The following sequence can be used as an installation manual for the 83-164-6700 StopTech front big brake kit for the AWD models of the E90/E92 3-Series. Follow along as Dave Zeckhausen personally installs this 4-wheel big brake upgrade. We had the pleasure of installing kit# 001 and evaluating the design of the brake lines, which are different than those used on the RWD models. The new lines fit perfectly on the first try.
Stock front brakes behind 18" Mille Miglia HT3101 winter wheels.
The first step was to see if modification to the stock rotor dust shield would be required. Stock caliper has been removed and StopTech caliper bracket is held in place to see if there are clearance issues.
We temporarily bolted up the bracket and slid the StopTech 6-piston caliper onto the mounting studs. There was contact at each end of the caliper, so some trimming of the dust shield is required.
A small triangle of metal is cut away from the dust shield, just below the bracket, using a common pair of tin snips.
Similarly, a small piece is removed from above the bracket.
Now Dave Z. slides the caliper back on to check for clearance.
Perfect! There's plenty of clearance at both ends of the caliper. Now we can continue.
The stock caliper mounting bolts are used to hold the StopTech caliper adapter bracket in place. Bolts are torqued to factory specifications.
A wire brush is used to remove any rust from the hub. This ensures the new StopTech rotor assembly will sit flat, minimizing lateral runout.
The new StopTech AeroRotor/AeroHat assembly is installed. We opted for the optional zinc plating, since this car will never see track use and will be used as a winter car. The stock 6mm Allen rotor retaining screw is used to hold the assembly to the hub.
The StopTech ST-60 caliper slides onto the caliper bracket mounting studs.
Two washers and 1/2" Jet nuts are installed to hold the caliper in place. They are torqued to 35 lb-ft.
Pads are dropped into the caliper from above. These are the new StopTech Street Performance pads that now come standard on all StopTech big brake kits. Amazing pads! Low dust, no noise, rotor friendly, high friction level, and they can even be taken to the track and pushed HARD.
The ST-60 caliper stiffening bridge is held in place with four 5mm Allen bolts. It's a good idea to apply a light coating of anti-seize to the threads and the body of the bolts. I like Permatex brand.
Bridge in place on top of caliper and bolts being gently tightened. The official torque spec is 8-10 lb-ft. The bridge also doubles as a pad retaining device. To get the bolt holes to line up, you need to push it down with the palm of your hand.
Now it's time to route and install the brake lines. A banjo bolt and two crush washers are installed on the caliper side. The line is routed through the stock E90 bracket, and then into the chassis bracket to connect to the car's hard line. The line is installed in the shape of an "S" with equal amounts of slack on each side of the center bracket.
The original BMW spring clip that retained the factory rubber line is used on the StopTech line. However, to make it fit tightly, you should tweak the clip with needle nose pliers, giving it just a little more curvature.
The clip is shown installed. It clips over the StopTech fitting and a gentle tap with a small hammer moves it into it's final, secure position.
A quick bleed of the brakes and this side is completed!
Here's the original front caliper. Yuk!
The 18" Mille Miglia winter wheels easily clear the 6-piston StopTech calipers and 355x32mm rotors, with room to spare.
After a quick run around the block to bed in the brakes, the yellow zinc plating is gone from the swept portions of the rotors. But it remains everywhere else, protecting the iron rotors from harsh winter conditions, such as road salt and ice melting chemicals.
Now it's time to upgrade the rear brakes.
The 335i xDrive rear brake upgrade is identical to that of its RWD cousin. So we didn't document the installation step-by-step, since the StopTech instructions are quite comprehensive.
This is one of the easier rear brake kit installations we've done, since the factory dust shield does not have to be trimmed for the StopTech 345x28mm rotor assembly to clear.
The end result is a 2009 BMW 335i xDrive with astonishing brakes, more than able to keep up with the 400 horsepower and 400 lb-ft of torque supplied by this car's modified engine.
