Brakes grabbing when coming to a stop

[Ry Cizzle]

I have this exact same situation happen regularly, even if coming to a stop light with nobody in front of me. That led me to believe it's the switch between regen and hydraulic braking.

OK, maybe it is this then. I've had PDA off for over a year and just confirmed it is still off. Is there any documentation or info about how the switchfrom regen to hydraulic braking system works? I would think that a "normal" system process would be pretty consistent but this issue is very sporardic.

 

[Pavman2473]

I’ve had mine for about a year now. It happens infrequently. I’ve heard it was due to regen braking etc.

 

[ultane]

I have this exact same situation happen regularly, even if coming to a stop light with nobody in front of me. That led me to believe it's the switch between regen and hydraulic braking.

The Car Care Nut seems to think that this is the case on one of his videos.

 

[ycart1201]

I have noticed this on occasion. I assumed it had something to do with regenerating the hybrid battery although my tundra doesn’t do it (it has the iforcemax motor).
I’m following to see if we get a definitive answer.

 

[TurboLC24t]

Are you sure it is not a hard downshift or a regen braking issue? Are there any beeps or warnings when it happens?

 

[sprnkls]

Are you sure it is not a hard downshift or a regen braking issue? Are there any beeps or warnings when it happens?

Personally, I've only had it happen the one time, but I could definitely see it being something like the regen kicking in at the same time as a downshift, causing it to feel like the brakes suddenly grabbed hard.

 

[hikerdrg]

I was wondering, when the LC starts to brake because of a car in front of you or regen braking does the rear tail lights come on to alert the driver behind you that the LC is slowing down?

 

[AustinLC250]

Are you sure it is not a hard downshift or a regen braking issue? Are there any beeps or warnings when it happens?

It could be a combination, but mine always happens at about 5-10 MPH while braking. There are no beeps or warnings, and my PDA has been off.

 

[4cornersexplorer]

I've just assumed this is more of the transmission / hybrid system quirks. It's startling enough that I've been concerned about getting rear-ended at traffic circles. Though it's probably not as bad as I imagine it is.

I've experienced it as well and I don't think it is the breaks. I think its transmission or something to do with the regenerative breaking feature, but not actual break pad pressure. I notice it mostly when in Economy drive mode and always as I'm slowing to a stop under 10 mph.

 

[Bad1975]

I was wondering, when the LC starts to brake because of a car in front of you or regen braking does the rear tail lights come on to alert the driver behind you that the LC is slowing down?

Yes, when auto braking occurs the tail lights turn on. You can have the tail light indicators on the dash to monitor if desired, don't remember the setting or menu, but it shows two little red lines in the bottom corners of the DIM when ever you or the LC is braking.

 

[Ike582]

Yes, when auto braking occurs the tail lights turn on. You can have the tail light indicators on the dash to monitor if desired, don't remember the setting or menu, but it shows two little red lines in the bottom corners of the DIM when ever you or the LC is braking.

Yes, every time it happens those two tail light indicators on the lower part of the dash turn red.

 

[TakaraLC]

Regen breaking cuts of below a certain speed (like 10MPH or so). So I think what is described here is regen disengaging and friction breakers engaging.

As regen breaking doesn’t generate a constant breaking power (it is dependent on battery charge level). Computer tries adjusting the amount of friction braking based on the level of regen breaking, but for some people, it may not be doing a good job.

In first gen Prius, this was not present and it would feel like you suddenly lost breaking power when regen cutoff.

 

[Meteor]

Reviving this thread.

Has anyone noticed this not being an issue since the TSB was performed for the squealing brake when reversing? I've not felt it in the two weeks since the dealer performed the repair. Maybe there was a software update to address the issue as well?

 

[sprnkls]

I actually did have it happen again a couple days ago, but not quite as severely as the first time. I'm definitely leaning towards it being a coincidental combination of multiple things happening at once, like brake regen, a downshift, jumping from auto braking to manual, etc. At least that seems to be the most likely explanation given the circumstances of the couple times it's happened to me.

 

[LCOceans]

I was noticing this a lot when I first bought the truck but seems to have gone away for the most part as of a few months ago. I never had any brake squeal though that so many talk about.
I also seem to recall the brake grab thing being attributed to brake regeneration and also driving in ECO mode, or at least seem to recall being in Normal or Sport alleviates the issue.

 

[wpage]

The complexity of this machine, makes me wonder if a combination of factors are causing this grab. As others have pointed to the problem.
-Battery charges off braking energy.
-Safety features enabled to prevent rear ending other motorists.
-Mode chosen for driving conditions.
-Transmission switching from hybrid motors to ICE.

When adding up variable factors. Its a crap shoot to understand the culprit.

I look at it similar to wrestling with steering with using the lane assist. Take the good with the bad...

 

[lar317]

Have you had your brakes fixed for the brake squeal TSB, I just traded in my 2025 Toyota 4Runner SR5 for a used 2025 LC1958, The 4Runner had the squeal and the brakes grabbing, I had the brakes fixed on the TSB, All good now no grabbing or squeal, I will have LC done when I get the time, The LC also squeals in reverse and brakes grab a little. There is a TSB for the LC also.

 

[shwazz714]

Think Lexus has a tsb for this so I’m guessing Toyota will have it as well down the line

 

[ultane]

Have you had your brakes fixed for the brake squeal TSB, I just traded in my 2025 Toyota 4Runner SR5 for a used 2025 LC1958, The 4Runner had the squeal and the brakes grabbing, I had the brakes fixed on the TSB, All good now no grabbing or squeal, I will have LC done when I get the time, The LC also squeals in reverse and brakes grab a little. There is a TSB for the LC also.

Welcome to the asylum.

 

[lar317]

• TSB-0046-25
• This is the Toyota service bulletin for the LC brakes