W205 c200 front brake upgrade

[Jalloy57]

Hi, Apologies if this has been discussed before. I have a W205 c200 which, while the brakes are ok, they don’t have real bite. I am considering upgrading to the 350e front calipers. There’s loads of material about upgrading to c63 stuff but that’s way beyond what I’m after. I’m running the std 17” wheels which I believe are also std on the c350e so could anyone confirm if the (blue) 4 pot calipers are a straight bolt-on swap with new discs ? btw what dia are these? I
would’ve thought this would be a fairly popular upgrade if it’s possible but can’t seem to find anything helpful. Appreciate any advice. Thankyou

 

[W1ghty]

What about just changing to a more aggressive pad (if that’s a thing )

 

[Jalloy57]

Hi, Apologies if this has been discussed before. I have a W205 c200 which, while the brakes are ok, they don’t have real bite. I am considering upgrading to the 350e front calipers. There’s loads of material about upgrading to c63 stuff but that’s way beyond what I’m after. I’m running the std 17” wheels which I believe are also std on the c350e so could anyone confirm if the (blue) 4 pot calipers are a straight bolt-on swap with new discs ? btw what dia are these? I
would’ve thought this would be a fairly popular upgrade if it’s possible but can’t seem to find anything helpful. Appreciate any advice. Thankyou

What about just changing to a more aggressive pad (if that’s a thing )Thanks W1ghty, it’s a thought but not sure my driving style warrants that kind of pad. Example last week…5 up doing 70ish on the motorway when seemingly for no reason traffic slows suddenly to near standstill….Bit of a heart-stopper. Thinking that calipers from higher performance version should provide greater bite just on odd occasions rather than uprated pads for more regular use but I’d welcome any advice from anyone who has these calipers.

 

[W1ghty]

When was the brake fluid last changed buddy ?

 

[Jalloy57]

Hi, Apologies if this has been discussed before. I have a W205 c200 which, while the brakes are ok, they don’t have real bite. I am considering upgrading to the 350e front calipers. There’s loads of material about upgrading to c63 stuff but that’s way beyond what I’m after. I’m running the std 17” wheels which I believe are also std on the c350e so could anyone confirm if the (blue) 4 pot calipers are a straight bolt-on swap with new discs ? btw what dia are these? I
would’ve thought this would be a fairly popular upgrade if it’s possible but can’t seem to find anything helpful. Appreciate any advice. Thankyou

What about just changing to a more aggressive pad (if that’s a thing )Thanks W1ghty, it’ a thought but not sure my driving style warrants that kind of pad. Example last week…5 up doing 70ish on the motorway when seemingly for no reason traffic slows suddenly to near standstill….Bit of a heart-stopper. Thinking that calipers from higher performance version should provide greater bite just on odd occasions rather than uprated pads for more regular use but I’d welcome any advice from anyone who has these calipers.

When was the brake fluid last changed buddy ?

3 wks ago, so brakes working normally, just want more grab than they are able to deliver.

 

[whitenemesis]

Braking is reliant on the tyre to road grip. If you can set the ABS off now you won't get better stopping power from bigger brakes. What you would get is more reliable repeated braking ability as the bigger brakes would dissipate heat better, great for track days.
TBH nothing to be gained in normal day to day driving by fitting bigger calipers.

 

[Bellow]

Braking is reliant on the tyre to road grip. If you can set the ABS off now you won't get better stopping power from bigger brakes.

And if you did (get more braking effort), then you'd be pushing the fronts (in this case) into locking and releasing before the rears had contributed as much as they could and more pedal pressure to get the maximum from the rears just exacerbates this - the net result of which is less braking. And, by biasing to the front, much more likely to lock the fronts on wet roads.

There's also the size of the master cylinder to be considered.

 

[Jalloy57]

Thankyou for your reply…All valid points but why would MB fit 4 pots to the 350e for instance? Is it simply the extra weight of the battery pack requires bigger brakes. Or is it just something visible to justify the extra £££ ?

 

[Fastcar155]

Hi , genuine MB pads ?

 

[Jalloy57]

Yep all std.

 

[Bellow]

Thankyou for your reply…All valid points but why would MB fit 4 pots to the 350e for instance? Is it simply the extra weight of the battery pack requires bigger brakes. Or is it just something visible to justify the extra £££ ?

I honestly wouldn't begin to guess why - all your suggestions (especially the last one!) are possible. What we can be certain of though is that by correctly sizing/resizing the master cylinder they will have endowed the car with the correct braking balance front to rear and achieved the desired balance of pedal effort vs travel.
Even why 4 pots are chosen isn't obvious. Maybe, the greater piston area gives more force on the pads (at the expense of pedal travel) or maybe the piston area(s) are the same but the twinned pistons permit better transmission of the force to the pads which also allows longer, slimmer pads to be used which can be deployed at a greater radius on the disc's surface. There's more to brakes than just 'bigger'.

 

[Jalloy57]

Yep good points. Had a Jag some time ago. On their forum anything you were thinking about someone would have tried it. I was hoping the same would apply here. Surely I’m not the only dude to have considered this ? Just interested to get the views of anyone who had….Worth it or not/straight swap or problems to consider etc.If it were the C63 brake conversion there’s a whole avalanche of stuff out there about that. Given that mainstream manufacturers understandably like commonality across platforms I wouldn’t expect any particular issues. Guess it’s a case of looking up the part no’s to see if they’re common to both models.

 

[Bellow]

On an American forum I visit there are endless threads from people who have changed brake components expecting better results and are posting asking why their braking is worse than before. Invariably the answer is that they've created a mis-matched system. The advice is if changing one component, change all components. The match between calipers and master cylinder being the critical one but the rears are also affected by master cylinder changes.
Brakes are also fashion items with the associated bragging rights - whether they are actually deployed to anywhere beyond what the standard system is capable of is debatable (but likely to be fiercely defended!). I saw a lovely drilled and grooved disc set-up the other day. It was on the electric pallet truck in the back of a delivery truck. Enough said.

In America they have a system for grading pads according to bite etc. Denoted by double upper case letters, I don't know much about it other than different pads wear discs at different rates. There'll be info on the 'net about it. Maybe scope there for you to get that initial bite you're after.

 

[Jalloy57]

Thankyou, interesting. But I’m trying to establish if there is any difference other than the front caliper and disc size, ie same master cylinder/servo, same rear caliper, biasing or any other unforeseen issues.(Trying not to overthink this). Are there any MB mechanics out there who routinely work on these ? They must surely know the answer ? ?

 

[Bellow]

Parts list probably your best bet and someone here should be able to point you in the direction of MB's one.
Just had a quick look on Rockauto and the only master cylinder listed for a 2015 C63 is also listed (among others) for a C250 so maybe more commonality in MCs than I expected - and the combined piston areas of different calipers closer than duplication of pistons suggests.

 

[whitenemesis]

I'll drag out the age-old caveat, especially relevant to this type of modification...
What would your insurer think to you doing this?

 

[Jalloy57]

That’s on the ‘to do’ list but as I’m not increasing performance and using std MB parts I’d be surprised if there’s trouble. Same insurer gave me their blessing when I switched std alloys for staggered AMG items on a W204 220Cdi.