Changing Coolants

[Profzarkov]

Hi

Having successfully carried out my own engine service on my Isuzu 42, I was pondering changing the coolant but was unsure how to go about this. It has a skin tank and the hoses are much lower than the engine. I've had the boat for nearly four years and it is eight years old. Does it need changing? I've tested the coolant and it's good down to -17. I've also got an Alde 3010 gas CH system, this is also good down to -25 degrees C. I imagine there must be drain plugs somewhere .

I'm also no sure what coolant to use, the current colour is pink.

Steve

[pearley]

We had ours changed last winter after 8 years. We used Ford Super Premium antifreeze as it has a 10 year life. We biught from Vospers, the Ford dealers in Plymouth via Amazon and was no dearer than getting blue/pink from a motor factors.

 

Look me ages to fully bleed the air out though but our skin tanks with flat in the bottom plate.

[Chewbacka]

Anti-freeze or more correctly these days 'coolant' has two purposes.

Firstly to prevent freezing damage in UK winters, and this can be checked with a little tester - as you did.

Secondly it contains additives to prevent corrosion and they do get 'used up ' over a period of time, the rate of use depends upon the metals present and if there is any chloride (salt) present etc.

 

The blue stuff normally is specified as a having a life of 2 years.

No idea as to the life the pink coolant you have.

Some of the newer coolants last for 10 years, and some, but not all, can not be used if copper is present in your system.

 

So as you don't know how old it is, or what spec it is, it may be worth asking the boat builder what they used, or just change it, though I would wait till the spring when it is warmer.

[Profzarkov]

Thanks guys

Yes, I think I'll wait until it's a tad warmer.

There seems to be no sign of any rust.

The Alde has very limited info on what to use, just suitable for aluminium.

[Bloomsberry]

Thanks guys

Yes, I think I'll wait until it's a tad warmer.

There seems to be no sign of any rust.

The Alde has very limited info on what to use, just suitable for aluminium.

I've never done it myself but a simple test to see how corrosion resistant the antifreeze is is to take a small sample and place a steel object in it ie. nail.

 

If after a day or so there is no corrosion then the antifreeze's corrosion resistance is probably ok.

[Joe the plumber]

I believe it's Organic Additive Technology (OAT) antifreeze that isn't supposed to be suitable for soldered copper systems.

 

One other point worth thinking about is how on earth you're supposed to (legally) dispose of your old antifreeze. Council

tips won't take it and you can't just pour it away. I don't know the answer to that one either.

[Guest]

I believe it's Organic Additive Technology (OAT) antifreeze that isn't supposed to be suitable for soldered copper systems.

 

One other point worth thinking about is how on earth you're supposed to (legally) dispose of your old antifreeze. Council

tips won't take it and you can't just pour it away. I don't know the answer to that one either.

They let me put it in the oil recycling tank at the local tip last time I did a coolant change. Doubt if it will be there next time owing to local government cuts (talk of them all being closed down in our area.)

[Joe the plumber]

I asked about that and our local ones wouldn't let me. Perhaps it depends upon where you are.

[Sea Dog]

 

One other point worth thinking about is how on earth you're supposed to (legally) dispose of your old antifreeze. Council

tips won't take it and you can't just pour it away. I don't know the answer to that one either.

Is this a very new thing? I've certainly disposed of engine coolant at my home council tip in the last 3 years and at the one near my mooring earlier this year. It would be quite a strange move as it would surely consign the vast majority of privately arising waste coolant to the public drainage system.

[WhiteSuit]

I paid our marina to dispose of our old antifreeze, didn't try the local tip to see if they would take it as it was convenient to do it at the marina. They charge because they are charged for disposal. At the moment oil and filters are free at the marina.

[Guest]

I asked about that and our local ones wouldn't let me. Perhaps it depends upon where you are.

Probably. Even the ones in our area which are under the same authority seem to have different rules on different sites! The one I normally use said I could just skip the container including used antifreeze in the non-recyclable skip, but I wanted the container back for next time.

[Jak]

Stupid question of the evening? I've bought "blue" from Halfords which they recon is the right stuff for the BMC 1500. But can I just top up with it or should I worry what the POs have poured in?

[Sea Dog]

Stupid question of the evening? I've bought "blue" from Halfords which they recon is the right stuff for the BMC 1500. But can I just top up with it or should I worry what the POs have poured in?

If you don't know what's in there, you need to drain, flush and refill so that you do. If you do that, you may wish to change to the 5 year life stuff, making sure you choose one compatible with your engine. An alternative to buy you time might be to use 'Prestone' which claims to be compatible with most types of antifreeze. In the long run though, it needs doing right. For me that's 5 year antifreeze mixed with deionized water.

[Chewbacka]

Stupid question of the evening? I've bought "blue" from Halfords which they recon is the right stuff for the BMC 1500. But can I just top up with it or should I worry what the POs have poured in?

Different technology coolants can when mixed precipitate out the silicates (make a fine dust). This is a especially a problem in vehicles with fine bore radiators and transmission fluid coolers. Also the silicates are part of the corrosion inhibiting chemicals and if no longer in solution corrosion protection will be reduced.

 

Best you flush and refill unless you are certain that the stuff already in there is compatible. Just colour is not a safe way to tell.