Mazda Power Steering Fluid recomendation

Messages
11
Location
san diego
2012 Mazda 3 with the electro-hydraulic power steering system.

Looking for fluid recommendations. Manual recommends M5 or M3 fluid. Being a 2012, which might it have come with originally? I want as close to what is in there as is humanly possible.

I see Idemitsu sells a "type M- M3/M5" universal type fluid. I had horrible luck using their "PSF Universal Aisin" fluid in my '00 Toyota with all new OEM steering parts, so I am pretty reluctant to ever use that brand again. The same vehicle also rejected the "Lucas Power steering fluid with conditioners." At the end of the day, Genuine Toyota non-synthetic Dexron from the dealer worked perfectly. Since then, the whole "any ATF for the p/s in a non-Honda Japanese car" myth is pretty much a non-starter for me and I don't believe anything but the dealer stuff works as intended. Issue here is both M3 and M5 are listed in the manual, and I don't want to use the non-original type. Dealer stocks both M3 for $7 and M5 for $9. Is one synthetic and one non? I'd prefer non-synthetic as I'm confident it will cause leaks.

In the past, I prefer to replace ALL p/s hoses whenever changing fluid, as when any new fluid was added the original hoses would begin to "sweat" fluid within a few weeks. In this case I am only changing the high pressure line, so want something that is compatible enough that it will not cause return hoses to sweat fluid as happened in the past.

Last resort is try to save as much as the original fluid as possible, and then go to the junkyard to salvage as much original fluid as possible from as similar year Mazda.

I've just had terrible luck in the past when changing p/s fluid, I don't want any issues, cost is not an issue.
 
Messages
15,069
Location
Santa Barbara, CA
I would have come with M5 fluid which is not Mercon V. That being said, Mazda uses that for the same reason Ford uses Mercon V and LV for power steering fluid, they already have tons and it works. I would think you would be fine with either M5 or any ATF that meets or claims to meet the spec.
 
Messages
11,209
Location
USA
Power steering fluid doesn't normally have to be changed :unsure:

On page 10-2 (or 508) of the 2012 Mazda 3 owner's manual, it says
Mazda said:
Mazda Genuine ATF M-III, M-V, or equivalent (e.g. Dexron® II)

Any modern ATF will be acceptable. It probably came with M-V/M5 from the factory. Most Lucas Oil products are garbage.

Honda is the only non-Euro car that requires special power steering fluid.
 
Last edited:
Messages
9,124
Location
Virginia
Power steering fluid doesn't normally have to be changed :unsure:

On page 10-2 (or 508) of the 2012 Mazda 3 owner's manual, it says


Any modern ATF will be acceptable. It probably came with M-V/M5 from the factory. Most Lucas Oil products are garbage.

Honda is the only non-Euro car that requires special power steering fluid.


Power steering fluid definitely needs to be changed... It gets hot... Real, real hot and it oxidizes. Fluid degradation from heat does happen.

My power steering fluid was black when I first started pulling that fluid out.... Now it's red and looks way, way, way better.

I'd bet darn good money that the 98 Camry my lady has would have not had a power steering rack failure, power steering pump ... If I had changed that fluid out when we first got that car. $1,000 worth of work done to that power steering system.
 
Messages
70
Location
Cologne, MN
Go for it.
At about 60,000 miles on both of our Mazdas, I started paying attention to these things.
I examined the factory fill power steering and it was black and stinky (not the same scent as fresh ATF... which is also gut-wrenchingly stinky).
The Mazda 6 I was able to siphon and refill and get it good and fresh.
The Mazda 5 has the odd power steering with the tiny little reservoir that couldn't usefully be siphoned. I had the dealership do it. I think this is the same system as you are describing.

EDIT: And for the Mazda 6, I am using Amsoil SS (red bottle) as it is readily available. The Mazda 5 still has the MV.
 
Last edited:
Messages
5,905
Location
DFW
To get the fluid out you would need to remove the plastic underbody cover and disconnect one of the hoses from the bottom of the electric pump.
 

timoboy

Thread starter
Messages
11
Location
san diego
I agree with those that say leave it alone. This is a hydro-electric system that doesn't generate the heat of traditional systems where the pump spins in relation to engine speed regardless of need. My other Mazda with this system (2006 Mazda5 5MT) is still on the original fluid, albeit only 70k miles, but it still smells/looks perfect.

Unfortunately, the high pressure hose is leaking fluid and must be replaced.
 
Messages
5,905
Location
DFW
I agree with those that say leave it alone. This is a hydro-electric system that doesn't generate the heat of traditional systems where the pump spins in relation to engine speed regardless of need. My other Mazda with this system (2006 Mazda5 5MT) is still on the original fluid, albeit only 70k miles, but it still smells/looks perfect.

Unfortunately, the high pressure hose is leaking fluid and must be replaced.
I wanted to add that myself. I've noticed that the fluid doesn't quite have the stink I recall from my previous belt driven systems. I have 117,000 miles on the original fluid. I did snake the skinny vinyl hose from my MightyVac as far down as I could get it. I replaced no more than a few ounces of fluid, though. The replacement fluid I keep on hand is Mobil 1 universal synthetic ATF.
 
Messages
9,124
Location
Virginia
I agree with those that say leave it alone. This is a hydro-electric system that doesn't generate the heat of traditional systems where the pump spins in relation to engine speed regardless of need. My other Mazda with this system (2006 Mazda5 5MT) is still on the original fluid, albeit only 70k miles, but it still smells/looks perfect.

Unfortunately, the high pressure hose is leaking fluid and must be replaced.


Question is why is the hose leaking??

Blunt force impact ?

Bad rubber or sealant?

Or a distant possiblity.... The fluid had something to do with the leak happening.
 
Messages
11,209
Location
USA
Power steering fluid definitely needs to be changed... It gets hot... Real, real hot and it oxidizes. Fluid degradation from heat does happen.

My power steering fluid was black when I first started pulling that fluid out.... Now it's red and looks way, way, way better.

I'd bet darn good money that the 98 Camry my lady has would have not had a power steering rack failure, power steering pump ... If I had changed that fluid out when we first got that car. $1,000 worth of work done to that power steering system.

So in that case, you want something synthetic that could better cope with the heat and oxidation. The factory fill PS was most likely M5 and not synthetic. Therefore, Maxlife will be an improvement over what is in there now :)
 
Messages
1,503
Location
FL
I've used Castrol Import Multi-vehicle and Valvoline import multi-vehicle ATF in the electo-hydraullic system in my Mazda3, same is in the transmission.

I don't know why you are changing the P/S lines on a 2012... mine is a 2007 and has original, no leaks.
 
Messages
9,124
Location
Virginia
So in that case, you want something synthetic that could better cope with the heat and oxidation. The factory fill PS was most likely M5 and not synthetic. Therefore, Maxlife will be an improvement over what is in there now :)


I put synthetic in there... :)

Dexron VI... In my 08 Nissan Altima VQ.

Lady's 98 Camry got Dexron III.
 
Top