2017 Tahoe - Brake pedal to floor - Once

[iamdub]

Is there any way to troubleshoot/diagnose this?

Have a shop or someone with a capable scan tool look for any history with the ABS, if that even exists. Failing that, have them monitor all related sensors to look for an oddity/irregularity.

 

[Doubeleive]

Is there any way to troubleshoot/diagnose this?


I did see that when searching. However, it seemed like the symptom was that the pedal would be harder to push (due to less vacuum) - this was the opposite. It was very easy to push all the way to the floor.

have the master cylinder looked at

 

[swathdiver]

It'd be nice if ABS events were stored in memory. Or have the shop live-monitor the ABS to look for irregularities.

Ours do, not sure why theirs wouldn't have it.

 

[iamdub]

Ours do, not sure why theirs wouldn't have it.

I wasn't sure, but that's great to know!

 

[tommyboy180]

vacuum leak on the brake booster. Check your vacuum hose going to the brake booster on both ends.

 

[nick14226]

Hoping someone here can give some ideas. I'm not a GM guy but a family member has a 2017 Tahoe. Last week, after driving the highway for about 30 mins, then city streets for 10-15, they turned into a parking spot. When they did and hit the brakes to stop, the pedal went to the floor and it barely had any braking power. It has < 50k miles on it.

Truck was towed back home and by the time it got back, everything was fine. Had a local shop look everything over and they couldn't find any issue. Also talked to a GM dealer and they had no idea as well.

So far, nobody can explain why this ay happened only once. My first instinct would have been a failed master cylinder, but that would not explain why everything has been fine since.

Anyone have any experience with this or ideas?

I had the brake recall done on my 17 Yukon, and it happened again to me. Brake pedal was initially soft, then hard. Cycle ignition and back to normal. It happened in a parking lot backing into a space for me as well, they say it happens during low speed maneuvers.