There is no service interval listed for changing the power steering (PS) fluid in the FSM. Apparently Mazda feels that the factory fill, with perhaps occasional top-ups, is good for the life of the car. That's unconscionable, IMO. Although operating conditions in an A/T are much more severe than those in a PS system, even in the latter the ATF fluid will turn black and degrade over time. Furthermore, there's no easy way to drain the fluid (no drain plug, for example) other than perhaps going under the vehicle and disconnecting a line. Additionally, if enough fluid is drained from the sysytem it will become air bound and must be bled. Not that air bleeding is difficult to accomplish, simply that it's another step that would have to be carried out.
I therefore tried to developed an alternate way to change the PS fluid that allowed me to remain up top, stay clean, and avoid the necessity to bleed the system.
The FSM specifies ATF M-III or equivalent (e.g. Dexron III) as the correct replacement fluid. Do not use power steering fluid in the Mazda PS system as it may cause damage. The capacity is 1.1 US quarts (1.0 Liter).
I chose Red Line D4 ATF as the correct 100% synthetic replacement fluid. Like all Red Line products it is ester based. Printed on the label is the following statement, "Red Line D4 ATF can be used in power steering units which require Dexron III, Dexron II or Mercon fluids ...".
Materials
Measuring Cup: mine is a Pyrex with a capacity of 16 oz (500 ml) with graduations in both ounces and milliliters.
Syringe: the type used to add distilled water to a battery (US $7 at Strauss Auto).
Red Line D4 ATF: 2 quarts (2 x .946 liters) @ US $9.95 + .70 state theft/quart for a total of US $21.30 at my local speed shop.
Proceedure
After a run with the PS fluid well-circulated, shut off the engine, remove the PS reservoir cap and then remove the strainer/filter by inserting a finger into it and gently pulling upward. Putting it aside in a safe, secure place, locate the Pyrex measuring cup against the shock tower so it's conveniently close to the reservoir.
Squeeze the bulb of the syringe and insert its tube into the reservoir, withdraw some fluid and empty it into the Pyrex cup. Repeat until 8 oz (250 ml) has been collected. This constitutes about 1/4 of the total fluid in the system yet still leaves enough in place so that air cannot enter. I couldn't judge the condition of the the fluid looking into the reservoir but the removed fluid in the Pyrex was completely black.
Insert a funnel into the reservoir and add new ATF until it reaches the max line on the reservoir. Then, remove the funnel, replace the strainer and reservoir cap, remove the Pyrex from the engine compartment, and close the hood. The system now contains ~ 25% new fluid.
The next step is to drive the car a sufficient distance that the new and old PS fluid will completely mix together and disperse throughout the system (I drove about 10 miles which I'm sure was more than enough). The synthetic fluid is completely compatible with the petroleum based one and they will readily intermix.
Now, carry out the above proceedure three more times.
At the second fluid removal from the 25% new/75% old mixture, the collected liquid in the Pyrex was less dark and actually had some hints of pink shot throughout. At the third fluid removal from the 50% new/50% old mixture, the collected liquid in the Pyrex definitely appeared toward the pink side and looked fairly clean. At the fourth fluid removal from the 75% new/25% old mixture, the collected liquid was quite pink and looked clean, almost as if it were new.
After the fourth and final fluid removal, replenish it with new ATF up to the max line. The PS system should now consist mainly of 100% new synthetic fluid so I assume this process essentially accomplished my goal of complete fluid replacement. This completes the job.
On the third refill, the D4 ATF container started to feel quite light, and considering that the total system capacity is a little more than one quart, I thought I might not have enough fluid to complete the fourth and final refill. Consequently, I drove out to the speed shop again and bought another quart. It was fortunate that I bought the second quart as I would have been slightly under max on the final refill without it. However, that leaves me with a lot of extra fluid so I may just drive around for about a week and then carry out another two removal/refills just to use up most of the remainder, as well as providing some additional system flushing.
