How often is prudent to change the following fluids?

ATF
AWD transfer
Differentials
Coolant
Brake
Power Steering


Right now, I have about 30k/3 years on all of the above. I just bought a few bottles of DOT 5.1 brake fluid to exchange and I have another gallon and a half of coolant from when I changed it last time so I'll do both at the same time this coming week. I'm curious if it would be wise to do the ATF, transfer, and diffs around the same time. For power steering, I've refreshed it a few times with DEX III/MERCON ATF over the years so it should be good for a while and still is bright red.

Also, do Infiniti dealers do an ATF drain and fill or use a flush device? I've had them do the diffs, transfer case, and transmission 3 years ago.

I do 30k for all of those.

Ilya has got excellent suggestion - keep it running tip top. I do very close to that , brake flush & bleed bi-yearly for all my vehicles. You'll feel the difference in brake "confidence" and immediate brick under foot feel.
Next is ATF really wakes-up the transmission , and to a lesser extent even ps fluid flush you still get a very noticeable road feel , especially with the variable rate systems. PS reservoir can be emptied ala turkey baster then refilled for approximately 1/3 exchange OR running an extension to return hose into bucket, with rsvr. plugged, and swinging lock-to-lock under key-starter drive (ECM fuse removed).That'll get almost 100% exchange!
All the rest good maintenance practices , your car loves - but much less noticed , but that's a basis for longevity for sure.

I couldn't agree more. The fluids in your car are its life blood. Glad to see power steering and brake fluid were mentioned. Some might overlook those. Macgiver described the best, easiest way to change PS fluid. I used to use the lovely misses turkey baster too, but it was decided (by her) I should buy siphon pump ($20). I put one tube in the reservoir and the other tube into a 2 liter soda bottle - then screw the cap back on the bottle when done. You can buy actual Nissan fluids on Amazon or Ebay. In fact there are a couple actual Infiniti dealers on Ebay who sell fluids at a much lower cost than your local dealer. Shipping is usually free too.
I use only Nissan / Infiniti fluids (aside from Mobil 1). I am sure there are less expensive brands that claim to be 'the same' and that might be perfectly fine. But it's an expense every 3 years so paying a little extra is not a big deal and overkill never killed any car. My car has 108,000 miles, and is nearly 11 years old. It doesn't lose oil between changes, has no issues mechanically, and drives and performs like the day I bought it.

ArmedAviator wrote: ↑

Sun May 19, 2019 8:49 am

Also, do Infiniti dealers do an ATF drain and fill or use a flush device? I've had them do the diffs, transfer case, and transmission 3 years ago.

I believe so. I think the official procedure for the 7speed is to run through different gears and such, which is why it cost so much. I got mine done at a nissan dealer to save $100.

ArmedAviator wrote: ↑

Sun May 19, 2019 8:49 am

...Also, do Infiniti dealers do an ATF drain and fill or use a flush device? I've had them do the diffs, transfer case, and transmission 3 years ago.

For the 7AT, the FSM calls for drain and fill, not flush. My dealership does it this way. I had mine done at around 60k, when the oil jet/timing chain recall work was done...probably due again soon.

If that's the case then I may be confusing the M with my CVT Quest. Although I would swear when I got the M trans fluid replaced, they would hook it up to the machine/pump and have the car on while running the fluid in/out until it reached a certain temp.....

Also...are you referring to the FSM or the maintenance booklet? The maintenance booklet does not recommend changing the AT fluid at all.
What's up with that????

I do 50k on all (myself) except ATF which i did at 60k at the dealer for a good enough price it wasn't worth messing with myself. The ATF is the only not listed in the manual which was 60k on all the 5at's and I was going to do 50k since the 7at obviously shifts more and possibly is harder on the fluid, but I think I put it off and just ended up on the old schedule Factory coolant is good for 100k, and after that i'll do 50k, brake fluid is 25k or 3 years or if it just looks too dark.

A good reason to do coolant more often than the schedule suggests is if the water pump is expensive, in a tight spot (many shop hours) , OR one of the timing chain-driven ones inside the timing cover($$$$worst).
How about ALL of the above
"Fresh" coolant is VERY good to water pumps and alloy fittings , radiators , what-have-you.

p.s. just changed diff & transfer case oil in AWD 1st time , 51k mi. Diff fluid appeared pretty good as expected , transfer fluid very dirty and looked USED and really needed it

What oil should be used for the diffs (AWD)? Any GL-5? What weight? How much will I need for both diffs?

How much Matic-S ATF is needed to do the transfer case?


