Changing front pads on R231 SL400 - advice please

[Altamar]

Hi all

I am about to change the FRONT brake pads on the SL. I am an experienced DIYer and have changed pads and discs on many family cars. I also have a tool to press back the caliper (and a wind back tool if I was doing rears without electronic brakes)

My question though is do I just push back the (twin) calipers on the front in the normal way or do I need to go into the workshop menu and put the car into "brake change" mode? I know it's more complicated when you are doing the rears with the electronic parking brake but TBH I would have just ploughed ahead with the fronts if I had not seen an online post suggesting I need to do something different even on the fronts.

Discs are ok so it's just pads this time.

Any advice welcome please.

 

[onefortheroad]

When I did my 4 pot CLS calipers I just pushed them back as normal. What I did notice though , when you push one in , another would push out . You just set them so the pistons clear the new pads enough,to get the caliper back on.

 

[bembo449]

if you gently lever the pad back with a flat blade screw driver then you can use the old pad to press the pistons all the way home easily

 

[merk350]

I used the old pad turned over and just compressed the piston with a g clamp.Worked fine.

 

[howarddavidp]

Hello,

Dave from the US here, and I have a R231 SL400 of 2015 in Alpine White.

The front pads are easy, as you don;t have the remove the calipers, just knock out the 2 pins per side with a hammer and a nail or punch if you have one. Amazon sells a really nice Benz pin remover pin for $10 USD, it works nice.

For the front calipers pushing back the pistons, you can push one side in and put the new or old pad in to hold the piston back, then push with anything long, even a long screwdriver, the pistons on the other side. The move really easy, I could almost push them by hand on my car. So push them back on the inside all the way, put in your new pad and then push the outside all the way back to insert the outer pad.

The rear is a little more tricky, but not difficult at all, just be patient. You have to watch the YouTube videos to get your car into the menu where you can retract the rear pistons, I think this has to do with the electronic e-brake. IT took me a few tries until I got to the menu, but it will eventually appear, and you tell the car to pull back the caliper pistons. Pads are easy at this point, repeat what you did up front and pop the pads in. Once everything is back together, go back to the menu and select the option that the new pads are in place, and it will put the piston back to the normal position.

I originally did not use the red brake grease, and they started to squeal after about a week. So, I took everything back apart and applied the red grease, and this fixed the issues. I am not sure all cars will do this, but mine typically made the noise only when I came to a complete stop. During normal driving and breaking there was no noise, only when I came to stop signs or parking did it ever make a noise.

I have a Youtube video that goes into details about doing this on the front, search for :

2015 SL400 R231 Front Brake Pads service and fix for break noise, squeaking, whining Break Quiet​

The only other issue I had was about 6 months later, one of my pins worked its way out about an inch or so. The car worked fine, but there was a grinding noise. IT took all of 2 minutes to tap the pin back in, and I order a new pin because there was a notch where the pin rubbed against the top of the rotor.

I have since drilled a hole for a cotter pin to prevent this from happening again, maybe overkill but easy enough for me to do.

Good luck with your breaks, I can say this car was easier that many others I have changed pads and rotors on, just watch the videos so you don't do more work than needed, like I did remove the whole caliper when not needed.

Cheers my UK mates, man I loved Wales when I visited earlier this year, I went to Bron Yr Aur and stayed in Mach, the most beautiful country I have seen in my life, anyone hiring, I am ready to emigrate!

David Paul Howard

 

[AMGeed]

^ Welcome to the forum David