Brake upgrade W123 to W126 (humor me and read it please 500E guys)
 

W123 coupe 1983 to w126 560SEC bendix brakes.

I am going to do this upgrade. Has anyone done it? If not, Ill document it real good.

I am going to do new wheel bearings, new seals, rebuild the calipers, put it all back together with new bolts and caliper bolt locks and new hoses.

I got Ate Power discs which look sharp.

I got Mercedes Benz brake pads, but I am thinking of getting some porterfield pads, if some of you guys are interested in a porterfield group buy email me and Ill start a thread.

So any comments, suggestions, approval?

Let me know

I did that mod on my 1981 280E. You will need the brake backing plates as well. That mod works quite well.

I used 1991 560SEL Bendix Brake calipers (rebuilt them)

I actually got Zimmerman cross drilled rotors (300mmx28mm)

Changed wheel bearings, etc.

I just took off the dust shield backing plate, btw what are they for anyway?

Im looking to get ATE calipers to match, but for now Im not too worried, I may get dust sheilds if someone has some good advise.

The rear brake dust plate is an air scoop to cool the brakes, it is a smart idea to modify them so they will fit on the car and help with the cooling.

I installed front spindles from a 90 300sel complete with backing plates, hubs and larger discs and bendix calipers. The hubs are differrent for larger vented rotors. I also installed the later calipres on the rear also.

1981 30tdt

The hubs are different, but they will work from the w123 to bolt a w126 disc up to. Do you like the bigger rear brakes as well?

I just painted them black with G2 caliper painting system available from www.wheelskin.com I think that the red would have looked nice, but maybe too ricey, so that is why I did black. I will have picture by the end of the week.

lots of questions...
 

So, the "backing plate" is just the sheet metal behind the brake rotor, correct? Are these necessary to swap when using pre-1986 calipers/rotors? Those cars mostly came with 14" bundts, so wouldn't they also have the same backing plates as the 123s?

I just came home with front calipers from a 1982 300SD at the junkyard, but it was resting on the rotors/backing plates, so the plates were smashed. Also, are the rear rotors the same size as 123's? They appeared as the same diameter and I ran out of time so I didn't grab them.

What are the dimension differences on the small/large rotors for the 126s?

Thanks!

Backing plates are behind the disc. Most BBK (big brake kit) companies suggest not having backing plates, but I did put them on my car, when I had the hub off.

the early 126 brakes bolt onto the 123. he must have done late 126 brakes to have needed to change the spindles.

i believe all 126 rear brakes are the same as 123.

tom w

Cool, I'm all ready then at least for the "early 126 upgrade". Still curious though about the rotor sizes on the 126s. The 123 FSM gives diameter dimensions, but not the 126 FSM.

Well my calipers are Bendix from a 1991 560SEL, the rotors are 300mm diameter. And they bolted up to my hubs. I dont know where this early late info came from.

the early ones are same diameter, just thicker because vented. power is the same but fade resistance should be better. also not as likely to warp.

tom w

Earlier is better? I'm confused...

Where can I find slotted rotors? I found Zimmermann cross-drilled front and rear rotors at the Buy Parts link (Phil) and also from Rusty (***************), but I've heard slotted is better. Any suggestions about whether I should use slotted/x-drilled?

Thanks!

I've been wanting to do this mod as well. My brakes can get smoking hot after a hard 60-0 stop.