cpyue

Wednesday morning, -10 deg C, I warmed up my 2020 NX300 (got only 960km on odometer). It has winter tires equipped. After driving around 7 min, stopped at 3 STOP sign with snow and ice, and 2 Red light. Entered in to another residential area with speed limit 40 km/h. At a cross junction ALLWAY STOP sign, I tried to apply brake prepare to slow/stop, I found my foot like pressing on concrete - NO BRAKE. The NX kept "rolling", and shot over the cross junction, I keep pumping the brake. After a few seconds more, the brake comes back, but I'd already passed the junction. Luckily there's no other cars/people at the cross junction. After that brake failed incident, no more brake fail again. I brought the vehicle to dealership today for emergency examination. Their mechanic test drove the vehicle with me, then OBD computer checked but found no error/alert. Reasons I think: (1) I cannot press the brake paddle down at all, look like the brake paddle is welded on. (2) Also the vehicle was still "rolling" and shot pass the cross junction.

Anyone has similar experience?

PS: (I tried to attached a car cam video, but seems I cannot attached it here).

no1SomeGuy

ABS activated on pure ice?

cpyue

no ABS, no nothing, brake never applied. As I have said, the brake paddle like welded on. So the NX kept rolling forward.

gulshan

Dude what a coincidence. I had the exact same experience. 2016 base nx awd. Except I slid on the main highway and narrowly (literally inches) avoided a massive semi . In avoiding me he clipped another car .. Luckily no one hurt or killed in this multi car incident.. Basically it was patches of ice on the side street covered in lite snow. Nothing wrong with the car. If i was real slow and careful could have avoided. Having said that I wish the brakes were better like some of my other cars (bmw, honda etc). They don't have a bite. Rather soft and spongy like most toyotas/lexus. Need getting used to .. and if you switch cars frequently when have multiple cars it is hard to mentally adjust your braking habits.. Winter tires no use on ice. Maybe chains some help. But with chains you are driving slower anyway..

cpyue

Agreed we are all lucky. But my case is different from yours. When I tried to apply the brake, brake paddle just like "welded" on the car body. Just like you "stamped" on concrete. I don't know how these days brake works, I just believe that something loose and fell behind the paddle, prevented it from pressing down. After I "stamped" hard many times, maybe that object moved aside and the brake works again. Will send to dealership again soon for a more detail check.

olgzr

I can only think of one possibility. I believe there’s a check valve between the engine and the brake booster. It may be built into the brake booster. It traps vacuum in the booster when the engine is not running. If it had a little moisture on it and froze overnight, you would have brakes until the vacuum was used up, then the pedal would be very difficult to move. It would take a lot more pressure than normal to apply the brakes. The heat from the engine may have thawed the ice after several minutes of driving which allowed the brakes to start operating again.

cpyue

Sounds like what happened on my 2020 NX. I will reluctant to continue to drive this vehicle if they cannot find out the reason that cause the brake failed.

cpyue

Hi logzr, do you think once this happened and passed, will it already got rid of the frozen ice at the same time, and there will only be vacuum inside the brake booster? or the frozen ice will still trap inside, and will brake will fail again?

ultra63

i had a similar problem in a Lexus that turned out to be a defective master brake cylinder https://www.clublexus.com/forums/ls-...-04-ls430.html. as a public sevice you can report dangerous defects to NHTSA

olgzr

I really don’t know and am just speculating here but if there was moisture in the master cylinder or check valve, I see no way of it disappearing. I would like to see the dealer checking the master cylinder or the check valve if it’s external to the master cylinder. If it’s internal, I would also like to see the master cylinder replaced.

cpyue

Very sad, I have a "Suicide Car" now. Yesterday, I sent in my brake failed NX300 to dealership for detail investigation. Today, they told me no faulty found, and released the car back to me. I have talked to the General Manager of the dealership, but he said the same thing. He emphasis that is nowadays' new ABS work, to keep the car straight. But to me, ABS not only to keep car straight, but must also done some braking to slow down the car at the same time. But when my car brake failed, I only noticed the brake paddle cannot press down at all, and the car has no sign of slowing down due to my hard braking. It slowed down only because I did not give any gas. What approach I should take now?