W205 rear brake pad replacement

[SBSP]

Evening all, I have a C220 D C class estate AMG line (2016) love the car and needs new rear pads.
Thought I’d sort myself as an easy job lol. I started by ensuring the correct pad fitting position was reached using phone/ok buttons with rear electronic brake retracted, all good but I can’t get the piston to retract enough manually? And seems miles of fitting the new pads in. Push/turn clockwise/anti-clockwise etc etc, am I missing something? Is there a special windback tool?
Thanks in advance James

 

[ernie]

Pads should retract sufficiently using the software system. Don't force anything to make them fit, though. the pistons should go back till they are flush with the bore of the caliper. MB pads should fit OK. If not MB, maybe the lining is too thick or they are the wrong pads? Have you tried to retract them again?

Ernie

 

[SBSP]

Pads should retract sufficiently using the software system. Don't force anything to make them fit, though. the pistons should go back till they are flush with the bore of the caliper. MB pads should fit OK. If not MB, maybe the lining is too thick or they are the wrong pads? Have you tried to retract them again?

Ernie

Thanks Ernie, they are genuine Mercedes Pads sourced from main dealer with chassis number. The setting to get them into service position only retracts the EPB as far as I know, so you still need to manually retract the pistons, at the moment they aren’t anywhere near flush. And I can’t find any detailed info on how to get them in, whether it’s turning clockwise/anti-clockwise or both, and if there is a specific tool, I can turn the piston easily but hard to get any inward pressure with pliers.

 

[ernie]

Thanks Ernie, they are genuine Mercedes Pads sourced from main dealer with chassis number. The setting to get them into service position only retracts the EPB as far as I know, so you still need to manually retract the pistons, at the moment they aren’t anywhere near flush. And I can’t find any detailed info on how to get them in, whether it’s turning clockwise/anti-clockwise or both, and if there is a specific tool, I can turn the piston easily but hard to get any inward pressure with pliers.

You probably won't get enough pressure with pliers, as you found. I normally use a G-cramp or even a long screwdriver to push them in, but be careful you don't nip and damage the dust seals. Also check that the level of fluid in the master cylinder isn't too high and trying to come out of the vent hole. You could try Halfords or a trade parts stockists to see if they stock a generic tool for retracting brake cylinders if you want to do it 'properly'!

Ernie

 

[ioweddie]

small block of wood lever with strong screwdriver

 

[Trickythemerc]

My take on this is simple. If you don't have the right tools for the job leave it alone, or invest in the correct tooling. I have tools in my box that have maybe only used a couple of times, my brake caliper rewind set being one of them I bought it to do the rear pads on my Jag. I could have bought the single application tool for £20.00 but went for a more comprehensive kit that covers most makes of car/calipers. The benefit of using correct tools is that you can be confident that you won't be risking any damage to seals etc.

What is all this about pushing pistons back without opening the bleed nipples, it's madness. You run the risk of flipping a seal in its bore and the fluid in the caliper chambers gets pushed back up the lines, that is actually the last place you need it to be. The fluid will have been subjected to more hot cold cycles than enough, so why would you want to keep it in the system anymore the you would top up your engine with used sump oil.

 

[gazz01]

Evening all, I have a C220 D C class estate AMG line (2016) love the car and needs new rear pads.
Thought I’d sort myself as an easy job lol. I started by ensuring the correct pad fitting position was reached using phone/ok buttons with rear electronic brake retracted, all good but I can’t get the piston to retract enough manually? And seems miles of fitting the new pads in. Push/turn clockwise/anti-clockwise etc etc, am I missing something? Is there a special windback tool?
Thanks in advance James

 

[gazz01]

make sure the electric parking brake is disengaged before you do the service position.good luck.