Greetings. I've a 2013 SL550, and, yes, it's my own bloody fault, but I screwed up the brake change I did on the left rear. Oh well, three out of four ain't bad.
Except when there is a fluid leak coming from the caliper. Which probably is bad as I would like the car to stop upon request, which I suspect is less likely the more fluid leaks out. So I guess I have to fix it.

Bottom line, I popped out the piston during the change. Long story, don't ask. I'm already beating myself up over it. I suspect that I either damaged, or just plain missed a seal putting it back in. Of course, being such a relatively new car, and one of the few folks who (a) own an R231 which is out of warranty so we don't mind doing our own work, (b) am willing to have a crack at it anyway, it seems that there is a very distinct lack of guidance online of what the thing is supposed to look like when put together correctly, and I have no intention of pulling the other one apart just to check for comparison.

Ideally, I'd just like to pull it apart again, buy some seals, reinsert everything (correctly) and profit, but compared to most 'how to' videos I've seen online, there seem to be a few more seals and parts in the repair kits I can find. An exploded diagram would be very helpful, if anyone happens to have one to hand. Otherwise, I have to assume the only seals are the square ring for the piston before the dust boot, one for the bleed valve, and one for the input line?

Backup plan seems to be to simply buy a caliper assembly which I presume has all the seals and parts installed. I show that as part no 2314230981 for about $300 from https://mercedespartscenter.com/parts/2017/Mercedes-Benz/SL550/Base?siteid=215720&vehicleid=491058&diagram=576368 5 which would require disconnecting the fluid line, unbolting the actuator, and then simply re-bolting the actuator back into the new caliper and then putting everything back together again. Or am I missing some really critical and difficult step in this which would make this a $300 fool's errand and thus a terrible backup plan?

Opinions and advice appreciated.

 

Are you familiar with how braking systems work? Your brakes are the monoblock style, so the number of seals and pistons increase. The parts are also more expensive.

Is it leaking from the banjo bolt? the piston seal? With the current information you will likely need to replace a seal and bleed the system.

 

oops you said rear left, thought i read front left. thats the floating caliper kind. should be easy to fix.