GerryAZ
Gold Member
Posts: 2245
Joined: Mon Nov 22, 2010 6:47 pm
Delivery Date: 12 Jun 2011
Location: Phoenix, AZ

Re: Question on Service Intervals

Tue Jun 04, 2019 6:59 pm

I have done brake fluid changes every 2 years (with every other battery check). My dealer has usually offered a discount for doing both together. I notice a firmer pedal feel after each fluid change so it is worth the expense to me. Testing the fluid in the master cylinder may not give a true indication because that is the highest point in the system and water goes to the lowest point (generally the calipers). Since there is no "engine braking" from regeneration if the battery is fully charged, the friction brakes could get quite hot during a long downhill drive so moisture in the calipers could boil and cause soft pedal feel or loss of braking effectiveness.
Gerry
Silver LEAF 2011 SL rear ended (totaled) by in-attentive driver 1/4/2015 at 50,422 miles
Silver LEAF 2015 SL purchased 2/7/2015; traded 8/10/2019 at 82,436 miles
White LEAF 2019 SL+ purchased 8/10/2019

powersurge
Posts: 1464
Joined: Wed Oct 21, 2015 10:24 am
Delivery Date: 06 Dec 2014
Location: Long Island, NY

Re: Question on Service Intervals

Wed Jun 05, 2019 6:30 am

SageBrush wrote:
gncndad wrote:Replacing brake fluid is cheap maintenance, to protect all components from rust/corrosion. We all know brake fluid is hygroscopic, so time is as critical as mileage. I will stay with 3 year brake fluid replacement interval, regardless of mileage, based on many, many years of experience.
Your experience is with cars that do not use regenerative brakes
Are You disagreeing with the man?

Since the Leaf Has no maintenance to speak of, then it can only be smart to change the transmission fluid AND Brake Fluid every 40K miles. And if you do not drive a lot, change the brake fluid every 3-4 years. Everything is very cheap and it is nice to have nice clean fluids regularly.

If you disagree, that is your own business, but do not tell other Leaf drivers and non-mechanical people that it is not necessary....

Oilpan4
Gold Member
Posts: 761
Joined: Wed Jan 09, 2019 10:51 pm
Delivery Date: 10 May 2018
Leaf Number: 004270

Re: Question on Service Intervals

Wed Jun 05, 2019 9:55 am

Brake fluid is hygroscopic.
Regen doesn't matter.
The brake fluid is going to continue to absorb water, the brake system is make of steel and other dissimilar metals which will be eaten away over time.

The reaction between water, brake fluid and metals in the brake system will break down and form gases.

I sure as hell wouldn't pay a dealer to do it. Just suck the old brake fluid out of the reservoir with some sort of fluid sucking implement, wipe out the left over gunk in the bottom of the reservoir with a lint free shop paper towel, refill with fresh fluid from a factory sealed container, bleed brakes and refill as needed.

If anyone thinks the leaf needs no preventative maintenance like this then all I can say is ignorance is bliss.
2011 white SL leaf with 2014 batt.
Chargers: Panasonic brick moded for 240v, duosida 16a 240v and a 10kw setec portable CHAdeMO
Location: 88103

LeftieBiker
Moderator
Posts: 12977
Joined: Wed May 22, 2013 3:17 am
Delivery Date: 30 Apr 2018
Location: Upstate New York, US

Re: Question on Service Intervals

Wed Jun 05, 2019 11:46 am

Brake fluid is hygroscopic.
Regen doesn't matter.
The brake fluid is going to continue to absorb water, the brake system is make of steel and other dissimilar metals which will be eaten away over time.
Water usually enters the brake system through the reservoir. EVs tend to have much lower brake wear, so the brake fluid drops more slowly and the fluid level gets checked less frequently (except visually, through the translucent reservoir body) and the cap is removed less often. The end result is less water in the brake fluid. No one is arguing for zero maintenance, just that replacing the brake fluid every year (and even every two years) is usually unnecessary.
Scarlet Ember 2018 Leaf SL W/ Pro Pilot
2009 Vectrix VX-1 W/18 Leaf modules, & 3 EZIP E-bicycles.
BAFX OBDII Dongle
PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

gncndad
Posts: 136
Joined: Mon Feb 22, 2016 9:02 pm
Delivery Date: 23 Feb 2016
Location: Ft. Worth, TX

Re: Question on Service Intervals

Wed Jun 05, 2019 1:11 pm

LeftieBiker wrote:
Brake fluid is hygroscopic.
Regen doesn't matter.
The brake fluid is going to continue to absorb water, the brake system is make of steel and other dissimilar metals which will be eaten away over time.
Water usually enters the brake system through the reservoir. EVs tend to have much lower brake wear, so the brake fluid drops more slowly and the fluid level gets checked less frequently (except visually, through the translucent reservoir body) and the cap is removed less often. The end result is less water in the brake fluid. No one is arguing for zero maintenance, just that replacing the brake fluid every year (and even every two years) is usually unnecessary.
All good points.
I will stay with 3 year changes in ANY hydraulic brake system, whether or not it has regen capabilities. CHEAP!!!!!
2015 LeafS
2013 Ford Cmax
2014 Toyota Avalon Hybrid Limited
2017 Ford Fusion Hybrid Energi

derkraut
Posts: 1517
Joined: Fri Jul 16, 2010 7:39 pm
Delivery Date: 14 Jun 2011
Leaf Number: 004248
Location: San Diego vicinity

