Which Fluid Flush is Most Important?

V
2013, Black CX-5 Grand Touring AWD 6 spd Automatic
Hi,

Just took my car in for a routine oil change/tire rotation and my dealership is recommending:

-Brake Fluid Flush (says its dirty)
-Coolant Flush (says its dirty and low)
-Rear Differential Fluid Flush

Which would be the most important? Should I do them all? I thought these fluids were lifetime fluids. Any idea on reasonable rates to do this?

Thanks All!
 

ColoradoDriver

Gen-1 Kodo Design
Contributor
V
2014 CX-5 Touring AWD
Hi,

Just took my car in for a routine oil change/tire rotation and my dealership is recommending:

-Brake Fluid Flush (says its dirty)
-Coolant Flush (says its dirty and low)
-Rear Differential Fluid Flush

Which would be the most important? Should I do them all?

Thanks All!
It looks like you have a 2013 AWD CX-5? Always refer to your maintenance schedules in the manual.

Coolant is good for 10 years or 120,000 miles. Replace it at either of those intervals. Otherwise, just top up as needed in the reservoir with FL-22 coolant. Although green, it is not the same as your standard "green" coolant. Also, (IMPORTANT: When the car is completely cool!) pop open the reservoir and coolant caps yourself and inspect the fluid. Should be dark greenish in color for FL-22 fluid. If it still looks like that and doesn't appear dirty, then you are fine. If you have reached 120,000 miles, then yes, go ahead and replace the coolant. If it is genuinely dirty, then this would probably be my number 1 priority. But I'd check and make sure it actually is, otherwise you could be spending $ to replace it when it doesn't need it yet (I don't know what mileage you're at).



Brake fluid, I believe is as needed per the maintenance schedule. I don't really know how to check/tell myself. If you haven't replaced it in a few years, then probably doesn't hurt to do so.



As for the Rear Differential oil, the manual only specifies certain conditions to change it. Same for the transfer case oil. I just went ahead and had both replaced at around 50k miles. (Or maybe it was 60k? can't remember when I did it now). Some have remarked that these are filled low from the factory.



I thought these fluids were lifetime fluids.
The transmission fluid is the only fluid specified as "lifetime", but what constitutes "lifetime" is open to anyone's interpretation, and plenty of us have done drain/fill services for it. My advice, read your maintenance scheduled in the manual.
 
V
2013, Black CX-5 Grand Touring AWD 6 spd Automatic
Thank you.

Thanks! My 2013 CX-5 Grand Touring is at 150k already. I opted to do this Coolant and and EFI on the throttle body. Brake fluid will be my next task.

It looks like you have a 2013 AWD CX-5? Always refer to your maintenance schedules in the manual.

Coolant is good for 10 years or 120,000 miles. Replace it at either of those intervals. Otherwise, just top up as needed in the reservoir with FL-22 coolant. Although green, it is not the same as your standard "green" coolant. Also, (IMPORTANT: When the car is completely cool!) pop open the reservoir and coolant caps yourself and inspect the fluid. Should be dark greenish in color for FL-22 fluid. If it still looks like that and doesn't appear dirty, then you are fine. If you have reached 120,000 miles, then yes, go ahead and replace the coolant. If it is genuinely dirty, then this would probably be my number 1 priority. But I'd check and make sure it actually is, otherwise you could be spending $ to replace it when it doesn't need it yet (I don't know what mileage you're at).



Brake fluid, I believe is as needed per the maintenance schedule. I don't really know how to check/tell myself. If you haven't replaced it in a few years, then probably doesn't hurt to do so.



As for the Rear Differential oil, the manual only specifies certain conditions to change it. Same for the transfer case oil. I just went ahead and had both replaced at around 50k miles. (Or maybe it was 60k? can't remember when I did it now). Some have remarked that these are filled low from the factory.





The transmission fluid is the only fluid specified as "lifetime", but what constitutes "lifetime" is open to anyone's interpretation, and plenty of us have done drain/fill services for it. My advice, read your maintenance scheduled in the manual.
 

ColoradoDriver

Gen-1 Kodo Design
Contributor
V
2014 CX-5 Touring AWD
Thanks! My 2013 CX-5 Grand Touring is at 150k already. I opted to do this Coolant and and EFI on the throttle body. Brake fluid will be my next task.
Ah 150k, yes definitely get the coolant replaced! Brake fluid next if it's been a couple years.

