brake warning light is on under panic stop

[nospamagain]

Hi, first time be here to ask some advices.

I have a weird question troubled me for a long time.

The brake warning light will turn on when doing really hard stop and there is no ABS action at that time. it won't be on under normal situation. Turn off the key and start the car again will clear the warning light.

I thought it maybe the ABS problem and did try panic stop on a dirty sandy road. To my surprise, there is no problem at all and I could feel the ABS brake feedback when I do brake. Of course the speed is not high since it's a narrow sandy trail.

It seems that the light will turn red only when I do panic stop in high speed on hard pavement road.

My question is: what's the possible cause for that and how to fix it. Anyone had similar experience?

By the way, my LC100 has ABS,VSC and TRAC.

 

[Muddy Bean]

Sorry to state the obvious, but is your brake fluid level low? Does that to me when my level is low.

 

[nospamagain]

Sorry to state the obvious, but is your brake fluid level low? Does that to me when my level is low.

Thanks for the reply. It's definitely not brake fluid level.

The brake warning could triggered by the brake fluid level. But in my case it only happens in panic stop. ABS system works in low speed situation.

I thought that maybe brake warning light caused by low brake hydraulic pressure when doing high speed panic stop which needs very high pressure to operate the ABS system since there is no LSPV to automatically adjust pressure.

 

[OregonLC]

I'd bleed the system and try again. If that doesn't help then you probably have a soft pump that's not maintaining pressure.

 

[PADDO]

I'd bleed the system and try again. If that doesn't help then you probably have a soft pump that's not maintaining pressure.

Maybe a case where another bleeding is necessary due to the OP seemingly pushing the braking system to its limits? I've noticed the ABS bleeding tab in TechStream but haven't experimented with it, some posters refer to a "dealer bleed" (where they use TechStream) and the StopTech web site help pages talk about the proper way to bleed most ABS brake is 1. conventional 4 point bleed 2. cycle/activate ABS system to open the ABS hydraulics to the primary braking hydraulics and 3. repeat conventional 4 point bleed. Any one with experience with dealer/TechStream ABS bleeding?

Sent from my iPhone using IH8MUD

 

[OregonLC]

Maybe a case where another bleeding is necessary due to the OP seemingly pushing the braking system to its limits? I've noticed the ABS bleeding tab in TechStream but haven't experimented with it, some posters refer to a "dealer bleed" (where they use TechStream) and the StopTech web site help pages talk about the proper way to bleed most ABS brake is 1. conventional 4 point bleed 2. cycle/activate ABS system to open the ABS hydraulics to the primary braking hydraulics and 3. repeat conventional 4 point bleed. Any one with experience with dealer/TechStream ABS bleeding?

Sent from my iPhone using IH8MUD

There's a FAQ here somewhere. IIRC you bleed the rear with the pump (key) on and the front with it off. May have that backwards.

 

[nospamagain]

I'd bleed the system and try again. If that doesn't help then you probably have a soft pump that's not maintaining pressure.

Thanks. I will do the suggested bleed after some sandy trail driving in next week and report the result.