Changing antifreeze in Detroit Diesel

[REBrueckner]

Following for 1972 8V71TI's
I'm sure somebody has posted similar before, but I don't remember seeing such and thought others might find it helpful. Total elapsed work time: either one long workday or a day and a half for the more sane owner.

Testing my antifreeze with test strips this past fall I found nitrites were low and so I decided to change the antifreeze entirely as it has been a while...ten years!!!!! ...(yea, I know, NOT classic maintenance procedure!!!)... However, before you judge too harshly and blast me read the rest.....

Two years ago it tested ok.... Nitrites are especially important for cavitation corrosion protection in wet liner engines (53 series and 92 series Detroits, not important in 71 series like mine which are dry liner). I now suspect any low silicate antifreeze is ok in 71 series, but I am NOT going to test that theory...I use only HEAVY DUTY Detroit Diesel spec approved antifreeze...

The prior antifreeze I used was an odd one unavailable now (but which met DD coolant specifications I outlined in other posts ) and which cost only $2 /gal ten years ago as a left over after the winter season. The last of the original containers had a bit of gel formed (maybe two small glops per container) reflecting limited shelf life but I just used the top 3/4 of each container when refreshing my engines at 1 gal per year recently. Anybody know how any "glop" can form in a low silicate antifreeze???

Draining the old stuff : It was clear green all the way, I never did see anything even slightly suspicious and I sampled the intial coolant drain from each engine four or five times to see if any "crud" was in the cooling system....there was none.. running my finger down inside the coolant fill cap into the expansion tank revealed no slime, just a bit of slippery tannish/brown coolant residue (the tan/brown reflecting typical superficial rust corrosion and icky coolant feel).

Frankly I was surprised everything was so incredibly clean and clear (even though I had added a gallon of fresh antifreeze and water annually to keep it "refreshed").

I ended up draining into the bilge, then pumping from there to containers....it was incredibly time consuming trying to catch fluid from individual petcocks one at a time in small containers which would fit under...I gave up after over four hours on one engine!!!!....

Each 1972 8V71TI took a total of about 13 gallons of coolant total ...half antifreeze and half distilled water. I did NOT drain the port side block of either engine as the petcock is so close to the starter I could barely reach it...and figured splashing coolant all over the starter was not within my repetoire of skills. (maybe a half gallon of coolant remained in there judging from the stbd side engine block drain???)

I drained coolant using these petcocks (after removing the radiatior fill cap): at the bottom of the coolant circulation pump discharge pipe, bottom of the oil cooler(right nearby), aft stbd side engine block, rear of each exhaust manifold....five total....These are identified in my DD manuals...Operations and Maintenance.
I also removed my overflow tanks and emptied and cleaned each one by hand..there was some rust residue at the bottom....not enough to measure..a thin film layer in corners....had not cleaned them in a bout three years.

I preheated each engine for easy start and ran each for about five minutes until coolant in the expansion tank was warm (not hot); (coolant circulates slowly even with thermostats closed); drained the antifreeze into the bilge; filled the engine with plain water via a hose...ran again til warm, drained; repeated a second time: drain, water fill,run, drain....First drain coolant had a tiny bit of old antifreeze...was just a bit slippery....second drain had ever so slight green antifreeze tinge, but I could not feel any rubbing wet fingers together...

Final fill:added alternately 1 gal Power Cool followed by one gallon distilled water till full to top...ran engines about ten minutes; lube oil was nice and warm (not mad hot), so I drained and changed it.

[Passages]

That's pretty much how it was done on Passages. I too gave up on petcocks and just drained by disconnecting the lowest hose and letting it freefall to the bilge. I then used my wet/dry shop vac to remove and trasferred to gallon jugs for disposal at our town recycle center.

The only thing I would add is I used some radiator flush after the first water flush. That potion did seem to get a bunch more crud to flush out as flushed rinsate showed lots of rust and black crystals.

It took me about 4 water flushes after adding the cleaner before rinsate was clear.

This job is a royal PITA but something any one of us can handle. I felt better doing it myself as I knew no shortcuts were taken.

BTW, engines ran noticibly cooler after doing this and the raw water loop. See the phosphoric acid cleaning protocol for raw water in FAQ.

[REBrueckner]

Passages...good point regarding the radiator flush....I figured I might do that if crud came on during any drains...

Also I forgot to post above I have had no cooling issues and engines run at same temp as when rebuilt/disassembled and individual components replaced/acid cleaned ten years ago.

As a preventive measure I did acid wash the salt water side, I think last year...it came out clear...


My experience with these old Detroits (including 53 series): you take care of them and they care of you...

[Passages]

[QUOTE=REBrueckner;121816]
As a preventive measure I did acid wash the salt water side, I think last year...it came out clear...
QUOTE]

Really? When I did my annual white vinegar overnight soak of the raw water side, then fired her up to flush, I got a huge plume of white crud out the exhaust. Lookrd like calcium deposits.

[MikeP]

When I did mine in 05 I used DDs "in service" coolant system cleaner for 30 days. Then I changed it all out with Powercool. I haven't checked the coolant with strips since I changed it and I guess its' something I should do. I'll add it to the list for this spring.

[chris piazza]

Hey Rob I dug up an old thread as I am getting ready to change my coolant and I have one question for you,, how much coolant will it take before you start it to allow the theromstat to open to fill it the rest of the way. Or a better question is which/how is the best way to re-fill?

Chris
Superior Nights 53C

[andylou]

Hi guys,

I've just changed out one engines worth of coolant, and will do the other this weekend. I've a question on the coolants. I chased down the specs today and now am really confused! I put Zerex Original in the motor I just did the fluids on. Valvoline state that Zerex Original meets Detroit Diesel spec 7SE298. The Detroit Diesel coolant guide says that it recommends power cool, or a commercial equivelent to TMC RP-329 Type A. All I want to know is the Zerex Original a suitable coolant for the 92 series Detroit motor? It has a very low phosphate level, has no nitrates and has all the inhibitor additives. It is the original 'green stuff'. What are your thoughts?

[Walter P]

I wouldn't take a chance on using other than the DD Powercool material that is specified for DD's. The Detroit engines are rather delicate as regards the use of proper coolants. I am not a scientist, but it has something to do with cavitation or corrosion that can actually poke holes through the sleeves. This is especially of concern on wet sleeve engines, which is all Detroits except the 71 series.

Walt

[REBrueckner]

I did a lot of research and posted all brands ok for DD at the time.... check "antifreeze" or "coolant for Detroit Diesels" ...

The one CRITICAL factor is LOW SILCATE for ALL detroits....Go with those those that says HEAVY DUTY and DETROIT DIESEL on the conatiner....You can also read spec 7SE298 on line....search DETROIT DIESEL COOLANT specifications or similar...

[SKYCHENEY]

The green stuff may be okay for 71's but I would only use Powercool in 92's.