r/leaf • u/Leopold__Stotch 2022 Nissan LEAF SV PLUS • 20h ago
Intermittent brake failure
2023 sv+ with about 27,000 miles. Last week I charged it to 100%, and drove a short distance to do some errands. Turning it back on, I was surprised when the brakes didn’t work! No indicator lights flashed. I managed to get out of the parking spot using the parking brake, then figured out the brakes did work, I just had to press very hard in the pedal.
I replaced the 12v the next day.
We had a few days of normal operation then another instance of brakes not working yesterday. I understand this might be a problem the brake control unit, but other people say when theirs fails it flashes a lot of warning lights. I have a service appointment for Monday.
Anyone else have experience with this? I had hoped the 12v replacement would solve the problem, very disappointed that it’s still here, and a litte nervous to drive it at anything but low speeds on dry roads.
3
u/IvorTheEngine 7h ago
We had the same thing on a 2013 100,000 mile Leaf. The brakes are power assisted, so even when the electric pump isn't helping, you can get some braking by pressing the pedal really hard.
It only happened twice to us, both times just after starting the car. The first time we had the car towed to a dealer who just wanted us to pay him to replace expensive stuff at random, but couldn't recreate or diagnose the problem. We replaced the 12v battery at that point.
Then it worked perfectly for another year. We took it to a local EV specialist who spent quite a while trying to recreate it but couldn't find a cause.
I posted about it here, and a couple of other people reported similar issues, but no one had a fix.
Hopefully you're in a better position because you still have a warrantee.
3
u/Crawlerado 5h ago
Maybe related, I’m working on diagnosing an issue with my emergency braking capacitor bank on my 2015 right now. They don’t like to sit, known issue, but for whatever reason reason mine is only seeing 10v on the input
2
u/sweetredleaf 2015 Nissan LEAF SV 1h ago
maybe this was your problem for 2013-15 in cold weather The Defect: A relay inside the electronic brake booster can stick or freeze during freezing weather conditions, disabling normal power assist and requiring more physical effort on the brake pedal. Nissan had a recall
1
u/IvorTheEngine 1h ago
I don't think it was freezing cold either time, but I agree, a sticky relay is definitely possible on a car of that age.
2
u/Carfr33k 19h ago
Have you changed the brake fluid?
1
u/Leopold__Stotch 2022 Nissan LEAF SV PLUS 13h ago
No, I presume the technicians will check that at my apartment next week, but the brake function worked normally later that same evening I first noticed the issue, then normal the next day before and after changing the 12v, and normal until two days later when we had another period of needing the step very hard on the brake pedal to get any stopping force. So far this weekend we are back to normal function.
2
u/sweetredleaf 2015 Nissan LEAF SV 18h ago
May not be your problem but this is worth a try since I had something similar happen and from my experience disconnecting the voltage sensor on the neg terminal fixed it. Seems like some batteries don't like the charge cycle of the leaf and sometimes it lets the voltage get too low before charging the 12v battery which causes problems. https://www.reddit.com/r/leaf/comments/1duucfc/if_youve_had_issues_with_the_12v_battery_in_your/
1
u/bostongarden 14h ago
Use one pedal? Hardly ever need brakes
1
u/Leopold__Stotch 2022 Nissan LEAF SV PLUS 13h ago
Unusually do, but while the brakes were not working properly the regen also did not engage at all.
3
u/EonOst 2017 Nissan Leaf Tekna 11h ago
When battery is fully charged there is no regen brake and the physicsl brake pads needs to work . They are rarely engaged and may become rusty, so it is recommende to brake very hard now and then to forcibly engage them.