3126TA Coolant

HUMPH

HUMPH

Well-Known Member
Nov 4, 2009
7,618
SF BAY AREA
Boat Info
2003 410DA
2009 Walker Bay 13’
Engines
CAT 3126TA's 350HP/
50HP Honda
Can anyone tell me how much coolant I need to replace my existing CAT ELC? I know I can add extender again but want to replace all of the coolant anyway. Also, what is the best way to extract ALL of the old coolant?
Thanks in advance Frank!
 
The manual says 30 qts per engine......60 for both or 15 gal. I usually just buy 3 cases or 18 gal. I don't mind having some extra ELC here for in Tennessee because I use the Cat coolant in my tractors, backhoe, Bobcat and diesel truck.

If your coolant is maintained and hasn't broken down, you can just drain it and replace it with fresh ELC. If the old coolant is slimey or cloudy, then you need to flush the engine. To drain the coolant, remove the radiator cap from the tank then remove the drain plug. The drain plug is in the bottom bend of the 1-1/4" brass tube leading out of the heat exchanger.........outside on the port engine; inside on the stbd. The plug is hard to see so run your hand down the back/bottom of the tube.....it looks like a pipe plug but it is really an o-ring plug, so check the o-ring carefully and replace it if necessary..........if you are going to the Cat store for coolant, just get 2 new plugs w/o-rings because replacing a leaky o-ring means losing a gallon or more of the coolant you just replaced....plus it takes 3 hands.

I'll tell you now that is is virtually impmossible to catch all the coolant because there is very little space under the drain plug....think wet/dry shop-vac.

Also, Caterpillar has changed the packaging and the part number on ELC.......the new part number is 238-8648.

There ya go, Ken.........
 
Frank,

How often should I be changing out the coolant? I've owned the boat 4 years and never even thought about it.
 
If you are using Caterpillar ELC.....extended life coolant..... (red, pre-diluted part number 101-2844/238-8648) the coolant has a 6 year life. At year 6 you can extend the coolant for 3 more years by adding the Caterpillar Extender, however, Cat recommends that you begin testing the coolant for SCA's (supplimental coolant additives) annually once you add the extender.

If you are not using Cat ELC, then you should be using SCA's and testing the coolant (Cat sells a kit for testing) regularly and adding SAC's when needed.

I am a bit more conservative than this. The Cat ELC is so easy to use and does a perfect job of protecting your engines that I only use it and I change the coolant every 5 years instead of 6. The red ELC makes your coolant a check the level in the overflo jug and forget it thing. Using any other coolant puts you in the SCA checking business which means keeping fresh reagent strips and checking the coolant about 2X a year. It is just so much easier to change the coolant early and use the ELC......and then revisit it in 2023.

One more point.......the additive package in diesel coolant is a critical item. It does 2 -3 basic things....stops foaming, stops cavitation, prevents corrosion. Cavitation is an engine killer. It causes pitting in the liner or cylinder walls which eventually break thru and allow compression to leak into the coolant.....end result is a new engine and a $25K bullet aimed at your pocket book. Other coolants are available, but they do not offer the same quality or conveneince as Cat ELC: Cat has a non-ELC version that is not prediluted, Cummins Fleetguard Compleat coolant is good and I understand Cummins now has an extended life coolant. The Cat ELC is so good, so convenient and so cost effective (5-6 year life, no SCA cost, No SCA testing and no maintaining SCA testing strips) that I have just never looked into anything else.

Hope that helps catch you up on the 3116 coolant story.
 
As coolant ages it tends to leave a "slime" on the surfaces that it transfers heat from like the cylinder walls and heat exchangers. Consequently, the efficiency of heat transfer is compromised. You should flush the engine cooling system completely if draining the coolant. I don't know what my mechanic used as a flush media, some kind of a detergent or just tap water, but we saw an improvement in cooling temperature stability. There was significantly less fluctuation in temperatures between low load and higher load conditions. As a note I didn't have any record of the coolant being changed before buying the boat and ran the boat for a year with analysis of the coolant and ELC extender; so, I had no idea how old the coolant was..... This was on my 400DA with the Cat's.
 
fwebster said:
The manual says 30 qts per engine......60 for both or 15 gal. I usually just buy 3 cases or 18 gal. I don't mind having some extra ELC here for in Tennessee because I use the Cat coolant in my tractors, backhoe, Bobcat and diesel truck.

