Front Rotor Assembly

This is part two of three parts.

As mentioned earlier, my used parts showed up with only the front rotor hats since the discs were worn out. Brembo offers a choice of either cross-drilled or slotted discs for replacements. Since I had useable drilled rear rotors with about 80% of their wear limit remaining, it was an easy decision to acquire matching front drilled discs:



Here’s a shot of the inner side of the replacement disc:



The disc mounts to the rotor hat using a spring loaded bobbin system. This gives the disc the ability to float and adjust to the pressure from the caliper pistons. Here’s a front side shot of the bare hat:



And here’s the inward side of the bare hat:



Brembo requires that a new hardware installation kit be used each time a disc is replaced. I’m no engineer, but I assume this is likely due to metal fatigue of the old parts as a result of heat-cycling and resistance loading and unloading. Anyway, since it’s my life I’m dealing with, I opted to purchase the required two new hardware kits. A kit as delivered looks like this:



The first step of the rebuild is to install the new hat fastener liners. Here’s a shot of the hat with the new liners to the side before installation. The liners slide into the openings on the hat:



Here’s a shot with the first liner installed:



Here’s one of the hat’s with all liners installed:



The next step is to insert the bobbins into the liners. Here’s a shot of the hat with all liners installed, with the bobbins to the side:



Here’s the hat with the first bobbin installed. The actual bolt that attaches the disc to the hat is inserted through the bobbin:



This picture show the hat, now assembled with all liners and bobbins in place:



The last step before the hat can be bolted to the disc is to position the springs onto the bobbins. Here’s a picture of the bobbin spring:



Here’s a picture of the disc awaiting installation of the springs:



And here’s a picture of the spring fitted to the bobbin on the hat:



The next step is to carefully fit the assembled hat to the disc in order to be able to install the attaching bolts. Here’s a shot of the hat fitted onto the disc, with the attaching hardware to the side:



Here’s a shot of the assembled hat placed in position on the disc:




This next shot shows all of the attaching hardware in place, but before each fastener has been torqued to specification:



Here’s a close-up of a bobbin and spring that has been torqued to specification:



This shows the outer side of the rotor assembly with all fasteners torqued to correct specification:



And here’s what the inner side of the completed rotor assembly looks like:



At this point, the front rotor assemblies are ready to be installed on the car.

 

How much does Brembo charge just for the discs and the hardware?

 

Also, does anyone know if a rebuild kit such as this one exists for the AMG floating rotors?

Seems like it would be cheaper to rebuild than to pay $800/rotor...