Volvo D2-55 Coolant flush and "expiry" of old coolant

[MagicalArmchair]

I have not yet changed the coolant in Mirages D2-55, so that job now approaches and I'd like to do similar to Tino below:

A few questions:

1. Tino flushes with fresh water from the marina without filtering it. I've seen the crud (flecks of rust) that comes from the marina pipes, and also the water is quite hard. Wouldn't it be better using deionised water to flush the system?
2. The boat has all sorts of half filled bottles of concentrated Volvo coolant. I am unsure of its age, and unsure whether it has already been mixed with water. Would you use it? Does it go off? None of it is sealed.
3. Would you drain straight into the bilge? Or what would you catch the old stuff in?
4. The time before last, I noted my expansion tank was empty, so I topped it up! I visited the boat post lockdown today, and its empty again. There appears to be nothing in the bilge. Any thoughts where this is going?

 

[peter gibbs]

Fresh water for flushing has to be fine in preparation for winterising. It's what I do ashore.

Most likely what's in the cans is original strength so good for laying up, suitably diluted; as a precaution just go 50;50.. This for the raw water system.

Replacing coolant in the closed system is advisable every couple of years, either by syphoning out the top of the engine or using the drainage tap. Replace with 50;50 A/F.
In between years , top up with neat a/f if you've already added fresh water during the season.

Excessive precision in this routine is not necessary, I have learned.

Coolant is often cited as disappearing mysteriously. Many of us know about this - loss through the heat exchanger is most likely - not a reason to dismantle or muck about with a functioning system, Only if losses are exceptional - ie topping up lots after every run, is it necessary to investigate further or apply a sealant fluid.

PWG

 

[PaulRainbow]

Tino talks about "some ant-freeze" having anti corrosion additives and they have an annual service interval, whereas the stuff he's using is every two years. That's wrong. The stuff he's uses does have a two year service interval, but it does have anti corrosion additives. The VCS long life antifreeze (yellow) also has anti corrosion additives, but the service interval is 4 years, not one.

1. Tap water is fine, obviously without bits of rust etc.

2. Bin it.

3. Your engine has a drain tap halfway along the left hand side of the block, when viewed from the front. Put a hose on that and drain it into a container.

4. Possibly the heat exchanger, keep a close eye on water levels.

 

[RichardS]

You should be able to tell whether the antifreeze is concentrate or diluted. If it is slightly thick/oily/gloopy it is concentrate. If it's just like coloured water it's dilute.

I would use it and make up the volume with new stuff as required.

Of course, if you do this "winterising" thing through the seawater pump and heat exchanger and out through the elbow, you could use it for that and use the new stuff in the circulation system.

Richard

 

[MagicalArmchair]

Tino talks about "some ant-freeze" having anti corrosion additives and they have an annual service interval, whereas the stuff he's using is every two years. That's wrong. The stuff he's uses does have a two year service interval, but it does have anti corrosion additives. The VCS long life antifreeze (yellow) also has anti corrosion additives, but the service interval is 4 years, not one.

1. Tap water is fine, obviously without bits of rust etc.

2. Bin it.

3. Your engine has a drain tap halfway along the left hand side of the block, when viewed from the front. Put a hose on that and drain it into a container.

4. Possibly the heat exchanger, keep a close eye on water levels.

Thank you.

1. I'll use the filter I've put together for our drinking water to make sure no 'bits' get into the system when I drain it through.

2. I did think that - I know its 'probably' fine, and the PBOer in me wants to save dosh, but I'd prefer to use stuff I know hasn't had anything else dropped into it for the sake for a few quid.

3. Alas there is no tap on these earlier D2-55s, so down the side of the engine it'll run .

4. Anywhere I can see it dripping out? Workshop manual states: How on earth can air get forced into the cooling system? The dreaded exhaust elbow??