Which Anti freeze to suit 1991 Ford Sabre engines

[superheat6k]

During a recent trip I had to replace a failing elbow which meant I had to drain the freshwater side coolant. The fluid that came out was distinctly brown and gunky.

So I now wish to thoroughly flush both engines coolant systems (fresh water side) and then replace the coolant with fresh antifreeze suitably diluted to ~35%.

I am more interested in a long service life than lowest price.

I need a total of ~20 - 25 litres per engine at 35% concentrate. So ~ 15 litres of neat concentrated anti freeze.

Can I use OAT, as most seem to list this as a feature ?

Also best flushing agent for the fresh water side of the engines ?

How long is this stuff best left circulating ?

Best supplier for these products e.g. via Ebay.

Then for the seawater side I hear Rydlyme is hard to obtain presently, so do I simply use HCL Brick cleaner or something more gentle such as Sulphamic acid.

I suspect its a while since the engines have been properly flushed through.

Thanks.

 

[VicS]

Use OAT only if that is what is specified, other wise use a conventional type. Do not mix the two types.

If using OAT after conventional the system should be flushed with oxalic acid solution, alternatively use a universal, type which is compatible with both types

Unless your tap water supply is very low in dissolved solids use distilled water for dilution , or buy it ready diluted.

Do not extend the intervals between coolant changes because of the risk of contamination with salt water.

If you cannot obtain Rydlyme , or even if you can, consider ProFlush Marine Engine Descaler sold by Force4 and the subject of a recent thread on this forum. Pro Flush alternative to Rydlyme
Alternatively use Fernox DS3 descaler, which is sulfamic acid based,
Circulate until analysis shows no further reduction in acid concentration or until reaction seems to have ceased , but not used all the acid. A useful feature of the Proflush is that it contains an indicator which will show if all the acid has been neutralised.

 

[Beneteau381]

During a recent trip I had to replace a failing elbow which meant I had to drain the freshwater side coolant. The fluid that came out was distinctly brown and gunky.

So I now wish to thoroughly flush both engines coolant systems (fresh water side) and then replace the coolant with fresh antifreeze suitably diluted to ~35%.

I am more interested in a long service life than lowest price.

I need a total of ~20 - 25 litres per engine at 35% concentrate. So ~ 15 litres of neat concentrated anti freeze.

Can I use OAT, as most seem to list this as a feature ?

Also best flushing agent for the fresh water side of the engines ?

How long is this stuff best left circulating ?

Best supplier for these products e.g. via Ebay.

Then for the seawater side I hear Rydlyme is hard to obtain presently, so do I simply use HCL Brick cleaner or something more gentle such as Sulphamic acid.

I suspect its a while since the engines have been properly flushed through.

Thanks.

Dont use OAT in such old engines. Green stuff is still easily obtainable. Reports coming in that OAT causes probs with crystals? abrading seals not designed for it? I would clean by flushing with fresh water first then fo down the route of cleaning with a propietry cleaner. I thought you had recently done a rebuild on the donks?

 

[Beneteau381]

Use OAT only if that is what is specified, other wise use a conventional type. Do not mix the two types.

If using OAT after conventional the system should be flushed with oxalic acid solution, alternatively use a universal, type which is compatible with both types

Unless your tap water supply is very low in dissolved solids use distilled water for dilution , or buy it ready diluted.

Do not extend the intervals between coolant changes because of the risk of contamination with salt water.

If you cannot obtain Rydlyme , or even if you can, consider ProFlush Marine Engine Descaler sold by Force4 and the subject of a recent thread on this forum. Pro Flush alternative to Rydlyme
Alternatively use Fernox DS3 descaler, which is sulfamic acid based,
Circulate until analysis shows no further reduction in acid concentration or until reaction seems to have ceased , but not used all the acid. A useful feature of the Proflush is that it contains an indicator which will show if all the acid has been neutralised.

Weird question and advice considering a thread by both a few years back???Stupidly used OAT coolant for 6 years in a MD2020

 

[robmcg]

I would have thought the old style ethylene glycol antifreeze is the stuff you will need.

 

[VicS]

I would have thought the old style ethylene glycol antifreeze is the stuff you will need.

Practically all the engine antifreeze available in the UK is ethylene glycol based.
The difference between the conventional and the OAT is in the inhibitors.

 

[superheat6k]

Dont use OAT in such old engines. Green stuff is still easily obtainable. Reports coming in that OAT causes probs with crystals? abrading seals not designed for it? I would clean by flushing with fresh water first then fo down the route of cleaning with a propietry cleaner. I thought you had recently done a rebuild on the donks?

That was on the last boat. These seem in good condition.

I will be ordering from Hexseal their basic MEG product sufficient for ~ 50% dilution.

 

[Scarron]

Here you go, instructions from Sseahorse Marine (Steve Atkins) when I picked his brains for my Sabres

• To flush use 2L Prestone or other cooling system flush
• Remove the pressure cap and inside you should see a small (3mm ish) bleed hole between the chambers, clear it with a piece of wire.
• Engine coolant - Use Bluecol 2 year antifreeze for cast iron block and heads, blue colour only, suitable for classic and vintage vehicles, use nothing else.
• Mixed at 55%coolant/ 45% ionised water,
• Take all day to fill otherwise it will airlock.
• 24L capacity? At 55% ratio = 25L required for two engines [5x 5L]

I bought all the flush, coolant etc from Kimber Friction in Southampto.

 

[Bran]

I had similar questions with my 1998 Perkins Sabre engine. Wasn’t sure what antifreeze type was already in the engine so I contacted a few antifreeze companies and asked for their advice as to which of their products were suitable.
I still got a bit of variance from companies, one saying use an OAT, another saying they recommended a HOAT. OAT has a longer life, HOAT is a slightly higher performing product, not quite so long a life. Had some discussions with Comma and Morris Lubricants, I went with a HOAT product that met all the CAT standards, I went to my local truck factors and got the recommended product. Then repeat flushing and refill the new coolant, all has been well since.
I don’t think it’s too critical on older engines that are not as stressed as newer designs, Prestone do a fully universal product but this is aimed at car engines not larger truck engines. I was tempted by this but several years ago I was running a DAF truck with a Perkins 350 hp engine and wanted to do a coolant swap, I was working at some large lubrication laboratories and asked their scientists about antifreeze, their advice was for larger engines use a heavy duty antifreeze as if the engine has wet cylinder liners the engine needs a slightly higher performing product as there can be some acoustic and thermal shocks around the liners that quickly degrade the coolant. This was before OAT products, wish I was still visiting these laboratories but have found several lubrication manufacturers have helpful technical support lines.
Antifreeze selection is now much more complex with all the various types.