First Gen-Coolant quantity for drain and fill

Hi everyone,

I've been trying to find the amount of coolant needed to do a drain and fill on a 2012 3.7L CX-9. I plan on going to the dealer and buying FL22(It calls for it on the tank cap) and it's pricey. I believe the system takes 3.6 gallons in total, not sure how much i can actually drain.

Any links to "How to's" would be appreciated as well.

Thanks
 
V
2016 Mazda CX-5 GT
Just purchased 3 gallons of FL22 at the Mazda dealer for a whopping $25 each! Should be enough. Maybe I*ll take a crack at the flush this weekend...
 
I too purchased FL22 for $25 a gallon (55%45% prediluted) and was planning on doing this this weekend. Luckily, there was a mechanic at the parts desk and said I'd only need 2 gallons, which "would be better than nothing" but I believe would leave me with 1.2 gallons of old fluid. I'm still a little confused I think he said they would use 4 gallons for a proper flush, he explained it was a vacuum pump system. I was expecting the old school way of water and cleaner, dump and then new coolant. The price for the labor, coolant and kit at the dealer was $256. After watching videos and seeing the prevalence of the waterpump issue pop up I'm going to see if my local mechanic has the flushmachine and his price for a thermostat and flush. Updates to follow.
 
V
2016 Mazda CX-5 GT
Hmmm.. Please let me know!

I just flushed mine out today and refilled. According to the manual, the 2012 CX 9 takes about 3.0 gallons of FL22, which I purchased. I flushed 3 times, and only about half (1.5 gallons) came out the entire time.

Does this mean that 1.5 g of water I used to flush is still inside, so I*m now 1/4 diluted? This seems very odd to me and not good! Can*t be only CX 9 with this issue.
 
V
2010 CX-9 GT
Hmmm.. Please let me know!

I just flushed mine out today and refilled. According to the manual, the 2012 CX 9 takes about 3.0 gallons of FL22, which I purchased. I flushed 3 times, and only about half (1.5 gallons) came out the entire time.

Does this mean that 1.5 g of water I used to flush is still inside, so I*m now 1/4 diluted? This seems very odd to me and not good! Can*t be only CX 9 with this issue.
Yes, the coolant will not all come out of the radiator. This is a "feature" of the Ford/Mazda V6 design - search the internet and you will find a lot of pages discussing this. In order to get all the old coolant out you have to flush it several times with water. Prestone used to make a coolant flushing kit that spliced in a connector for a garden hose in one of the heater hoses. You would hook the hose up, turn it on, then start the car with the radiator drain open and run it until the water ran clear. This isn't the best idea for several reasons (tap water has minerals in it, and the flushing method spilled lots of diluted coolant all over the place).

If you really want all the old coolant out, I'd recommend draining the system as much as possible and then refilling with distilled water, and repeating this several times. Assuming you are only getting half the coolant out each time, you would need to do this about 5 times to get >95% of the old stuff out. Then I'd refill it with undiluted FL22 - assuming only half of the old coolant is coming out each time, this should put you right near a 50/50 mix. I'd use a coolant tester (hydrometer) to see what the concentration is after driving it a couple of times and top it off with coolant and/or water to fine tune the mixture.

You can get more of the old stuff out by disconnecting the lower/upper radiator hoses and blowing in compressed air to the upper hose. This still won't get everything. There are also ways to use a shop vac to suck out the old coolant - there are videos out there.
 
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V
2016 Mazda CX-5 GT
Uh oh, just thought of something. I used Prestone chemical flush with the old coolant, then drained and filled twice with distilled water, then added FL22. Now I*m paranoid that some of the chemical flush is still lurking in the system and will damage the already vulnerable water pump! Should I just do it all over again a few more times? Feel like an idiot!
 
V
2012 Mazda CX-9 Grand Touring FWD
Hmmm.. Please let me know!

I just flushed mine out today and refilled. According to the manual, the 2012 CX 9 takes about 3.0 gallons of FL22, which I purchased. I flushed 3 times, and only about half (1.5 gallons) came out the entire time.

