EV cars brake fluid

Author
Discussion

vw_99

Original Poster:

127 posts

44 months

Saturday 13th January
quotequote all
Not sure if the right part here.

But with the more EVs on the road, and the less "braking" due to motors or regen etc. Brake fluid is not getting used as much. So in theory more moisture built up.
And a service on a full EV is brake fluide n coolant and usual checks.

Has any manufactuar thought about a new fluid that is not hygroscopic. Its easy to add coolant but to do a brake fluid flush is a lot more involved.

darreni

3,798 posts

271 months

Saturday 13th January
quotequote all
Ev’s also rend to be heavier so more demanding on brakes.
We had an e power qashqai for the last month & the brakes front & rear are huge as I suppose they would need to be when repeatedly stopping 2 tons.

mr_spock

3,341 posts

216 months

Saturday 13th January
quotequote all
You mean something like DOT5.1 synthetic brake fluid? Yes.

vw_99

Original Poster:

127 posts

44 months

Saturday 13th January
quotequote all
Is 5.1 not just a higher boiling point?

I may well be wrong about use of brakes on a EV as i dont have one.

Jimbo.

3,950 posts

190 months

Saturday 13th January
quotequote all
darreni said:
Ev’s also rend to be heavier so more demanding on brakes.
We had an e power qashqai for the last month & the brakes front & rear are huge as I suppose they would need to be when repeatedly stopping 2 tons.
When a good chunk of the “braking” is done via regenerative braking?

Rough101

1,742 posts

76 months

Saturday 13th January
quotequote all
Just flush every 2 years like ICE cars.

Silicon brake fluid is compressible and only really used by the military.

Edited by Rough101 on Saturday 13th January 18:20

GreenV8S

30,208 posts

285 months

Saturday 13th January
quotequote all
vw_99 said:
So in theory more moisture built up.
How do you figure that? I don't see why it being an EV would make any significant difference to the water absorption rate.

vw_99

Original Poster:

127 posts

44 months

Saturday 13th January
quotequote all
Sorry my theory.
If EVs are not using brakes as much n fluid stays "still" also no clutch to help move it around either.
Not having a go at EVs just curious.

E-bmw

9,238 posts

153 months

Saturday 13th January
quotequote all
vw_99 said:
Sorry my theory.
If EVs are not using brakes as much n fluid stays "still" also no clutch to help move it around either.
Whether the fluid is stationary or moving does not change its properties or the amount of water it absorbs.

vw_99

Original Poster:

127 posts

44 months

Saturday 13th January
quotequote all
But if the fluids getting moved through tha system not just sat in tank would that not help reduce the amount of moisture it absorbs?

Not argueing just wounderning.

E-bmw

9,238 posts

153 months

Saturday 13th January
quotequote all
No.

Super Sonic

4,889 posts

55 months

Saturday 13th January
quotequote all
GreenV8S said:
How do you figure that? I don't see why it being an EV would make any significant difference to the water absorption rate.
I too was wounderning how you worked this out.

finlo

3,763 posts

204 months

Saturday 13th January
quotequote all
Super Sonic said:
GreenV8S said:
How do you figure that? I don't see why it being an EV would make any significant difference to the water absorption rate.
I too was wounderning how you worked this out.
Less usage= less heat to boil off any moisture?

vw_99

Original Poster:

127 posts

44 months

Saturday 13th January
quotequote all
Sorry
Looking back and reading 1st post i understand comments. And i am just asking question.
Maybe mentioning EVs changed the contex a bit.
It was just because going by stats they do less braking via pads n discs so to speak.

Does brake fluid on a car thats off road for 2 years have the same as one that being used 20k a year?

Maxdecel

1,230 posts

34 months

Saturday 13th January
quotequote all
From what I gather in your post you seem to imply the heat generated under braking somehow evaporates any moisture contained in the fluid?
That's incorrect, thus the need to change fluid before the fluid becomes fully moisture absorbed and corrosion starts to occur in the system itself.

Chris32345

2,086 posts

63 months

Saturday 13th January
quotequote all
vw_99 said:
Not sure if the right part here.

But with the more EVs on the road, and the less "braking" due to motors or regen etc. Brake fluid is not getting used as much. So in theory more moisture built up.
And a service on a full EV is brake fluide n coolant and usual checks.

Has any manufactuar thought about a new fluid that is not hygroscopic. Its easy to add coolant but to do a brake fluid flush is a lot more involved.
On a road car brake fluid vary rarely gets near the temp needed to boil the water In it

Mr E

21,631 posts

260 months

Saturday 13th January
quotequote all
My leaf needed brake pads at ~50k miles because they had rotted through lack of use.

I tend to try to do a “big” stop one or twice a week these days.

Mr E

21,631 posts

260 months

Saturday 13th January
quotequote all
Rough101 said:
Just flush every 2 years like ICE cars.
How many people do you think actually do that?

GreenV8S

30,208 posts

285 months

Saturday 13th January
quotequote all
Chris32345 said:
On a road car brake fluid vary rarely gets near the temp needed to boil the water In it
And if it ever does, things tend to get quite exciting.

GreenV8S

30,208 posts

285 months

Saturday 13th January
quotequote all
Mr E said:
How many people do you think actually do that?
It's easy to check the fluid moisture level and I'd expect any decent mechanic to do it during a service, together with all the other usual checks. I have no comments about how many cars are serviced by people who aren't decent mechanics.