Yaris 2017 - weird sound in the morning

[Rqss]

Hi, I have Yaris 2017 hybrid, and for the past couple of mornings it is making odd sound in the morning. Car turns on fine, but after shifting to drive mode, it doesn't immediately move as normal with automatic. After pressing accelerator, it starts finally moving but does this loud popping sound. First, I thought i drove over some plastic bottle which wasn't the case, and it has now happened a couple of times. Has anyone else had similar issues? Could this be weather related when nights get a bit colder/wetter or should I be concerned? 

[flash22]

It's the caliper/pad sticking, mine does it, it's the temperature drop and the disc flash rusting

Put it in to park, lift your foot off the brake a little, then apply the handbrake, that seems to stop it happening for me

[Rqss]

36 minutes ago, flash22 said:

It's the caliper/pad sticking, mine does it, it's the temperature drop and the disc flash rusting

Put it in to park, lift your foot off the brake a little, then apply the handbrake, that seems to stop it happening for me

Many thanks, that's really helpful - I'll try that. I still have 12 month Toyota warranty (as I have bought it recently) and i guess if it keeps happening, i'll try to get them look at it

[Gerg]

1 hour ago, Rqss said:

Has anyone else had similar issues?

Exactly as flash22 says above.  This seems common to many Toyota hybrids - probably a greater number of Auris owners complaining of it on this forum though - if you wanted to do a search on other posts.

The hybrid regenerative braking means that the normal brakes dont get that hot, and the back brakes barely get warm sometimes.  Which means the car is getting parked with damp rear brakes.  It will be slightly worse if the car has been static for a few days, or if the roads have been salted.

If you try to view the (hopefully shiny) rear brake disks through the wheel spokes, you may be able to see radial, but curvy, 'witness marks' from where the pads have rusted to the disk previously.

[Catlover]

Is this anything different to most/all cars parked out in the open - damp  mornings, stiction as Flash22 says.  Pretty normal I would think, no need to panic.

[flash22]

On the Yaris the handbrake is essentially a cam that pushes on the rear of the piston, if you hold the foot brake down fluid pushes the cylinder out, at the end of its travel it has max pushing force the pad clamps the disc, the handbrake can technically hold it in the clamped position