Advice flushing 31qt. diesel cooling system?

[pmwalter]

Gearing up for a marathon coolant flush this Saturday. I need to flush my 7.3L Diesel engine with a 31qt. capacity.

I use distilled water for all my other cars. I'm worried about how much water I will need for this system. If I flushed it three times it would be 24 gallons of water, assuming I get most of the water out.

Anyone have experience flushing a large system like this?

 

[DR Racing]

Use tap water to flush and distilled water as the coolant mix. Dan

 

[Winston]

Just drain and refill.

 

[BEKAIR]

You will not get all the water out no matter how many flushes you do.

Are you changing coolent from OEM - IE 99 to 2002 was green low sil. e.g. - 2002 up gold go5.

Good idea is flush with tap water - then finish up with 2 or 3 flushes with distil - the add your 2 gals. A/F and top with distil - using you c s a if you use green.

Should use up abt 20 gals distil (less if staying with same a.f. for good flush.

Barry

 

[Bio-T]

pmwalter,

This is a good article written in 2002 on the complete cooling system including the flush of the 7.3 PSD. Very interesting and has some pictures. I hope this helps:

7.3L Coolant System and Flush

 

[PaJohn]

pmwalter,
What a coincidence. Just bought a 99 F250 PSD for my son. Have already done oil and ATF change, Coolant was next on my list. Thinking of using the Rotella ELC and will need to perform complete flush as well. Let me know how it goes

 

[Ray H]

The main things I disagree with in the article are the statements that silicates are only necessary with aluminum parts and the recommendation to use tap water for the flush. Silicates, introduced by Prestone*, were used as long ago as the late '50s - and aluminum was not an issue at that time. The other thing I question in the article is use of tap water for the flushing. While tap water is easier, there is inevitably some mineral content left behind to promote corrosion. (and THAT doesn't take much) I understand we're talking ~24 gallons, but that's less than $17.00 to do it right. Averaged over 60,000 miles, it's cheap.

*Prestone's automotive antifreeze products are now completely silicate-free. Dunno about their truck antifeeze products.

 

[wulimaster]

Ditto for my 2000 7.3. I will be ordering 4 gallons of the new amsoil antifreeze and will be glad not to have to add SCA anymore. Mine says 33 quarts. I figure 16 qts (4 gals) of antifreeze ought to do it. I was looking up howto change it over the last day or two and noticed that some have a cylinder drain plug also.

I will be using tap water to flush until clean and then use the distilled water to flush out the tap water twice. Then fill with 4 gallons antifreeze and top it off with distilled. If it lasts as long as Amsoil says I shouldn't need to do another drain until 2012. I doubt I will reach 250k miles in that time.

I really don't look forward to this and 2012 will be too soon for a repeat.

 

[pmwalter]

Well I did it. It took me most of today and a few hours last night. It took me six full flushes to drain out most of the green stuff. Then I decided to use one chemical flush. Then I followed that up with another flush. Then I flushed with distilled water. I topped it all off with G05 and distilled water.

I'm pooped! That was wet and boring. Hopefully I did it right so I won't have to visit that project any time soon.

 

[wulimaster]

I finished mine up about an hour ago. Took about 3 hours and many flushes. I filled and flushed 3 times with tap water till it ran clear and then did almost 5 gallon fills and drains with distilled water. After two drains of the distilled I filled it with 4 gallons of Amsoils new stuff. It is still down about 3/4 gallon and I haven't decided if I will buy another gallon to top it off or just put the 3/4 gallon of distilled water in.

I guess I'll check on how much my mother in law's car takes and use what she doesn't need and top off the remainder with distilled.


NIce Bright yellow color.

 

[Stinky Peterson]

What does Amsoil use for SCA that you won't ever have to add?

 

[wulimaster]

Originally posted by Stinky Peterson:
What does Amsoil use for SCA that you won't ever have to add? [/QUOTE

It is a propylene glycol with a proprietary poly organic acid formulation. It says no supplemental SCA's needed.

750k miles/7 years for over the road trucks
250k miles/7 years for gasoline vehicles