Rear Brake Caliper Piston Issue
Member
Joined: Nov 2011
Posts: 109
Likes: 5
From: DFW
W222 S550, W218 CLS63, W166 ML550, Titan, Sentra
Newbie
Joined: Dec 2024
Posts: 2
Likes: 0
cla 200
Hey Folks,
i had the back caliper over extend on me as well. Thankfully there is an easy solution.
1) use a c clamp carefully push to piston in till it rests against the extended internal parking brake screw. Push on the center.
2) Now the dash control will let you go to the retracted service position.
3). Use the c clamp again to push the piston all the way in.
4) replace pads and put back together. Use dash menu to put parking drake in operating position. All good now.
Dealer as usual is full of it. Easy fix!!
Paul.
i had the back caliper over extend on me as well. Thankfully there is an easy solution.
1) use a c clamp carefully push to piston in till it rests against the extended internal parking brake screw. Push on the center.
2) Now the dash control will let you go to the retracted service position.
3). Use the c clamp again to push the piston all the way in.
4) replace pads and put back together. Use dash menu to put parking drake in operating position. All good now.
Dealer as usual is full of it. Easy fix!!
Paul.
Man i made an account just to thank you for this!
I was in all sorts of anger after being stupid and pressing okay on the pad change function before i was finished resulting in the over extended pistons.
after a few tantrums I gave up went inside and happened too read this, I went back out put a C clamp against the piston a thick rag too cover the casing behind, after that i applied just enough pressure to trick the dashboard into thinking I had the pads installed this then allowed me to activate the pad change sequence again and push the piston in the rest of the way by hand with ease
THANK YOU MAN!!!!!!!!!
Newbie
Joined: Mar 2026
Posts: 1
Likes: 0
2017 C63s
Man i made an account just to thank you for this!
I was in all sorts of anger after being stupid and pressing okay on the pad change function before i was finished resulting in the over extended pistons.
after a few tantrums I gave up went inside and happened too read this, I went back out put a C clamp against the piston a thick rag too cover the casing behind, after that i applied just enough pressure to trick the dashboard into thinking I had the pads installed this then allowed me to activate the pad change sequence again and push the piston in the rest of the way by hand with ease THANK YOU MAN!!!!!!!!!
I was in all sorts of anger after being stupid and pressing okay on the pad change function before i was finished resulting in the over extended pistons.
after a few tantrums I gave up went inside and happened too read this, I went back out put a C clamp against the piston a thick rag too cover the casing behind, after that i applied just enough pressure to trick the dashboard into thinking I had the pads installed this then allowed me to activate the pad change sequence again and push the piston in the rest of the way by hand with ease
THANK YOU MAN!!!!!!!!!The question I have for you sir is that c-clamp did you use to push the piston is? As on the AMG TRW brake systems, the calipers have a name plate on top.
Any help is appreciated! thank you.