Driving Impressions
Not too many at this point. Before I replaced the fluid, my PS system was in good shape and didn't seem to have any problems of which I was aware. The steering wheel does seem to turn more smoothly now and perhaps with somewhat less resistance than before. The smooth response also indicates that the method of fluid replacement I used did not allow air to enter the system. With the synthetic fluid I would also expect that temperature extremes will have less of a negative impact on steering response. We shall see.
Happy Motoring!
I therefore tried to developed an alternate way to change the PS fluid that allowed me to remain up top, stay clean, and avoid the necessity to bleed the system.
The FSM specifies ATF M-III or equivalent (e.g. Dexron III) as the correct replacement fluid. Do not use power steering fluid in the Mazda PS system as it may cause damage. The capacity is 1.1 US quarts (1.0 Liter).
I chose Red Line D4 ATF as the correct 100% synthetic replacement fluid. Like all Red Line products it is ester based. Printed on the label is the following statement, "Red Line D4 ATF can be used in power steering units which require Dexron III, Dexron II or Mercon fluids ...".
Materials
Measuring Cup: mine is a Pyrex with a capacity of 16 oz (500 ml) with graduations in both ounces and milliliters.
Syringe: the type used to add distilled water to a battery (US $7 at Strauss Auto).
Red Line D4 ATF: 2 quarts (2 x .946 liters) @ US $9.95 + .70 state theft/quart for a total of US $21.30 at my local speed shop.
Proceedure
After a run with the PS fluid well-circulated, shut off the engine, remove the PS reservoir cap and then remove the strainer/filter by inserting a finger into it and gently pulling upward. Putting it aside in a safe, secure place, locate the Pyrex measuring cup against the shock tower so it's conveniently close to the reservoir.
Squeeze the bulb of the syringe and insert its tube into the reservoir, withdraw some fluid and empty it into the Pyrex cup. Repeat until 8 oz (250 ml) has been collected. This constitutes about 1/4 of the total fluid in the system yet still leaves enough in place so that air cannot enter. I couldn't judge the condition of the the fluid looking into the reservoir but the removed fluid in the Pyrex was completely black.
Insert a funnel into the reservoir and add new ATF until it reaches the max line on the reservoir. Then, remove the funnel, replace the strainer and reservoir cap, remove the Pyrex from the engine compartment, and close the hood. The system now contains ~ 25% new fluid.
The next step is to drive the car a sufficient distance that the new and old PS fluid will completely mix together and disperse throughout the system (I drove about 10 miles which I'm sure was more than enough). The synthetic fluid is completely compatible with the petroleum based one and they will readily intermix.
Now, carry out the above proceedure three more times.
At the second fluid removal from the 25% new/75% old mixture, the collected liquid in the Pyrex was less dark and actually had some hints of pink shot throughout. At the third fluid removal from the 50% new/50% old mixture, the collected liquid in the Pyrex definitely appeared toward the pink side and looked fairly clean. At the fourth fluid removal from the 75% new/25% old mixture, the collected liquid was quite pink and looked clean, almost as if it were new.
After the fourth and final fluid removal, replenish it with new ATF up to the max line. The PS system should now consist mainly of 100% new synthetic fluid so I assume this process essentially accomplished my goal of complete fluid replacement. This completes the job.
On the third refill, the D4 ATF container started to feel quite light, and considering that the total system capacity is a little more than one quart, I thought I might not have enough fluid to complete the fourth and final refill. Consequently, I drove out to the speed shop again and bought another quart. It was fortunate that I bought the second quart as I would have been slightly under max on the final refill without it. However, that leaves me with a lot of extra fluid so I may just drive around for about a week and then carry out another two removal/refills just to use up most of the remainder, as well as providing some additional system flushing.
Driving Impressions
Not too many at this point. Before I replaced the fluid, my PS system was in good shape and didn't seem to have any problems of which I was aware. The steering wheel does seem to turn more smoothly now and perhaps with somewhat less resistance than before. The smooth response also indicates that the method of fluid replacement I used did not allow air to enter the system. With the synthetic fluid I would also expect that temperature extremes will have less of a negative impact on steering response. We shall see.
Happy Motoring!
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