Government math?
The importance of coolant flushes
- Thread starter The Raven
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
Government math?
The red RV 'coolant' is a food grade propylene glycol for the water storage tanks. Keeps the tanks from freezing.
I think my math works out, I did some rounding, and it's been almost five years since I last flushed my cooling system, but IIRC the FZJ80 engine cooling system takes ~ 12-13 quarts (~3 gallons) of coolant.
So to put it more simply, pour 1-1/2 gallons of Toyota Red and 1-1/2 gallons of distilled water into the system. Then top off the radiator expansion tank over the next few days with equal parts of Toyota Red and distilled water with what you have left over.
So you bought two gallons of Toyota Red and two gallons of distilled water.
If you start with premixed aftermarket antifreeze from your local parts store you will need to buy 3 gallons (12 quarts) for each complete refill, then another gallon to top off if needed.
I've had good luck/service out of using the Toyota Red, and as others smarter than I have said over the years, the Toyota engineers tested it to be compatible with the rubber components (ie: hoses, heater core O-rings, water pump seals, radiator tank seals), and plastic (heat control valve, radiator tanks), as well as the metals (copper/brass, steel, aluminum, solder of the heater cores) and sensors in the system.
So as a rough estimate, you can buy two gallons of Toyota Red every five years, or buy 3 gallons of premixed non-OEM coolant every year (based on the suggestion to change that out every year). Both options work, I was mostly comparing the costs.
But irrespective of the cost of the coolant up front, the most important part of the equation, IMHO, is the compatibility of the coolant with the components in the system. If using Toyota Red in the proper concentration decreases the possibility of my front heater core from failing by even a few percentage points that's a bonus. FWIW.
So to put it more simply, pour 1-1/2 gallons of Toyota Red and 1-1/2 gallons of distilled water into the system. Then top off the radiator expansion tank over the next few days with equal parts of Toyota Red and distilled water with what you have left over.
So you bought two gallons of Toyota Red and two gallons of distilled water.
If you start with premixed aftermarket antifreeze from your local parts store you will need to buy 3 gallons (12 quarts) for each complete refill, then another gallon to top off if needed.
I've had good luck/service out of using the Toyota Red, and as others smarter than I have said over the years, the Toyota engineers tested it to be compatible with the rubber components (ie: hoses, heater core O-rings, water pump seals, radiator tank seals), and plastic (heat control valve, radiator tanks), as well as the metals (copper/brass, steel, aluminum, solder of the heater cores) and sensors in the system.
So as a rough estimate, you can buy two gallons of Toyota Red every five years, or buy 3 gallons of premixed non-OEM coolant every year (based on the suggestion to change that out every year). Both options work, I was mostly comparing the costs.
But irrespective of the cost of the coolant up front, the most important part of the equation, IMHO, is the compatibility of the coolant with the components in the system. If using Toyota Red in the proper concentration decreases the possibility of my front heater core from failing by even a few percentage points that's a bonus. FWIW.
Regarding the recurrent brown discoloration to coolant. I believe that it may be due to excessive rust in the system which can settle in the bottom of the block & remain outside of the regular coolant flow pattern. It probably forms a tough sediment layer that gets stirred up and diluted into the new fluid during changes. My guess is that it is more likely in a system that has seen additional water added at some point. I've seen it alot in boat motors. (Just my opinion).
When I was baselining my 97 I made sure to drain from the brass plug on the bottom of the block. I then filled it with distilled water and ran for a few days before draining again & adding the Zerex red asian.
Also, like many others on here, I noticed a significant reduction in coolant temps after changing all components of the cooling system. I'm sure I'll have to take the original head off to repair hardened / leaky valve seals one day. However, that can be a planned operation vs. a roadside HG blowup 2/2 overheating.
When I was baselining my 97 I made sure to drain from the brass plug on the bottom of the block. I then filled it with distilled water and ran for a few days before draining again & adding the Zerex red asian.
Also, like many others on here, I noticed a significant reduction in coolant temps after changing all components of the cooling system. I'm sure I'll have to take the original head off to repair hardened / leaky valve seals one day. However, that can be a planned operation vs. a roadside HG blowup 2/2 overheating.
