2019 Caliper issues

Kimble1986 said:

I have a 2019 Pacifica sport and when I started to retract the brakes in the LCD screen the caliper wouldn’t retract. The screen told me the caliper was retracted and that was not the case. The screen also mentioned to get out of service mode, press the brake and push the parking brake. So I did so and my entire caliper piston shot out with brake fluid everywhere. I’m not a certified mechanic by any means. I Do however learn fast and need some serious help. This is my family’s only means of transport. Is my caliper done? Do I need a new one? I’ll try and post a picture with this. View attachment 50898

Click to expand...

You will likely need a piston rebuild kit if there is one. You should replace the piston seal and the dust boot. There may be no damage and you could just carefully reassemble it as is but as cheap as these are, you might as well just replace them. You should never apply brakes with no pads/rotor in place unless your intent is to extract the piston (which you’ve done).

And by the way, there normally is no way to retract a brake piston without mechanical persuasion. That would require negative hydraulic pressure (suction). What you have done is to extend the piston beyond its normal operating limits because you disassembled the caliper and left the pads behind. When you applied the brakes there was nothing to keep the piston from simply pushing out of the caliper.

Another thing to keep in mind. The brakes on your car are “life safety” items. In other words, if they don’t operate correctly it could kill you. There is nothing wrong with working on brakes yourself if you know what you’re doing. Don’t simply experiment or say to yourself, “I think this is the way it’s supposed to be”. Lives are at stake. Make sure you know the job and you do it right. Ask someone who’s done a brake job before to look over your shoulder.

And just another thought: the retraction of a brake cylinder is normally done to make room for new brake pads that are being installed. If there is some option in a service menu for retracting them I can only assume that it simply releases some sort of check valve somewhere and allows you to then manually retract the piston. I usually do this with a large screwdriver as a lever to put pressure against the piston and make it retract back inside the caliper. Most cars allow you to do this without any special preparations.

thclimer said:

On our 2019 I thought you had to twist the rear caliper as well and almost purchased a tool to do so as I had seen some YouTube video's showing this. However, once I had disassembled it there were no holes for the tool to twist the caliper piston and to my surprise it was pretty easy to compress as compared to some front calipers where I have used a large C-clamp.

Maybe the twisting is required on 2020 and newer Pacifica's?

Click to expand...

You should be able to tell if the piston needs to be twisted in by looking for notches on the part of the cylinder that makes contact with the pad. If there are notches on the piston then it will likely need to be twisted when it’s retracted so that it can engage correctly with the parking brake mechanism.