Coolant Questions

[whistlerxc]

I know that this topic has been covered probably many times before, but I can't seem to find a reference to my specific question. I drained what I thought was all the coolant from my Perkins Sabre and then proceeded to add fresh coolant. My new coolant is a different color (red vs. the old coolant- green) but meets specs. for my engine. But now i see that I must not have drained ALL the old coolant as I can only add about 15L when capacity is 25L. The result I guess is that I have a mixture of green (unknown kind as this is a new boat to me) and red.

Is this a problem? And is anyone familiar with the Perkins Sabre M135? I drained the heat exchanger as it appeared to be the lowest point. Is there another drain plug that I am missing?

 

[djones44]

Is this a problem? And is anyone familiar with the Perkins Sabre M135? I drained the heat exchanger as it appeared to be the lowest point. Is there another drain plug that I am missing?

There is probably one lower down, I deliberately avoid one on my TAMD40B because rebuilders warn that if you ruin that by forcing it open, you may have to replace the entire exchanger. Don't start a fight with an old boat engine...

So I avoid that nightmare and open the drain on the HE itself, higher up, and then replace the fluid gradually, doing a chemical flush in between, then a water flush, then the final fill with uniform coolant.

Water is the most efficient coolant anyway, so I view it as a process, more than a task like the oil change. I do tend to run fresher coolant this way, and I swapped out my old thermostats this month en passant. The mollusc growing out of one of them was heartbroken.

 

[whistlerxc]

Thanks for taking the time for some advice. I feel I can open the lowest drain plug on the HE without much danger. I felt it was at the lowest point of the system, but obviously not as I only have about 3/4 of the old stuff out. The manual gives another location 'on the block' itself, but I cannot find it.

I am not clear on your process of flushing. As I read you, you drain what you can, then replace what you took out with new coolant, then do a chemical flush, then a water flush. When I think of a 'flush' I think that this means you take out all the old coolant, add what ever liquid you are flushing with, then remove all of that material and then add new coolant in a now empty and flushed system. If I read you correctly, it seems like you are not removing all the flushing material in between cycles. Do you see my confusion?

And of course, I was hoping to skip the flushing of any kind and just drain and then refill.

Lastly, any thoughts of the now mixture of red and unknown green coolant? I suppose the safest thing to do is to again drain what I can of my newly added red coolant, try to find a another drain plug, flush the system with something, and then start again.

 

[READY]

Not an expert but from what I read it appears red and green are 2 different formulations and at best mixing is not advisable and at worse it is going to cause your engine to fail for all sorts of reasons. Probably that is not too much of a concern but in the interest of piece of mind and given cost is low I would probably just flush it all with clean water and drain and refill with what is specified by the engine manufacturer.

 

[firehoser75]

Whistler,
Some engines are "coolant sensitive" and some are not. My Cummins 6BTA was not.

However, some coolants DO NOT PLAY WELL with some other coolants. When changing to a new coolant (chemistry) it is always best to drain completely, then flush with a flush formulation or clean (distilled) water, and if using the chemical flush, follow with a distilled water flush. Then refill using the new coolant (water mixture).

Leaving what you did, could cause problems. In my generator, I just changed to a new coolant several years ago (same as you green to red) and I experienced some "gelling" of the coolant visible inside the radiator cap. I had to start from scratch with the above steps (completely flushing several times). While you are at it, and for little cost, replace the thermostat and rad cap.
Check with a reliable source (in this case maybe Perkins) to determine if your engine requires a specific coolant, and use distilled water for diluting to the 50/50 mixture.
Good luck.

 

[Bmarler]

I’m no expert either, but I have had bad reactions mixing “universal” coolants with both newer stuff (oat) and older stuff. I have a lot of different brands of motors and they all seem to want different coolants. I only use manufacturers recommended coolants any more, and don’t mix in anything else.
A thorough fresh water flush when changing coolant is a fantastic idea.

 

[koliver]

If you have any of the original green coolant that has been drained out (my luck would see all of that already disposed of, yours may be better) pour some of the red into it and see if there is any obvious refusal to mix. With no apparent issues, you might see if you can do another drain, followed by a flush, followed by filling with only one colour.
Most HEs are elevated so the top of the HE is even with or above the highest coolant passages in the block or head. You want to look for the drain cock on the side of the block, well down towards the bottom of the block. There is one, you can be sure.

 

[whistlerxc]

Thanks to all for taking the time to give me your perspectives!

 

[Slowmo]

It really is a function of what you put in. The color is just a dye to identify the coolant. All are ethylene glycol based but the corrosion inhibition package differs between 'conventional' and 'long life' coolants (Green and Pink). Long life coolants use an organic acid based inhibitor system. Mixing coolants will NOT destroy your engine, period. However, mixing the different inhibitor systems degrades the corrosion inhibition.
Generally, no more than 25% dilution is recommended.

 

[rslifkin]

I've seen some cases where mixed coolants were fine, but others where it made a nasty brown sludge.

Personally, if I'm not 100% sure what coolant was in a system, I just flush thoroughly with water, then re-fill with an appropriate coolant. Easiest way to get 50/50 after a flush is to drain as much of the water as you can, add 1/2 the system capacity worth of concentrated (not mixed) coolant, then top off with water. It'll mix when you run the engine, and you don't have to worry about accidental dilution from leftover water.

 

[Portage_Bay]

Here's a link to a description of coolant gel caused by mixing incompatible coolant types. Silicate Gelation in Heavy-Duty Diesel Engine Cooling Systems Written for the Society Of Automotive Engineers. Note the date of 1986. The reason I say that is a few years back when researching the issue I found a good source that discussed when gelling incidents were happening and the likelyhood they may not happen currently. Much of the older coolants incompatible with the newer are now long gone. I have not been able to find that source again. Time marches on.

I will say that I have seen one extreme example of coolant gelling. On a boat I was inspecting for my employer's purchase. A generator using a grid cooler had jelled coolant. Beyond gel, it was almost a rubbery substance completely blocking the grid cooler passages and the engine passages. The result was a motor destroyed by overheating and a grid cooler requiring expensive clean up.

So while it is not likely it is possible. For my money if I am not 100% sure of what coolant is in there I will flush and re-fill with new. It's a simple risk/benefit calculation. Hundreds of $$ to drain, flush and re-fill vs tens of thousands of $$$$ to repower.

On a final note. Don't trust the color to tell you what's in there. It's only a dye, not the actual chemicals. Another poster in another thread discussed that in some detail.

 

[rslifkin]

On a final note. Don't trust the color to tell you what's in there. It's only a dye, not the actual chemicals. Another poster in another thread discussed that in some detail.

Absolutely this. There are cases in the coolant world of totally different coolants that are almost the same color. And also cases of the exact same coolant dyed different colors as coolant for different OE engine manufacturers An example of that second thing is Zerex G-05, it's light gold. Ford Motorcraft Gold is G-05, same color. Mopar pink HOAT coolant is also G-05, but it's dyed pink instead of a pale gold color.

 

[Comodave]

I am going to replace the coolant in my 450 Cummins this spring. Cummins makes a flush called Restore. There are 2 versions the flusher, one to remove gel and one that works better for removing rust and scale. Then you flush with water before adding the new coolant. My engines have wet liners so the coolant is critical to keep the liners from getting pinholes from cavitation. Then you change the coolant filter and check the SCA level to make sure it is in the proper range.

 

[C lectric]

Portage Bay




******I drained the heat exchanger as it appeared to be the lowest point. Is there another drain plug that I am missing?*******

I cannot tell you where the block drains are but they will be present. THey may not be at the absolute bottom depending upon engine tilt but close.

CLosely examine both sides. THey may simply be closed with a screw in plug.

 

[Island Cessna]

Portage Bay




******I drained the heat exchanger as it appeared to be the lowest point. Is there another drain plug that I am missing?*******

I cannot tell you where the block drains are but they will be present. THey may not be at the absolute bottom depending upon engine tilt but close.

CLosely examine both sides. THey may simply be closed with a screw in plug.

No coolant in the block lower than the water pump inlet will drain via the heat exchanger. To drain it all you need to find the plug or drain tap on the side of the block. It should be clearly identified in an operators manual.

Photo is from manual for a 4 cyl showing the block drain. A manual for a 6 cyl turbo says:
“Caution: The closed circuit system cannot be drained completely. If the coolant is drained for engine preservation purposes or for protection from frost, the coolant system must be filled again with an approved antifreeze mixture‚ see ‘Coolant specification” on page 51 for details of the correct coolant to be used in the circuit.”.

You need the Operator’s Manual for your model! You should find it on line if not with the boat.

 

[mcarthur]

Good to see someone else with the M135 :smile:

There's three drain plugs, one on the coolant filter and one under the heat exchanger, and one final on the cooled manifold assembly. Don't forget to take off the coolant header filler cap too so that suction is lessened. The Users Handbook has the pictures. PM me if you need.

Edited: The M135 needs extended life coolant, 50:50 mix with "clean water" but don't mix it with old coolant. The manual, which is old, mentions Halvoline XLC is ok too. I'm using another XLC as they are much more common today than they used to be. There is aluminium in the cooling circuit, so have to be careful of the anti-freeze. The nice thing is that the coolant should last 6 years/6000hrs!

 

[steelheder]

I would strongly recommend you drain and flush your cooling system, then refill with a proper coolant based on manufacturer recommendations. You stated you have an unknown coolant in the green color variety. Coolant is critical in diesel engines and is fairly cheap in the scheme of things. While you may be ok, you may not. The 'may not' is really expensive so if it was me, drain, flush, flush and refill with good coolant.

 

[Comodave]

I would strongly recommend you drain and flush your cooling system, then refill with a proper coolant based on manufacturer recommendations. You stated you have an unknown coolant in the green color variety. Coolant is critical in diesel engines and is fairly cheap in the scheme of things. While you may be ok, you may not. The 'may not' is really expensive so if it was me, drain, flush, flush and refill with good coolant.

Yup. That is exactly what and why I am going to do my engines this spring.

 

[Slowmo]

Here's a link to a description of coolant gel caused by mixing incompatible coolant types. Silicate Gelation in Heavy-Duty Diesel Engine Cooling Systems Written for the Society Of Automotive Engineers. Note the date of 1986. The reason I say that is a few years back when researching the issue I found a good source that discussed when gelling incidents were happening and the likelyhood they may not happen currently. Much of the older coolants incompatible with the newer are now long gone. I have not been able to find that source again. Time marches on.

I will say that I have seen one extreme example of coolant gelling. On a boat I was inspecting for my employer's purchase. A generator using a grid cooler had jelled coolant. Beyond gel, it was almost a rubbery substance completely blocking the grid cooler passages and the engine passages. The result was a motor destroyed by overheating and a grid cooler requiring expensive clean up.

So while it is not likely it is possible. For my money if I am not 100% sure of what coolant is in there I will flush and re-fill with new. It's a simple risk/benefit calculation. Hundreds of $$ to drain, flush and re-fill vs tens of thousands of $$$$ to repower.

On a final note. Don't trust the color to tell you what's in there. It's only a dye, not the actual chemicals. Another poster in another thread discussed that in some detail.

Just a comment. Yes SAE papers are a good source of info, I've even authored some, but this is a 1985 paper and the issues discussed there are really not related to mixing OAT with 'conventional' coolants. OAT were developed after this paper was written. The phenomena described in the paper is distinct from mixing OAT and conventional antifreeze, which won't in itself cause gelling. When developing formulations it is assumed some degree of mixing will occur when changing from conventional (green) to OAT (generally dyed pink) coolants.

 

[Portage_Bay]

Just a comment. Yes SAE papers are a good source of info, I've even authored some, but this is a 1985 paper and the issues discussed there are really not related to mixing OAT with 'conventional' coolants. OAT were developed after this paper was written. The phenomena described in the paper is distinct from mixing OAT and conventional antifreeze, which won't in itself cause gelling. When developing formulations it is assumed some degree of mixing will occur when changing from conventional (green) to OAT (generally dyed pink) coolants.

Yes I agree and said as much though not as technically correct as your post. I will note the gelling I discovered was in 2016. The boat had been in service within 2 yrs prior. When unsure what is in the engine especially an older installation which is what the OP is facing a flush and refill is good practice.

 

[whistlerxc]

Again, thanks to all that took the time with their advice. I do have a manual for my engine which has been quite helpful. However, the diagram showing the drain plug is not detailed enough to allow one to find it easily. Island Cessna copied one and sent it along (see above) and that diagram offers a bit more detail so thanks for that (it is on the right side of the block I see, above the starter motor).

I will take everyone's advice and drain the coolant- this time completely and flush it. I will remove the thermostat to not only inspect it but to allow a better drain and flush. Then refill with probably the same coolant I purchased (red coloured but rated for diesels). BTW- the manual, written for my circa:year 2000 engine does not specify what kind of coolant, only that it is 50/50 mixture and either 'glycol or propylene glycol' so unless I find and purchase Perkins' particular brand- "Powerpart" I am forced to go with what seems to be a good product to substitute.

I also have a bus heater and a engine heated hot water tank that will have to be drained again. All totalled is over 25 litres.

