2020 Sierra - Rear brake piston fully extended and unable to retract it.

[ajs800]

I was in the process of replacing rear pads and rotors and made the mistake of putting it in brake service mode after removing the rotor and the piston fully extended and is fully stuck out. 

 

The question I have is, am I screwed or will I be able to still retract it with the proper tool?  I already replaced the other side and was aware of the service mode but made the mistake and attempted to do it without the rotor installed so the piston had no resistance and just fully extended all the way out.  I'm hoping it's not damaged and will still retract.  I'm hoping to get the tool today but unsure if it will work being the piston is fully extended.  Any tips or advice would be appreciative  as of right now I'm unable to move the truck. 

Edited August 25, 2023 by ajs800

[silveradosid]

try cracking open the bleed screw a push it back in slowly

[ajs800]

Thanks. I picked up the brake repair kit today and will attempt to retract it back in far enough to get orig  pads and rotor installed   If I can get it back in far enough I’ll reinstall rotor and go through the service mode steps again and let it retract fully .

[Ididit2]

On 8/26/2023 at 5:01 PM, ajs800 said:

I just did this same thing and can't figure it out. What was your solution?

 

[Kbel12]

I did the same thing as well, any solution @Ididit2?

[Joelm92]

So hello guys 

same ****** happened to me on both back pistons fully came out. 
but the worst part about mine is the piston gasket ripped so I have to replace it. Waiting for parts to come in then I’ll try putting the piston back in. I’ll let you guys know if it’s successful if not will need to replace the whole caliper which isn’t too expensive but us trying to save money . We live and we learn. 

[Joelm92]

On 6/2/2024 at 1:59 PM, Kbel12 said:

I did the same thing as well, any solution @Ididit2?

Have you fixed it?

[mayhem719]

Yep did the same thing let the piston extend fully without anything ro give it push back and now here I am stuck with one ehrel off snd csnt retract it to get the caliper over the new brake pads he'll I don't even know if I could get it over the old ones as far as it's out. I have seen these posts but nothing to solve the issue am I missing part of the forum here!! 

[mayhem719]

Guess imma try the bleed screw and see if that gives me and play to get them to decompress to get the caliper over the damn brske pads. Wish me luck snd I'll let you know if it worked or not. 

[silveradosid]

you have to put slight pressure against the piston and turn at the same time, to much pressure it wont turn