I'm going to knock out oil and coolant today. I've used the Nissan blue pre-mixed coolant 3 years ago and still looks perfect but it's a nice day to knock out a few things. I have DOT 5.1 fluid waiting to be bled through the system, but I'm waiting for some lime green caliper paint to show up so I can get two birds stoned at once.

I didn't change my coolant yesterday, but I did to a whole lot more.

I changed diff fluid both front and back with 75W-90 Valvoline. The back took just shy of 2 quarts and the front took about 3/4 of a quart. Went smoothly and reused the old washers, but tightened down a bit extra since the washers were already tightened once before. Front was a PITA only because I cant get the plastic cover off due to rusted bolts just spinning the fasteners on the backside of plastic. Old fkuid had 3 years/30k miles on it. Front was as clean as new. Rear was slightly dirtier with 3 years/30k miles but still had plenty of life left. I'm going to use 60k/6 year change intervals for the diffs from now on.

I also flushed my system with Motul DOT 5.1 brake fluid. Old fluid was slightly more yellowed than the new fluid with 3 years on the clock. I also took this time to clean and lube my brakes for the first time in 3 years since I installed them. These StopTech pads are dusty as all hell and tear up rotors but damn do they stop and with no noise! The rears are over halfway worn, and the inside pads worn more than the outside pads.....what would cause this on both calipers? One rear caliper had a seized pin which affected wear pattern on pads. I did not change any pads, just lubed.

I bought a new radiator cap for the coolant change I shall do next week.

Best you can do is lube those slides/surfaces well and with proper grease .I used to set up (Tradeshow Electric) SEMA Las Vegas ,and attending got to meet/ speak to many varied peoples. And a brake consultant explained the pad wear will be , after initial install -lubed up, tilted to more one side - THEN as age , lube erosion etc.gives a reversal where the other side is slated to wear more and intention is to have a sort of equilibrium at the End Of LIfe juncture of your brakes. We all see , usually , either inboard or outboard is consistantly worn more and we see this different all over the map with different cars.Not going into ALL the details of factors - for example ONE is that the square-edged rubber piston seal ( NOT dust seal that you can see) will PULL & back off the piston upon releasing brakes , yeah OK , so you see a very tricky & subtle set of engineering features the engineers try to have to achieve a CONTINUED & fairly even pad wear ? NEVER COMPLETELY EVEN
"Today's" designs are waaay better than most of the like in 70's, 80's .Basically , myself, I like the slide-action as gotten way better, and tending to last longer , keeping smooth "action" more throughout pad life.

I'm a Amsoil snob

Their website gives weights, amounts etc.

I love their stuff, NO AFFILIATION, car runs like a dream after replacing it and I'm very interested.

Andy

I'll replace my rotors anx pads again next year, possibly see about upgrading to the Sport package calipers at the same time for bigger brakes. Does anyone know off hand if I would need different brake hoses for the sport calipers?

Anyway, regarding Amsoil, I've used their stuff before. 15 years ago they were far exceeding what was available. Now, I'm very satisfied with my Pennzoil Platinum /Ultra Platinum PurePlus and may switch Amazon Basics based on "unscientific studies" on ProjectFarm's youtube channel. I've taken my Pennzoil to 7,000 miles no problem. I have figured a 2x a year change is best....spring and fall when the temps are nice to be outside and I end up anywhere between 5-6k miles on the oil.

I set up an appointment for the trans and trabsfer case fluids on Tuesday. I'm going to pick up a spare gallon of coolant while I'm there and then change my coolant.

When you say taken to 7k no problem, do you mean with good used oil analysis results or just that the engine didn't seize? People always say they like this or that oil but never get the analysis done so its really just a guessing game.

With the sport brakes you will need new hoses, there are parts lists floating around that not too difficult to put together but you'll need sport wheels or maybe spacers if you have the standard M 18" wheels. Are you doing for looks or stopping power because with good summer tires you can get some Hawk street/race pads, EBC yellow or blue stuff, even Hawk HPS/street 5.0 should be able to trigger ABS with good tires.

I almost did a UOA last year. I decided it's not worth my time. I'm confident the Pennzoil Platinum is up to the task. And ProjectFarm's recent, unscientific oil competition on Youtube confirmed what I suspected. This is basically the next best oil behind Amsoil.

I have a 2012 M37x. It now has 87,000 miles on it. I have never changed any fluid other than oil.

I have test strips for coolant and brake fluid. I tested these fluids today. Coolant protection is at -34 deg F with a boiling point of 265 deg F. pH is at 7. Brake fluid corrosion level is at 10 ppm. No need to replace either. I think that the manufacturer recommends periodic brake fluid changes that I have no performed on the advice of the Infiniti dealer, who told me that it isn’t necessary - so I have chosen to monitor the fluid condition and see what happens, rather than follow the manufacturer’s recommendation.

