CAT 3126 BEST ENGINE COOLANT ADVICE

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John100156

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My Cat 3126's are working well, SW cooling systems fully cleaned and flushed and whilst doing so I fitted new service exchange SW pumps. Completed oil/filter/anodes and now want to flush-out and change the engine coolant, next time out. I have no idea what may have been used previously and if/when it was last changed, nothing obvious from colour of coolant. Engines are both running very well, temps uniform and stable.

So, my question is: What is the best 50/50 pre-mix coolant to use?

The manual is unclear, I was going to buy genuine Cat extended life coolant (ELC) but thought it best to ask others first. Whilst I am not fixated on OEM Products, I do like to fit genuine Cat filters, belts, impellers and the like, Any thoughts or advice welcome as always....
 
I have always used ELC and change every two years as per spec, when we purchased the boat it had different antifreeze in each engine, so changed, cat is pink and others green, so long as its as per spec to ELC, I doubt it matters
 
fred247 said:
I have always used ELC and change every two years as per spec, when we purchased the boat it had different antifreeze in each engine, so changed, cat is pink and others green, so long as its as per spec to ELC, I doubt it matters
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Specs indicate changing ELC ( extended life coolant) after either 12,000 hours or six years?
 
Many thanks to all, and for PM's from rafiki.....

No idea if/when the last owner changed the coolant, so I shall flush-out the system(s) and have ordered 3 x 20L pails of CAT ELC Premix, from Finning. Thank goodness its every 6 years....;-)
 
John100156 said:
Many thanks to all, and for PM's from rafiki.....

No idea if/when the last owner changed the coolant, so I shall flush-out the system(s) and have ordered 3 x 20L pails of CAT ELC Premix, from Finning. Thank goodness its every 6 years....;-)
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Only if you do SOS analysis evey year, otherwise its 3 yrs
 
Relatively straight forward job , managed to get a hose to fit over the drain port and started draining into a 25L rubber bucket which fitted perfectly in a bilge inspection hatch between the engines, I then used a small drill mounted pump to decant from that into a 30L plastic container, I must say the old coolant (no idea of age) looked red, no debris, pistons, con-rods or crankshafts seen in it. Refilled slowly with new Cat ELC coolant using the drill-pump.

Just the gearbox oil change(s) to do next visit, then she should be good for a decent run out in a couple (wishful thinking) of months or so; what was useful, I emailed Twin Disc to seek their advice on the best oil to use in their gearboxes, I told them I was using Exol Optima Marine 123 in the engines, they responded promptly and said their engineering department would check it for me, and surely enough later that day their engineering manager came back stating that 123 would be perfect for their boxes, they also quoted the API class and some other spec., criteria which I cross-checked with my oil spec sheet and all was correct, so they clearly looked it up first - I must say that I was impressed with their service, nice to have OEM approval.
 
Yes any single weight 30 or 40 for Twin disc boxes
I tend to do mine every 2 years or 200 hrs , they do not hold a lot approx 5 L .
The oil extraction pump on the engine has a position valve it’s connected to the G box sump as well as the engine sump , so it’s takes no real effort to change .
Hardly changes colour , just a tad darker with time , pressure are high around 19 bar cruising .Read somewhere it’s the long chain molecules that break down as they are basically crushed and mashed with time .
 
John100156 said:
Relatively straight forward job , managed to get a hose to fit over the drain port and started draining into a 25L rubber bucket which fitted perfectly in a bilge inspection hatch between the engines, I then used a small drill mounted pump to decant from that into a 30L plastic container, I must say the old coolant (no idea of age) looked red, no debris, pistons, con-rods or crankshafts seen in it. Refilled slowly with new Cat ELC coolant using the drill-pump.

Just the gearbox oil change(s) to do next visit, then she should be good for a decent run out in a couple (wishful thinking) of months or so; what was useful, I emailed Twin Disc to seek their advice on the best oil to use in their gearboxes, I told them I was using Exol Optima Marine 123 in the engines, they responded promptly and said their engineering department would check it for me, and surely enough later that day their engineering manager came back stating that 123 would be perfect for their boxes, they also quoted the API class and some other spec., criteria which I cross-checked with my oil spec sheet and all was correct, so they clearly looked it up first - I must say that I was impressed with their service, nice to have OEM approval.
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Well done John. Gearbox oil easy to pump out with the built on pump. Exol 123 perfect for the job. Will smell a bit different to the used engine oil.
 
Thanks chaps for your encouraging comments - as you have suggested above, all very close to OEM data with each box taking 3.07L (the 0.81 gallons on the nameplate was confirmed as US not Imperial) with the minimum oil pressure when cruising high, at 295 psi, or 20.34 bar, so makes perfect sense to change the oil every two years.

I did use the manual pump for the engine oil changes, but for the first GB drain, I may use the sump drain plug at the bottom just to see if any clutches or first motion shafts drain out ;-) In future though, definitely will use the hand pump and will likely do GB and Engine oil changes at the same time, as its the same oil.

Around 30L for an engine and GB together, so for two, that equates nicely to 3 x 20L tubs....!
 
John100156 said:
Thanks chaps for your encouraging comments - as you have suggested above, all very close to OEM data with each box taking 3.07L (the 0.81 gallons on the nameplate was confirmed as US not Imperial) with the minimum oil pressure when cruising high, at 295 psi, or 20.34 bar, so makes perfect sense to change the oil every two years.

I did use the manual pump for the engine oil changes, but for the first GB drain, I may use the sump drain plug at the bottom just to see if any clutches or first motion shafts drain out ;-) In future though, definitely will use the hand pump and will likely do GB and Engine oil changes at the same time, as its the same oil.

Around 30L for an engine and GB together, so for two, that equates nicely to 3 x 20L tubs....!
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Good job John. None of these jobs are particularly challenging, just take time. Saves probably £150-£200 in fees for a technician?
 
I agree - I do still get a lot of satisfaction doing general maintenance jobs though; I replaced the solenoid on the port starter motor recently, which was very easy to access, but had our local engineers 'Tallers Cornet' change the two sea-water pumps, to avoid breaking ribs squeezing down the port side of the port engine....! Belts and GB oil change next visit, and then I know all is good for a decent run.

I fitted new stern glands and sea-cocks just after I bought the boat, about 15m ago, missed the AC SW inlet sea-cock which I will do at next lift for A/Foul.

Desperate to take her out for a decent run, goodness knows when I will be able to get out again.... lets hope we get vaccinated and all is well for a decent run out over Easter...!
 
Belts were easy on the port engine on my boat, but a struggle on the stbd side. Opposite for the coolant pumps, which I had to remove to change the impellers. These are probably good for at least 5 years but I changed at 3. Had to dangle through the saloon floor to get to the outside of both engines. I had a You‘ve Been Framed moment changing the alternator and belt on the stbd engine. Headfirst through the hatch, and went too far, so couldn’t escape. Fortunately my neighbour heard my cries for help and was big enough to haul me out. I was lucky that he didn’t capture the moment for You Tube.
 
That did make me laugh, but I expect it was both painful and somewhat frightening at the time.

Belts on the stbd are very easy to change on my boat but the port has the HW storage cylinder forward so a little more tricky, I think I might leave the impeller change on my port engine to the local engineers, whom are considerably less beamy than I am....!
 
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