Does this mean that 1.5 g of water I used to flush is still inside, so I*m now 1/4 diluted? This seems very odd to me and not good! Can*t be only CX 9 with this issue.
Yes, this is correct. This is why I always just drain and fill, especially with pre-diluted coolant. I just drain and fill more frequently than I would otherwise.
 
V
2016 Mazda CX-5 GT
Yeah, I*ll do that next time. Thanks. Just brought it to my local trusted mechanic and he did the flush (I brought him 3 gallons of FL22). All is well for now! Best medicine for preemptively keeping the dreaded water pump happy
 
To close the loop. I ended up going to my mechanic and asking for a flush and a new thermostat(120k miles). He said he'd wait until there was a problem with the Tstat and did the flush that required 3 gallons and cost a little less than $200. fingers crossed!
 
V
2016 Mazda CX-5 GT
Yup, I did exactly the same! I typically do all maintenance myself, but paying a few extra dollars for a real flush on a machine, and using genuine FL22 is much cheaper than having a water pump go out.
 
V
2010 CX-9 GT
Yup, I did exactly the same! I typically do all maintenance myself, but paying a few extra dollars for a real flush on a machine, and using genuine FL22 is much cheaper than having a water pump go out.
Not sure why you are under the impression that changing the coolant will delay the water pump failing. There is no evidence that changing the coolant delays water pump failure. If it did, Ford/Mazda would be telling everyone to change their coolant.
 
V
2016 Mazda CX-5 GT
Here is an article I read - * The coolant can become more acidic over time and lose its rust-inhibiting properties, causing corrosion. Corrosion can damage the radiator, water pump, thermostat, radiator cap, hoses and other parts of the cooling system, as well as to the vehicle heater system. And that can cause a car engine to overheat.*

Plus, I would t exactly put faith in Mazda / Ford being reactive. It would admit defeat and force a recall
 
V
2010 CX-9 GT
Here is an article I read - * The coolant can become more acidic over time and lose its rust-inhibiting properties, causing corrosion. Corrosion can damage the radiator, water pump, thermostat, radiator cap, hoses and other parts of the cooling system, as well as to the vehicle heater system. And that can cause a car engine to overheat.*

Plus, I would t exactly put faith in Mazda / Ford being reactive. It would admit defeat and force a recall
These things have been failing on relatively new vehciles with low miles (~60k thousand) while others have gone 150k+ with no issues. Corrosion doesn't seem to be a root cause.

It's a crap shoot. Changing the coolant can't hurt, but it's no guarantee.

I don't know if they'd be forced to recall anything. Recalls are only generated when the failure causes a safety issue. The engine loses power and trashes itself, but it doesn't seize up and fail violently.
 
V
92 MX-3; 18 CX-5
Agree with Jal142 that changing coolant does little to preserve the water pump - but it is good overall for the cooling system. 5 years or 100K drain and refill the radiator is more than good enough to protect the cooling system. Concerned that you are not replacing all the coolant? Then drain and refill 3x and you will have 90% new coolant. Just run the engine to operating temp (open thermostat) between each drain / refill cycle. From experience it is faster and easier as a DIY to drain and refill (no straight distilled water or flush chemicals or kits). If you flush the system and end up with all water then you need some concentrated coolant on hand to get back to the proper mix.
 

helbigtw

T-Rav
L
PA
V
08 CX-9 GT FWD
I agree that the impeller will not be affected by coolant change, but concerning the impeller bearing--high quality motor oil will better lubricate the outside of the bearing, and newer coolant might help the inside area on the other side of the bearing. Wouldn't you think?
 
V
92 MX-3; 18 CX-5
Not to discourage changing engine oil and coolant on a regular basis - but these do not extend the life of the water pump. The water pump shaft bearing is sealed with some lubrication inside. It does not use coolant or engine oil for lubrication - though both of these are in contact with the water pump on this engine.
Beyond lubrication oil does provide engine cooling along with the coolant. The life of the water pump bearing will be shorter if then engine runs hot or overheats due to lack of oil or coolant.
 

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