If your coolant is maintained and hasn't broken down, you can just drain it and replace it with fresh ELC. If the old coolant is slimey or cloudy, then you need to flush the engine. To drain the coolant, remove the radiator cap from the tank then remove the drain plug. The drain plug is in the bottom bend of the 1-1/4" brass tube leading out of the heat exchanger.........outside on the port engine; inside on the stbd. The plug is hard to see so run your hand down the back/bottom of the tube.....it looks like a pipe plug but it is really an o-ring plug, so check the o-ring carefully and replace it if necessary..........if you are going to the Cat store for coolant, just get 2 new plugs w/o-rings because replacing a leaky o-ring means losing a gallon or more of the coolant you just replaced....plus it takes 3 hands.

I'll tell you now that is is virtually impmossible to catch all the coolant because there is very little space under the drain plug....think wet/dry shop-vac.

Also, Caterpillar has changed the packaging and the part number on ELC.......the new part number is 238-8648.

There ya go, Ken.........
Click to expand...
Hmmm, why did I know you would chime in? Thanks for saving me from dragging the manual out. Sounds like a fun Saturday project! My coolant looks great and tests fine but I am in my 7th year in a 15 year old boat and just want to do it. I get good pricing from CAT so it shouldn’t be too bad cost wise.
 
ttmott said:
As coolant ages it tends to leave a "slime" on the surfaces that it transfers heat from like the cylinder walls and heat exchangers. Consequently, the efficiency of heat transfer is compromised. You should flush the engine cooling system completely if draining the coolant. I don't know what my mechanic used as a flush media, some kind of a detergent or just tap water, but we saw an improvement in cooling temperature stability. There was significantly less fluctuation in temperatures between low load and higher load conditions. As a note I didn't have any record of the coolant being changed before buying the boat and ran the boat for a year with analysis of the coolant and ELC extender; so, I had no idea how old the coolant was..... This was on my 400DA with the Cat's.
Click to expand...
Thanks Tom!
 
My 450DA had 75 hours on the engines when I bought her. Tthe coolant was OEM fill and I ran ran her fromOctober to December when I did my annual service. Even thogh Cat says ELT can be run for 6 years bedfore replacing or extending the life with their Extender. The coolant looked and tested great but I replaced it at the 5th year mark. I checked the coolant visually and replaced it every 5 years while I owned the boat. the coolant looked new and and didn't show any solids or slimy residue on the interior surfaces of the cooling system, so I never saw the need to run a coolant flush thru the system. Cat does recommend running their coolant system flush mixed with distilled water when you change the coolant but I never did because I never used anything but Cat ELC in my engines. The engine surveyor wanted to have the coolant analyzed by the Cat SOS labm when we sold the boat and it came back clean and no recommendation to do anything but change it again in 6 years.
 
Setting up my PM schedule for the winter.

I replaced my ELC in 2019, so I'm "due". I know the coolant I replaced in '19 was old and a there was a little slime in it. This time I intend to flush, then refill. Anybody know the right CAT part number for the flush?

Also going back to the 185* thermostat if I can get them.
 
k9medic said:
Frank,

How often should I be changing out the coolant? I've owned the boat 4 years and never even thought about it.
Click to expand...
You can purchase coolant test strips. That will give you an idea on how your coolant is holding up.
 
dtfeld said:
Setting up my PM schedule for the winter.

I replaced my ELC in 2019, so I'm "due". I know the coolant I replaced in '19 was old and a there was a little slime in it. This time I intend to flush, then refill. Anybody know the right CAT part number for the flush?

Also going back to the 185* thermostat if I can get them.
Click to expand...
CAT P/N 4C-4611. From my records.
 
dtfeld said:
Setting up my PM schedule for the winter.

I replaced my ELC in 2019, so I'm "due". I know the coolant I replaced in '19 was old and a there was a little slime in it. This time I intend to flush, then refill. Anybody know the right CAT part number for the flush?

