.
 
Just like your car engine the interval between changes depends on the type of antifreeze.

The traditional type with a silicate based inhibitor should be changed every 2 years.

If you engine is relatively modern it might use the modern long life type with organic acid technology ( OAT) which need only be changed every 5 years .

OAT is the type used in most cars since 1996 but probably only more recently in marine engines

The usual ethylene glycol antifreeze should be safely disposed of ashore as it is toxic to both mammals and aquatic life.
Propylene glycol is, however, relatively safe but not commonly used yet in the UK
 
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Yanmar say to replace after 500 hours or 2 years on my 4JH4AE and I was going to follow the schedule. I checked first with a Yanmar dealer (SWMBO's Godson) and he confirmed that it already had long-life coolant so 5 years was a more sensible interval.

I've seen other replacement intervals that also look silly (2 years for all fuel and water hoses). So I expect that Yanmar must quote very short intervals for everything.

I haven't checked but thought there was a drain point in the block so had hoped to collect the spent coolant when I finally change it. Can't see much harm in using it up as final flush through raw water side, shower pumps etc. for winter storage.
 
i was hoping this year to put the tube from my SEAGO oil extractor over the drain nipple and simply suck out the old antifreeze. unfortunately as other posts detail, the elbow was bunged up so i had to poke a wire down and the antifreeze ran into the engine compartment as normal. however, the SEAGO pump sucked it all up and then decanting it into an old plastic soft drinks bottle was the easy way to dispose of it.
 
Burnham Bob said:
i was hoping this year to put the tube from my SEAGO oil extractor over the drain nipple and simply suck out the old antifreeze. unfortunately as other posts detail, the elbow was bunged up so i had to poke a wire down and the antifreeze ran into the engine compartment as normal. however, the SEAGO pump sucked it all up and then decanting it into an old plastic soft drinks bottle was the easy way to dispose of it.
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It could be argued that putting a toxic, but pleasant tasting, liquid into a soft drinks bottle was a foolish and dangerous thing to do.

:eek:
 
I would of thought if poured into a full bath of cold water
then emptyd and flushed constantly with lots more full baths of water to follow
by the time it reaches the sewage treatment place it will of been so diluted also by everbody elses discharge so as not to be a any risk to anything alive ...but i expect the abuse will maybe start here.....:)
 
Robih said:
How often do you change your freshwater engine coolant (with 50% antifreeze mix)? Every year? How do you dispose of the old coolant? Not safe to pump overboard so do you pump out and dispose ashore?
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Every year? Totally unnecessary. Maybe if I kept a boat long enough I would do it every ten years or so.

Its a bit like the changing brake fluid in a car bit - never needed in the old days but now with all the modern materials and technology they try to tell you to do it every couple of years.
 
Bosun Higgs said:
Its a bit like the changing brake fluid in a car bit - never needed in the old days but now with all the modern materials and technology they try to tell you to do it every couple of years.
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Interesting point BH but my recollection is that 40 years I also would never change brake fluid. However, I did have to change slave cylinder seals, pistons or complete units fairly regularly.

About 20 years ago I read that cylinder deterioration was cause by water being absorbed into the fluid so I started to change the fluid on all my cars and bikes every 3 or 4 years. I have not replaced a single seal, piston or cylinder in the last 20 years. :)

Richard
 
davidjackson said:
Last changed my Volvo Penta MD2030 at 5 years. One of the messiest jobs to do. Not a hope in hell of collecting the deluge, once it comes. Simply mop-up the bilge with old towels into a bucket. Then, dispose of ashore.

Not sure if there's an elloquent way to do it. I'll watch with interest.
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On my 2040 the coolant drain has a small tap/valve on the engine block. On the outlet-side it has a small nozzle about 5-6mm in diameter. I simply connected my Pela oil vacuum pump onto this with a 2" length of rubber hose that joins the Pela hose onto the valve. Sucks out the coolant in no time at all! Maybe not all Pentas come with this valve fitted?

I found it took me about 4 or 5 complete flushes through to get all the murky coolant out and I now have a full 25 litre container sitting in my driveway and was wondering what to do with it. I'm slightly surprised the marina doesn't have a disposal point to minimise the amount that probably ends up down surface drains.
 
davidjackson said:
Last changed my Volvo Penta MD2030 at 5 years. One of the messiest jobs to do. Not a hope in hell of collecting the deluge, once it comes. Simply mop-up the bilge with old towels into a bucket. Then, dispose of ashore.

Not sure if there's an elloquent way to do it. I'll watch with interest.
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Same boat, same year, same engine, same mess!
I changed mine last time May 2010 and was thinking to do it again this year. It's that mess that keeps it at the bottom of the to do list. I will probably empty 1lt from the exchange heater side into a large plastic bottle of water (cut the base and keep the cap closed) and see if the...bottle technique can work with the rest coming out of that stupid square plug by controlling the flow.
 
I've got a Volvo DI 20 and if I drained off the engine coolant through the drain plug in the engine block it would make a real mess. But as I have to winterise the raw water side of the system each year and begruge throwing away almost brand new antifreeze when I restart the engine in the spring I use the following system.

1. Use a Jabsco hand pump to suck out the coolant in the header tank.
2. Disconect the header tank hose from the block and stick a fine tube from the pump into the block and suck out as much of the coolant as I can.
3. Reconnect the header tank and top up with fresh antifreeze mix.
4. Stick raw water intake pipe into the bucket where I have stored the old engine coolant mix and start the engine until that has all been sucked into the raw water side of the system.

Doing it this way does not flush out the engine block but it does ensure that a significant proportion of the coolant is exchanged each year with no mess.

Sooner or later I will have to drain it properly but doing it this way puts off the evil day.
 
RichardS said:
Interesting point BH but my recollection is that 40 years I also would never change brake fluid. However, I did have to change slave cylinder seals, pistons or complete units fairly regularly.

About 20 years ago I read that cylinder deterioration was cause by water being absorbed into the fluid so I started to change the fluid on all my cars and bikes every 3 or 4 years. I have not replaced a single seal, piston or cylinder in the last 20 years. :)

Richard
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Try using DoT5 fluid Richard. It's silicone based and doesnt absorb water. The advice is that it never needs replacing though BMW initially recommended every 2 years on my bike.

Having said that I have only once ever had to replace a slave cylinder even on the old glycol based fluids that did absorb water.

I'm not usually that cynical but as a retired businessman I know what I would do if selling these sorts of fluids. I would recommend changing them as frequently as I thought I could get away with. After all, I would likely be supplying the car maker / bike builder at not much more than cost ( that was my experience of them :( ) so all my return would have to be be made from the after market.

Same sort of thing with spark plugs.
 
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