Regardless of whether there was sediment formed, they still deactivate each other.
bloc
SILVER Star
I actually had trouble finding true green coolant locally. Almost everything available was Yellow or designed to "mix with everything".
Ended up ordering zerex "original" coolant on Amazon for $12.99/gal full strength. My understanding is if you decide NOT to use toyota Red the original green stuff is the closest chemistry to what was being put into vehicles in the era our trucks were built. Yes, it does need to have the pH checked occasionally. I ordered test strips for that from Amazon as well. It'll be a year from installing green in Nov.. I'll try to remember to check then.
That said.. my decision not to run Red because of issues finding it when out on a trip may have been illogical.. given how difficult it is turning out to be to find true green coolant locally anymore.
Seems like I did see green pre-mixed.. which would be fine if I'm just topping up.
Ended up ordering zerex "original" coolant on Amazon for $12.99/gal full strength. My understanding is if you decide NOT to use toyota Red the original green stuff is the closest chemistry to what was being put into vehicles in the era our trucks were built. Yes, it does need to have the pH checked occasionally. I ordered test strips for that from Amazon as well. It'll be a year from installing green in Nov.. I'll try to remember to check then.
That said.. my decision not to run Red because of issues finding it when out on a trip may have been illogical.. given how difficult it is turning out to be to find true green coolant locally anymore.
Seems like I did see green pre-mixed.. which would be fine if I'm just topping up.
mypancreasbroke
SILVER Star
Same here about the yellow stuff. 3 local stores I stopped in seemed to be overstocked with yellow, only a gallon or two of green, and another gallon or two of some brand of red. Just finished flushing allll the junk outta my system today, along with phh, other engine compartment heater hoses, rad hoses, thermostat, etc... One more drain of the distilled water then filling up with green for me.
Any tips or pictures of how either of you did the flush kit? I need to tackle this soon and sounds like a good idea for the next time.
The instruction are on the package the flush kit comes in, complete with accompanying cartoons and all.
I use the Prestone brand flush kit on all of my vehicles. Some folks worry (unnecessarily) about the 'Tee' fitting possibly leaking. I have had the kit on my Early model Bronco for over 20 years (same 'T' and cap) and it has never leaked. Over 15 years on my 80 series, no leaks. The Tee is plastic/nylon but does NOT become brittle over time. But IF you are still concerned about it, once you've flushed your system just remove the Tee and replace it with a brass barbed fitting until you need it again. I just leave mine in place.
It is easy to install.
The instructions on how to use the kit are on the back of the package. I use the Prestone brand 'flush' solution as well.
Do this every 2-3 years and your cooling system will stay in tip-top shape. The cooling system on many vehicles is the most overlooked maintenance item.
Do you leave your flush-n-fill kit in place or do you need to remove it and replace the hose after flushing?
Last edited:
Lots of people complaining about how hard it is to find red coolant is ridiculous lol. Its sold at napa/oreilly/walmart/advanced auto in 50/50 zerex/valvoline mix. They are cheap enough to warrant keeping 3/4 gallons of spare in the truck.
Flush coolant when you flush oil. Make it a job-lot along with also checking the diff and gear/tcase fluids. And if you really want to be fussy, fully flush/replace the brake fluid and if you have a manual do the clutch as ell (as on an 80 the clutch and brake hydraulics are totally seperate).
Everyone has a different view of how often to do all this. All depends what sort of driving, how much of it, and how much care you put into maintaining the vehicle overall. Practically every auto parts store here in Australia has both green and red dyed coolants. Diesel landcruisers use red. I use green in my cars. I always buy it as concentrate and mix 1:1 with clean tap water.
Fresh coolant (combined with a full cooling system flush) along with fresh oil (combined with a new filter and full oil system flush) are cheap insurance for an old motor (not far off 660 k km's for the original 1hz in my 80).
Everyone has a different view of how often to do all this. All depends what sort of driving, how much of it, and how much care you put into maintaining the vehicle overall. Practically every auto parts store here in Australia has both green and red dyed coolants. Diesel landcruisers use red. I use green in my cars. I always buy it as concentrate and mix 1:1 with clean tap water.
Fresh coolant (combined with a full cooling system flush) along with fresh oil (combined with a new filter and full oil system flush) are cheap insurance for an old motor (not far off 660 k km's for the original 1hz in my 80).
Last edited:
