Does Coolant Capacity Include Overflow Tank?

Messages
11
Hi All,

I'm going to be doing a coolant flush on my 2008 Pontiac Vibe. My plan is to drain as much coolant as I can from the radiator, block, and heater core, then fill up with distilled water 2-3 times until it comes out clean, then refill with coolant. I plan to measure how much coolant I get out at first (I assume it won't be 100%) to give me some idea how much water will be left in the system after the last flush so I can get the ratio right with concentrate. The manual says the coolant capacity is 6.9 quarts. My question is, does this include the fluid that's in the overflow tank, or just in the radiator/block/core?

Thanks in advance!
 

ssalvat

Thread starter
Messages
11
I appreciate the responses, but they're starting to get away from my original question. I'm really just trying to figure out whether the coolant capacity listed in the manual includes the overflow tank or not (and, I guess, would that mean the low mark, high mark, or something else?). When I refill the system I'm going to fill the tank up to the high mark, but unless I know whether the overflow should be included in the capacity or not I can't tell how much water was left in the system from the flush (if I put in 6 quarts is that 6 out of 6.9, or 6 out of 7.9, assuming the overflow tank is 1 quart?). Without knowing how much water is left in the system I can't get a 50/50 mix right.

So, back to the original question, does the overflow tank count as part of the coolant capacity or not?

Thanks again!
 
Messages
1,773
I appreciate the responses, but they're starting to get away from my original question. I'm really just trying to figure out whether the coolant capacity listed in the manual includes the overflow tank or not (and, I guess, would that mean the low mark, high mark, or something else?). When I refill the system I'm going to fill the tank up to the high mark, but unless I know whether the overflow should be included in the capacity or not I can't tell how much water was left in the system from the flush (if I put in 6 quarts is that 6 out of 6.9, or 6 out of 7.9, assuming the overflow tank is 1 quart?). Without knowing how much water is left in the system I can't get a 50/50 mix right.

So, back to the original question, does the overflow tank count as part of the coolant capacity or not?

Thanks again!

I thought all the responses were 100% on topic regarding your question. As Trav said, if the cooling system has an expansion tank then that it probably included in the total capacity. If it’s an overflow tank then it might not be included. Good luck.
 
Messages
4,974
I appreciate the responses, but they're starting to get away from my original question. I'm really just trying to figure out whether the coolant capacity listed in the manual includes the overflow tank or not (and, I guess, would that mean the low mark, high mark, or something else?). When I refill the system I'm going to fill the tank up to the high mark, but unless I know whether the overflow should be included in the capacity or not I can't tell how much water was left in the system from the flush (if I put in 6 quarts is that 6 out of 6.9, or 6 out of 7.9, assuming the overflow tank is 1 quart?). Without knowing how much water is left in the system I can't get a 50/50 mix right.

So, back to the original question, does the overflow tank count as part of the coolant capacity or not?

Thanks again!

I don't think you can get a definitive answer on this unless you could get in contact with the technical writer at the auto mfr who wrote the specs.

But the nice thing is a coolant mix does not HAVE to be a perfect 50:50, and in some climates the ratio can be up to 70:30 if needed.

Example for Hyundai:

page.h86.jpg
 
Messages
382
Location
New Jersey
I appreciate the responses, but they're starting to get away from my original question. I'm really just trying to figure out whether the coolant capacity listed in the manual includes the overflow tank or not (and, I guess, would that mean the low mark, high mark, or something else?). When I refill the system I'm going to fill the tank up to the high mark, but unless I know whether the overflow should be included in the capacity or not I can't tell how much water was left in the system from the flush (if I put in 6 quarts is that 6 out of 6.9, or 6 out of 7.9, assuming the overflow tank is 1 quart?). Without knowing how much water is left in the system I can't get a 50/50 mix right.

So, back to the original question, does the overflow tank count as part of the coolant capacity or not?

Thanks again!

Drain it, flush it fill it.
Test with a hydrometer.
Caveman comes to mind.
 

ssalvat

Thread starter
Messages
11
Ah, thank you for the clarification stower17, I wasn't picking up on the difference between overflow and expansion tanks. In this case the manual calls it a "reservoir" and says to fill it up to the "Full" mark, so pretty confident this would be considered an overflow and not expansion tank.

Fun side note, the owner's manual calls for Dexcool, the service manual calls for GM yellow "universal", and since it's really a Toyota everyone says it came from the factory with Toyota SLLC. Seems like any of them should be OK as long as I get all the old stuff out. Not sure I really want to open this can of worms....
 

ssalvat

Thread starter
Messages
11
I wouldn't be surprised at all if it was never changed. I bought it used with 98,000 miles on it and first call for a change is at 150,000 (it's currently at 140,000 or so). When I take off the radiator cap it looks orange, like Dexcool would, although there's a bit of pink crust around the overflow tank cap like it's Toyota SLLC. I can't see all the way down into the overflow because of the way the reservoir is shaped, kind of like there's an S in the tube that the coolant has to flow through, so couldn't say for sure. I guess I'll find out when I open the drain cock :)
 
Messages
60
I wouldn't be surprised at all if it was never changed. I bought it used with 98,000 miles on it and first call for a change is at 150,000 (it's currently at 140,000 or so). When I take off the radiator cap it looks orange, like Dexcool would, although there's a bit of pink crust around the overflow tank cap like it's Toyota SLLC. I can't see all the way down into the overflow because of the way the reservoir is shaped, kind of like there's an S in the tube that the coolant has to flow through, so couldn't say for sure. I guess I'll find out when I open the drain cock :)
Don't crank the drain cock like you're a superhero! Ask me why! I spent $20 on a cheap refractometer from Amazon to test my coolant concentration after a flush. I thought I had it dead-on 50/50 but I had it at 60% coolant. Definitely swap it out because most coolants have a time replacement as well. For my car, it was six years for the initial change, and then three years thereafter.
 
Messages
1,773
Typically an expansion tank has a pressurized cap and an overflow tank has a non pressurized cap. A system that uses an expansion tank shouldn’t have a cap on the radiator. A system that uses an overflow tank will 99% of the time have a radiator cap, the other 1% of the time it can be located somewhere else.

The owners manual calls it a reservoir because that’s exactly what it is, it holds liquid. And that’s all the vehicle operator really needs to know. If memory serves me correctly I think a 2008 Pontiac Vibe has an overflow tank, there should be a radiator cap on the radiator.
 
Messages
524
Location
Long Island, N.Y.
Hi All,

I'm going to be doing a coolant flush on my 2008 Pontiac Vibe. My plan is to drain as much coolant as I can from the radiator, block, and heater core, then fill up with distilled water 2-3 times until it comes out clean, then refill with coolant. I plan to measure how much coolant I get out at first (I assume it won't be 100%) to give me some idea how much water will be left in the system after the last flush so I can get the ratio right with concentrate. The manual says the coolant capacity is 6.9 quarts. My question is, does this include the fluid that's in the overflow tank, or just in the radiator/block/core?

Thanks in advance!
For the 06 Corolla in my sig, I usually buy One gallon of Toyota Red concentrate and mix it with another gallon of distilled water getting me 2 gallons of coolant. When all is said and done, I usually have a little less than half of the second mixed gallon left over. That includes draining , cleaning and refilling the reservoir. So 6.9 including the reservoir sounds right!

And that coolant should be Red or Pink (backwards compatible), not Yellow /orange......Definitely change it!
 
Messages
108
Location
Minnesota
Little off topic, but when I did the 2003 Vibe, took off the lower radiator hose and took out the thermostat and flushed them separately, radiator half self explanatory. I Confess to having used the garden hose and tap water, but it was always flushed with a mix-with-any coolant before adding the final pink coolant. I first intended to use distilled water, but once I took things apart it was obvious how to proceed.

The motor half I took off the upper heater core hose and flushed through that, then blew through it to clear the water, then funnel filled that hose with mix-with-any coolant till it ran out the thermostat, then blew that fluid out, and replaced with premixed Valvoline Toyota pink, Just a suggestion, stick with your plan if this isn't clear.

I think the little studs for the thermostat nuts are 8mm in a torx external socket, one of mine was in bad rusted condition, just be aware to check yours before removing the nut.

As for volume, when I did 2010 Sienna, 3.5 v6 and a rear heater core for passenger compartment, I used Rhino Ramps and backed it up when draining; pulled forward when filling, using the steepest part of the driveway, worked great. Can't remember this detail, I may have used the air bleeder on the top of the motor, when filling it. Worked great, may have had a little to add after it cooled down, but it was just to the overfill, there was never any big air belch after that. Again stick with your plan if this isn't clear.
 

ssalvat

Thread starter
Messages
11
stower17, the pressurized cap is definitely on the radiator, the reservoir cap is non-pressurized. I also have a 2006 Yukon XL that has the pressurized cap on the expansion tank, confused the hell out of me the first time I saw it and couldn't find the radiator cap :)

incognito_2u, thanks for the measurements. I'm going to try to measure the capacity of the reservoir tank separately from the rest of the vehicle and see what makes sense. If nothing else, I just realized that coolant testers are insanely cheap, I'm going to buy a couple, test on a known sample, and verify that I have a good mix in once I'm done.

Supersonic, I'm also planning to change out the thermostat, so definitely appreciate the tips. I actually did this on a 2011 Toyota Sienna and also used the air bleeder, but I don't think the Vibe has one, so I'll just have to burp it the old fashioned way.
 
Messages
60
stower17, the pressurized cap is definitely on the radiator, the reservoir cap is non-pressurized. I also have a 2006 Yukon XL that has the pressurized cap on the expansion tank, confused the hell out of me the first time I saw it and couldn't find the radiator cap :)

incognito_2u, thanks for the measurements. I'm going to try to measure the capacity of the reservoir tank separately from the rest of the vehicle and see what makes sense. If nothing else, I just realized that coolant testers are insanely cheap, I'm going to buy a couple, test on a known sample, and verify that I have a good mix in once I'm done.

Supersonic, I'm also planning to change out the thermostat, so definitely appreciate the tips. I actually did this on a 2011 Toyota Sienna and also used the air bleeder, but I don't think the Vibe has one, so I'll just have to burp it the old fashioned way.
The refractometer on Amazon tested perfectly in samples of distilled water, pure coolant, and 50/50.
 
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