Another question: how long do you run your engine with a fresh (distilled) water flush? Do you go 20 minutes? 1 hour? Do you strongly reccommend a chemical flushing agent also (with a last flush of water)?

 

[Comodave]

This is the procedure for flushing my 6CTA Cummins engines. Restore is the Cummins brand flushing agent. You may use a different brand but this may give you an idea as to the procedure.

1. Drain the cooling system and dispose of used coolant. Backflush the system.
2. Immediately add 1 litre of Restore or Restore Plus for each 10-15 litre of cooling system capacity and fill the system with plain water.
3. Turn heater temperature switch to high to allow maximum coolant flow through heater core. Blower does not need
to be turned on.
4. Run the engine at normal oper ating temperature for 2 hours.
5. Drain and flush the system with plain water and change your water filter if applied.
6. Refill with a fully formulated Coolant (such as Fleetguard

 

[Capt Ray]

I won't try to add anything new to all that has been said of the coolant itself.

But I will add that while you are going over all the components with a fine tooth comb (and camera) looking for drain holes, etc. it would also be good to ensure you know where all the zincs are that should be changed out periodically. Keeping a cooling system in good condition involves maintaining all your zincs as well!

 

[Brooksie]

Are you measuring what you drained by what you put back in? This may be wrong b/c you may be able to fit more coolant in after all the air pockets are worked out and the thermostat is opened.
If you try again, flush with fresh water, bring up to temp and top off. Measure what you remove. Do this 2-3 times making sure you have just clear water. Then drain and install 100% AF (1/2 the capacity) and top off with distilled water check with AF tester ($7). Check a couple more times after running under load.

 

[CarlF]

You will have to bleed the system to get rid of air that will keep the coolant from circulating. Run for 20 minutes with the cap loose. Let cool. Top off and tighten cap.

If your bus heater or any other stuff is higher than the cap, remove a hose at the highest point until no air. It sometimes takes a few tries.

I would also do this for the flush.

 

[C lectric]

If you are trying to work out air bubbles then push up the engine revs to more than just an idle. The coolant pump will move far more coolant at 12 or 1300 revs than at idle.
That will help push the bubbles out.
The faster heating will also help as the air will expand past its trapped spot.

Just do not fill the heat exchanger to full. Leave about 2 " to the filler neck or those bubbles will blow A.F. out covering you and the engine.
As the level drops with each bubble surge then some A/F can be added but be carefull to not bring the level up to much , yet.

I have burped even more by pushing revs up even more , 1500m or there about, once the first air bubbles vacate.

After that it may take adding more coolant and taking the boat out for a proper heat up run. Then once cooled add what is needed to get the normal coolant level back.

 

[Cartouche]

I know that this topic has been covered probably many times before, but I can't seem to find a reference to my specific question. I drained what I thought was all the coolant from my Perkins Sabre and then proceeded to add fresh coolant. My new coolant is a different color (red vs. the old coolant- green) but meets specs. for my engine. But now i see that I must not have drained ALL the old coolant as I can only add about 15L when capacity is 25L. The result I guess is that I have a mixture of green (unknown kind as this is a new boat to me) and red.

Is this a problem? And is anyone familiar with the Perkins Sabre M135? I drained the heat exchanger as it appeared to be the lowest point. Is there another drain plug that I am missing?

No Green is universal sometimes yellow and red is long life do not mix them

 

[whistlerxc]

Thanks again to all. I DID find the block drain plug as others suggested I insist on doing. After draining, I did a proper flush. I think I am ok for at least a couple of years now. BTW as a note to Capt. Ray- thanks also for the reminder but in my case, this Perkins engine does not have any zincs as strange as it seems. Cheers to all.

 

[Island Cessna]

Thanks again to all. I DID find the block drain plug as others suggested I insist on doing. After draining, I did a proper flush. I think I am ok for at least a couple of years now. BTW as a note to Capt. Ray- thanks also for the reminder but in my case, this Perkins engine does not have any zincs as strange as it seems. Cheers to all.

The only zincs you might find will be in the raw water piping, which will not require you to disturb your new coolant! Perkins used some copper piping in the original raw water system and there were 2 or three small pencil zincs in my system, one in a small nipple on the side of each section of pipe. The oil cooler has one as well.

I have re-plumbed all of my raw water in hose and Marelon fittings, leaving only the oil cooler zinc.

 

[whistlerxc]

Thanks again. I will look for those zincs in the oil cooler and raw water intake hoses.