Also going back to the 185* thermostat if I can get them.
Click to expand...

I have the 195’s ready to be installed (for a year) and haven’t managed to get around to it. Any issues with them or you just prefer the extra buffer until overheat?
 
Strecker25 said:
I have the 195’s ready to be installed (for a year) and haven’t managed to get around to it. Any issues with them or you just prefer the extra buffer until overheat?
Click to expand...
Nothing negative to report as far as operation, but yes, I prefer to have the extra buffer back.
 
ttmott said:
CAT P/N 4C-4611. From my records.
Click to expand...
Thanks Tom.

Looks like CAT updated to a new part number. 4C-4611 is showing Obsolete, but looks like it was a gallon of the stuff. New Part Number is 4C-4610 and $22.56 for a quart. Maybe they went from a premix to a concentrate?

I'm assuming this gets mixed with water, and run hot for 90 minutes but not sure the ratio product/water...Hence, how many quarts do I need?

Anybody have experience with this stuff or a link to the instructions?
 
waterman said:
You can purchase coolant test strips. That will give you an idea on how your coolant is holding up.
Click to expand...
I had the ELC tested via SOS last year no issues, so I likely can get away with the current ELC for another year or test and add SCA, but I know the last time I changed I had some slime/rust and I intended to do a complete flush/clean at the 5 year mark.
 
Strecker25 said:
I have the 195’s ready to be installed (for a year) and haven’t managed to get around to it. Any issues with them or you just prefer the extra buffer until overheat?
Click to expand...
No issues other than looking down checking temps under way, seeing 195° and thinking oh shit I'm running hot.... Lol
 
Went to the local CAT dealer today looking for some things for the winter MX projects. A couple of things I learned.

1. The lower temp (185*) thermostats are not available. We spent about an hour looking for a compatible lower temp thermostat, but we could not find one in CAT's system. The currently specified one is Part # 284-5421 and is specified for complete opening at 97*C or about 201*F I can confirm my engines run at about 203 on my digital engine temp gauge so this seems reasonable/accurate.

2. The cooling system cleaner 4C-4610 is mixed 1 qt to 30 qts of water. 3126 is roughly 28 Qts, so (1) 1 Qt bottle and fill up the system with water, and run for 90 minutes. However, its not in stock and CAT suggested any radiator cleaner product from a auto parts house.
 
Been running 195 thermostats here in SW Florida for nearly 2 years with no adverse affects.

I posted pics awhile back after running the Florida Loop - 16 nights out on the boat and nearly 700 miles - THE TRANSOM & GUNNELS WERE SURPRISINGLY CLEAN.

Dunno if this had anything whatsoever to do with the 195 T-stats, as the valves and overheads were run the year before and all coolers cleaned/serviced and engines brought back to baseline, or maybe it was the entire combination.... dunno.

All I can say is that I can report that down here in the warmer waters the 195 units are fine on the 3126

BEST !

RWS
 
Maybe A Dancer said:
Been running 195 thermostats here in SW Florida for nearly 2 years with no adverse affects.

I posted pics awhile back after running the Florida Loop - 16 nights out on the boat and nearly 700 miles - THE TRANSOM & GUNNELS WERE SURPRISINGLY CLEAN.

Dunno if this had anything whatsoever to do with the 195 T-stats, as the valves and overheads were run the year before and all coolers cleaned/serviced and engines brought back to baseline, or maybe it was the entire combination.... dunno.

All I can say is that I can report that down here in the warmer waters the 195 units are fine on the 3126

BEST !

RWS
Click to expand...
I was surprised to learn the CAT temp spec on this part# is 97*C or about 201*F, not 195*F and certainly hotter than the original which was supposed to be around 185*F. I think my biggest concern is if there is a cooling system issue, not a lot of headroom/time between 201* and trouble.

Would the extra 15* from the original help in a real world situation? I kinda doubt it. I think the first clue any of us will get will be the Sea Ray Monitor system going off.

When I do the cooling system, I’m going to replace with the exact same 97*C part CAT specifies.
 
I noticed that on the box too. Bad things happen at what, 210? 215 maybe?

I'm all about a full clean burn but that's scary close
 
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