I have never done anything more than follow the manufacturer’s recommendations on fluid changes. (One exception: I had a BMW e39 that used Dextron in the tranny and BMW said that it was “lifetime”. Nuts to that. At 100K miles I chickened out on the lifetime claim and began dropping the fluid every 30,000 miles. I sold the car to a friend. It now has 310,000 miles on it with no tranny problem.) I have owned cars for over 50 years. In over 50 years, I have never had any sort of brake fluid related problem or coolant related problem. I have never had any sort of engine problem related to oil. I have never had any sort of differential problem. I have had several tranny problems, none of which were attributed to a fluid problem - trannies are a pain, among the least reliable parts of the machine.

In my driving experience the engineers who designed my cars and made the fluid change recommendations have been right, always. I feel that it is a waste of time and money to pick arbitrary points at which to change fluids - not to mention the added use of the earth’s resources.

Bill K interesting take on fluids, i generally just follow the book as well but i realize some guys love to be in the garage .

I agree that it is an interesting take - not one I've seen verbalized before. I guess that I'm risk adverse enough that I tend to rely on what works, vs. testing an approach that may or may not work. I'm not sure if engineering writes the maintenance schedules or if someone in marketing/communications does it. In addition, we gets lots of conflicting guidance on whether something like transmission flushes or power steering flushes are necessary or not. I fall into the camp that treats some of these as insurance - a $300 transmission flush is a whole lot cheaper than buying a new transmission or rebuilding one that may fail again in 6 months.

Well, if the marketing/communications department is writing the service interval specifications they’re doing a great job. ;-) I haven’t had a fluids related failure in the 50+ years I’ve owned cars.

I’m not making an argument for monitoring fluid condition rather than replacing it. My argument is this: All will be well if we do nothing more than change fluids at the manufacturer’s recommended time/mileage - and it is generally a waste of time, money and the earth’s resources to set up one’s own arbitrary fluid change schedule.

As with all things, there are exceptions. In the case of my BMW e39 tranny fluid I made an exception because I was positive that Dextron III was never intended to be a lifetime fluid. As far as monitoring my Infiniti brake and coolant fluids, I was told by the Infiniti dealership (Bloomington, MN) that it isn’t necessary to change brake fluid at the Infiniti-recommended intervals. Because I follow the manufacturer’s schedule I had a problem with this advice and decided to check for myself. Since the brake fluid test strips have a coolant test at the other end of the strip I am doing both. So far I am finding that the dealer is right for brake fluid. I find this a bit surprising, actually. Normally I assume that, relative to fluid changes, the manufacturer’s interests and my interests are aligned - neither of us wants a failure due to fluids. OTOH I assume that the dealer’s interests are aligned with his $$$ interests and not my interests.

Thanks Bill - I had understood the recommendation for brake fluid change intervals has to do with the hygroscopic properties of the brake fluid (the ability to absorb moisture) having a limited life. Living the very damp area of Puget Sound, I often hear of premature brake component failure due to the loss of hygroscopic properties. Does your test measure that or am I just giving into marketing hype? I found an article that indicates that strips aren't useful for brake fluid: "Electronic testers and test strips are commercially available to measure moisture content, however moisture test strips were taken off the market because they absorb moisture in the air before they can be used."

The test strips that I am using are made by Phoenix Systems. Here they are:

https://www.amazon.com/gp/product/B0753 ... UTF8&psc=1

They are still being marketed.

Test strips are sealed, individually, in a foil wrapper. I’m not concerned about contamination, they are exceedingly well packaged.

These strips do not measure the moisture content in the brake fluid directly. Rather, they measure the copper ion content of the brake fluid. So, they are not measuring the cause but rather the effect.

There are brake fluid test devices that are affordable and that measure the moisture content of the fluid. I was going to go with one, but my research made me confident that the strips will give an early warning of any damage to the system, so that’s the way that I went.

Yes, in the Seattle area you have to be more careful of your fluid that I do. We get a lot of humidity in Minnesota, but don’t have the overall concerns with moisture that you do. I have the Infiniti in Minnesota. We are snowbirds and live in Arizona in the winter. I have a 2002 e39 in Arizona (a different one than the one that I used to have in Minnesota that used Dextron in the General Motors designed transmission, this one has a ZF designed tranny with synthetic fluid). I bought this car used, and presume that it never had brake fluid changed. It now has about 110K miles on it. I have been using these test strips to monitor it, too. On the last test the level of copper ions was beginning to rise, so I had the fluid changed this spring.