Re: Question on Service Intervals

Wed Jun 05, 2019 10:02 pm

SageBrush wrote:Ignore that useless battery check with the pride that comes from saving $100. Your warranty is safe without it.
Right on, Sagebrush. Stay away from a Nissan dealer for everything except items covered under warranty. There are much better ways to spend your hard-earned money.
Derkraut
Color: Cayenne SLE, ETEC trim
reserved: 5/15/2010
Leaf del. 6/14/2011
New Traction battery installed on 7/28/2017:

SageBrush
Posts: 4737
Joined: Sun Mar 06, 2011 2:28 am
Delivery Date: 13 Feb 2017
Location: NM

Re: Question on Service Intervals

Fri Jun 07, 2019 7:16 am

Oilpan4 wrote:Brake fluid is hygroscopic.
Regen doesn't matter.
The brake fluid is going to continue to absorb water, the brake system is make of steel and other dissimilar metals which will be eaten away over time.
I rely on the advice and teaching of a fellow who calls himself 'hobbit' on the internet (presumably related to his tendency to walk around bare-foot.) Make no mistake though, this guy is an MIT trained engineer and one smart dude. He is probably one of the top 5 Prius hackers in the world.

On the subject of brakes he writes (as part of his 100k maintenance)
On a slightly different tangent ... after 5 years, what state is the brake fluid in? Many people would expect it to be way overdue for a flush/replacement. There are numerous articles and posts floating around on brake fluid and its affinity for water and how the more water content it collects, the more likely it is to corrode internal brake system parts and boil into vapor under severe heating and cause spongy braking. The forums are full of self-styled "experts" telling each other that no brake fluid can possibly be any good after two or three years, and when the ambient babble gets loud enough one might be tempted to start believing it.
Not so fast, bucko.
The remainder of his investigation and conclusions are here:
http://techno-fandom.org/~hobbit/cars/maint100k/
Starting from the 'Brake Fluid' section.
2013 LEAF 'S' Model with QC & rear-view camera
Bought off-lease Jan 2017 from N. California
Two years in Colorado, now in NM
03/2018: 58 Ahr, 28k miles
11/2018: 56.16 Ahr, 30k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

Goodbar
Posts: 28
Joined: Wed Sep 20, 2017 6:39 am
Delivery Date: 31 Jul 2017
Location: Washington, D.C. Metro

Re: Question on Service Intervals

Fri Jun 07, 2019 7:45 am

SageBrush wrote:
Oilpan4 wrote:Brake fluid is hygroscopic.
Regen doesn't matter.
The brake fluid is going to continue to absorb water, the brake system is make of steel and other dissimilar metals which will be eaten away over time.
I rely on the advice and teaching of a fellow who calls himself 'hobbit' on the internet (presumably related to his tendency to walk around bare-foot.) Make no mistake though, this guy is an MIT trained engineer and one smart dude. He is probably one of the top 5 Prius hackers in the world.

On the subject of brakes he writes (as part of his 100k maintenance)
On a slightly different tangent ... after 5 years, what state is the brake fluid in? Many people would expect it to be way overdue for a flush/replacement. There are numerous articles and posts floating around on brake fluid and its affinity for water and how the more water content it collects, the more likely it is to corrode internal brake system parts and boil into vapor under severe heating and cause spongy braking. The forums are full of self-styled "experts" telling each other that no brake fluid can possibly be any good after two or three years, and when the ambient babble gets loud enough one might be tempted to start believing it.
Not so fast, bucko.
The remainder of his investigation and conclusions are here:
http://techno-fandom.org/~hobbit/cars/maint100k/
Starting from the 'Brake Fluid' section.
Interesting read. I've owned a Gen 2 Prius and bled the brakes on it, in addition to replacing the rear shoes. I haven't done a detailed comparison of how the braking systems differ, though the procedure/precautions on the Prius are less conventional than the Leaf. Also, perhaps Toyota is using superior materials, extending the life of the fluid?

I will say that I was surprised at how dirty and dark the original brake fluid was on my '17 Leaf after less than two years and a modest 15k miles. It was dirtier than I would have expected from a conventional car without regen, especially because I try to maximize regen when practical. But, my experience is just one data point. I think the Nissan maintenance schedule is a little out of whack with reality, though given what I saw this time, I will probably replace the brake fluid in another two years. By far the greatest benefit to fluid replacement for me was getting a firm brake pedal with a more progressive transition from regen to friction braking. It feels better than when new, though it could just be confirmation bias ;)
2017 Leaf SV OpenEVSE 40A

Oilpan4
Gold Member
Posts: 761
Joined: Wed Jan 09, 2019 10:51 pm
Delivery Date: 10 May 2018
Leaf Number: 004270

Re: Question on Service Intervals

Fri Jun 07, 2019 11:18 am

Dot 5 silicone based brake fluid is more than likely still fine after 5 years.
2011 white SL leaf with 2014 batt.
Chargers: Panasonic brick moded for 240v, duosida 16a 240v and a 10kw setec portable CHAdeMO
Location: 88103

Goodbar
Posts: 28
Joined: Wed Sep 20, 2017 6:39 am
Delivery Date: 31 Jul 2017
Location: Washington, D.C. Metro

Re: Question on Service Intervals

Fri Jun 07, 2019 11:29 am

Oilpan4 wrote:Dot 5 silicone based brake fluid is more than likely still fine after 5 years.
That's probably true, but DOT 5 is not recommended for ABS-equipped cars:
https://onestopauto.com/Can-DOT-5-Brake ... 3-or4.html
2017 Leaf SV OpenEVSE 40A

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