As for the rear differential (and also the transfer case since AWD), I'd still get both of those replaced at some point.
 
V
'16.5 CX-5 Touring AWD
It looks like you have a 2013 AWD CX-5? Always refer to your maintenance schedules in the manual.

Coolant is good for 10 years or 120,000 miles. Replace it at either of those intervals. Otherwise, just top up as needed in the reservoir with FL-22 coolant. Although green, it is not the same as your standard "green" coolant. Also, (IMPORTANT: When the car is completely cool!) pop open the reservoir and coolant caps yourself and inspect the fluid. Should be dark greenish in color for FL-22 fluid. If it still looks like that and doesn't appear dirty, then you are fine. If you have reached 120,000 miles, then yes, go ahead and replace the coolant. If it is genuinely dirty, then this would probably be my number 1 priority. But I'd check and make sure it actually is, otherwise you could be spending $ to replace it when it doesn't need it yet (I don't know what mileage you're at).



Brake fluid, I believe is as needed per the maintenance schedule. I don't really know how to check/tell myself. If you haven't replaced it in a few years, then probably doesn't hurt to do so.



As for the Rear Differential oil, the manual only specifies certain conditions to change it. Same for the transfer case oil. I just went ahead and had both replaced at around 50k miles. (Or maybe it was 60k? can't remember when I did it now). Some have remarked that these are filled low from the factory.





The transmission fluid is the only fluid specified as "lifetime", but what constitutes "lifetime" is open to anyone's interpretation, and plenty of us have done drain/fill services for it. My advice, read your maintenance scheduled in the manual.
Great write up, Colorado. It's awesome having members like you on this board.

Only thing I would add to this is about the brake fluid being serviced. While most manufacturers leave brake fluid to be "inspect only" in an owner's manual, it is not a bad idea to do a brake bleed every time you get the rotors & pads replaced. Yes it's true that there are millions of cars out there that have never changed their brake fluid, however, just because this is the case doesn't mean it's the best practice for a braking system. Just my 2 cents.
 

erhayes

Contributor
V
Mazda CX-5 FWD Touring
I get the brake fluid changed when the brake pads are serviced. I have never seen in a MAZDA manual that any fluids are labeled "LIFETIME" People are doing MAZDA a disservice stating this in my opinion. Ed
 
V
2016.5 CX-5 GT AWD titanium/black 2016 Miata Club ST MT white
Good advice by all here.

The rear diff isn't a 'flush', it's just a drain and fill.
 

Kaps

Contributor
V
CX-5 Touring 2016.5
My CX-5 has 27K miles and is a 16. I hope to keep it till 120-150K miles and only thing other than regular oil changes every 7-8K miles till 60K miles then every 10K miles (Mobil 1 / Mazda Moly) will be
Tx fluid drain and (fill and drain twice)
Brake Pads twice (or once)
Rotors (Hopefully once)
Coolant (once)
Brake Fluid flush Once
Filters etc.
Intake Valves (hopefully never or once)

Thoughts?
I hated my past cars but they were as close to fill it and forget it as you can get. Am I asking too much from my CX5?
P.S. on my 2nd car which is a Camry - half of the above would be never done.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
Hi,

Just took my car in for a routine oil change/tire rotation and my dealership is recommending:

-Brake Fluid Flush (says its dirty)
-Coolant Flush (says its dirty and low)
-Rear Differential Fluid Flush

Which would be the most important? Should I do them all? I thought these fluids were lifetime fluids. Any idea on reasonable rates to do this?

Thanks All!
Like ColoradoDriver said, when you drain and fill rear differential gear lubricant, you also need to change the same oil in front transfer case for AWD CX-5. Your 2013 CX-5 has 150,000 miles and this service should be done long ago although the manual specifies no service interval but change them only under certain circumstances. Especially it has been verified many times that the rear differential gear lub level is always too low from factory.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
Brake fluid should be changed every 2 years.
Strangely Mazda, and all other car manufactures as far as I know, do not specify brake fluid replacement in maintenance schedule for US market, although they all, including Mazda, include such service interval, normally it's 2 years like you said, on brake fluid replacement for all other regions, such as Australia, in the world.

