Hyper extended parking brake piston while caliper removed; 2021 Kona EV

Situation: My wife's 2021 Kona EV. My yearly R&R of the winter tires with the all seasons; also my yearly lubrication of the brake calipers/caliper slider pins. I did a Homer whilst the rear left caliper was removed...I set the electric parking brake and naturally the piston hyper extended.



So, I manually screwed the piston back into the caliper, put everything back together and turned the car on and off several times...

...but I still have a Christmas tree full of brake system warning lamps that I don't know how to extinguish.

Also, I can hear the brake e-master cylinder clicking whenever I apply the brakes...

The car is drive-able, but brake regen is not being allowed, and I suspect the anti-lock system is also not being allowed.

I booked an appointment (for 1630 on 11 Apr 2023) at the local dealer; the service guy right away is saying it will probably need a new caliper.

Anyhow: does anyone here know of some magic trick (I don't have an OBD2 tool anymore) where I can reset the system (such as a series of brake pushes and signal stalk pushes) via some home-mechanic hack?

Thanks.

 

Yes, its not being driven until I bring it in Tuesday.

If they can clear the codes and then do a simple test drive to confirm serviceability, so much the better.

At the end of the day, it’s just another valuable lesson learned.

 

Thanks.


FYI: in the video the rear pads aren’t “stuck” because of corrosion, they are “locked” in place by small (think fish hook) one way barbs in the pad retaining clips. I use a fine set of needle nose pliers to compress one of the barbs enough to allow the one pad end to pass over it and come out of the retainer clips..

 

Closure: the dealership just needed to connect their computer and clear the codes.

System now operating in accordance with manufacturers specifications.

$CA197.69.

Still much cheaper than paying them to do the routine brake servicing.

 

It is a totally different action, but AFAIK it is a typical way to move the piston on any of these e-brake type emergency brakes. Of course, YMMV.

 

Post script: my wife complained about hearing a "hissing noise" when the service brake pedal was applied.

Confirmed the noise was coming from the e-booster/master cylinder area.

I brought it back in to Hyundai, I recommended they do a brake bleed (replaced all the brake fluid) and that solved the issue.

$432.67 for two hours of labour and brake fluid.

 

For this one time, yes.

I’ll never make the same Homer Simpson error again.

…But they charge $345.00 plus HST for routine brake servicing (i.e. once a year caliper lubrication), so I’m still at less cost than two years of having the dealership lubricate the calipers.