We all say we should follow manufacture recommended maintenance schedule. But we can't blame car owners who only follow recommended maintenance schedule, can we? ;)(wink)
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
Great write up, Colorado. It's awesome having members like you on this board.

Only thing I would add to this is about the brake fluid being serviced. While most manufacturers leave brake fluid to be "inspect only" in an owner's manual, it is not a bad idea to do a brake bleed every time you get the rotors & pads replaced. Yes it's true that there are millions of cars out there that have never changed their brake fluid, however, just because this is the case doesn't mean it's the best practice for a braking system. Just my 2 cents.
Since car manufactures never specify replacement interval for brake fluid in the US, we can simply get this brake fluid tester (less than $2 from China!) to verify if the brake fluid really needs to be replaced.

Unobtanium's dealer tested his previous 2015 CX-5 at ~100,000 miles and told him his brake fluid needs replacement as the fluid contains 2% of moisture. My 185,000-mile 1998 Honda CR-V was having factory Japanese brake fluid for over 20 years until recent brake pads and shoes replacement, but the fluid flushed out still looked clear, and I have never had any brake fluid related issues before the fluid replacement. (knock on wood)



Brake Fluid Tester.jpg
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg. Plano, TX
Contributor
My CX-5 has 27K miles and is a 16. I hope to keep it till 120-150K miles and only thing other than regular oil changes every 7-8K miles till 60K miles then every 10K miles (Mobil 1 / Mazda Moly) will be
Tx fluid drain and (fill and drain twice)
Brake Pads twice (or once)
Rotors (Hopefully once)
Coolant (once)
Brake Fluid flush Once
Filters etc.
Intake Valves (hopefully never or once)

Thoughts?
I hated my past cars but they were as close to fill it and forget it as you can get. Am I asking too much from my CX5?
P.S. on my 2nd car which is a Camry - half of the above would be never done.
Yes, many friends and family who keep getting Toyota Camry mostly because it's not only very reliable, but also it needs very minimum maintenance. Mazda on the other hand requires more frequent maintenance, and still is not as reliable as Toyota in general. For example, Toyota has 10,000-mile oil change interval but Mazda uses 7,500-mile OCI.

I'd following Flexible OCI to change oil if you really want to stretch the oil change interval. Although I'd not changer oil past 7,500 miles but for your 2016 CX-5 Flexible does have 12-month or 10,000-mile maximum interval you prefer.

And you can save the cost of new rotors by simply re-surface them with new pads. And here in Texas if you don't DIY, Brake Plus, at least the one in Plano, is a great place to do the job.
 

Kaps

Contributor
V
CX-5 Touring 2016.5
Yes, many friends and family who keep getting Toyota Camry mostly because it's not only very reliable, but also it needs very minimum maintenance. Mazda on the other hand requires more frequent maintenance, and still is not as reliable as Toyota in general. For example, Toyota has 10,000-mile oil change interval but Mazda uses 7,500-mile OCI.

I'd following Flexible OCI to change oil if you really want to stretch the oil change interval. Although I'd not changer oil past 7,500 miles but for your 2016 CX-5 Flexible does have 12-month or 10,000-mile maximum interval you prefer.

And you can save the cost of new rotors by simply re-surface them with new pads. And here in Texas if you don't DIY, Brake Plus, at least the one in Plano, is a great place to do the job.
I will keep it at 7500 or 8000 miles then. My next Mazda OC will be at my Toyota dealer with Sam's Club bought Mobil 1.
 
V
CX-5 AWD GT
Since car manufactures never specify replacement interval for brake fluid in the US, we can simply get this brake fluid tester (less than $2 from China!) to verify if the brake fluid really needs to be replaced.

Unobtanium's dealer tested his previous 2015 CX-5 at ~100,000 miles and told him his brake fluid needs replacement as the fluid contains 2% of moisture. My 185,000-mile 1998 Honda CR-V was having factory Japanese brake fluid for over 20 years until recent brake pads and shoes replacement, but the fluid flushed out still looked clear, and I have never had any brake fluid related issues before the fluid replacement. (knock on wood)



View attachment 220806
That brake fluid tester is a joke. Ive used it several times on a brand new unopened bottle and it was giving me a false positive for moisture. Ive thrown it in the bin. The only true tester is a boiling point tester. Just stick to a 2yr interval and youll be alright. I work as a mechanic and thats what I do.
 

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