2000+ BMW E39 M5 and 5-Series 355mm Rear Big Brake Upgrade ST-40 Caliper Installation

The most common cause of brake vibration is improper bed-in of pads and rotors, or improper pad selection for the specific driving environment. Rotor run-out may also cause vibration, but precision manufacturing and inspection typically mean that run-out is not an issue. Modern production methods ensure that the rotor run-out is within +/- 0.002” when installed on a StopTech aluminum hat, and it controls thickness variation to within 0.0003”. Under the most extreme conditions, any rotor may warp, but uneven pad deposition is a more typical cause of vibration. If the system is not properly bedded-in, or if street pads are run on an open track, uneven pad deposits will occur, causing an ever-worsening vibration. Failure to immediately address a pad deposition/vibration issue may lead to permanent damage of the rotors. Please read and understand the bed-in procedure included in this manual.

Wheel Spacers
Wheel spacers can provide extra clearance to the outer face of the caliper. This will also space out the entire wheel, widening the track width of the vehicle. Fender clearances should be checked on lowered cars, and longer lug studs or wheel bolts are usually required.

Note: The Wheel Industry Council has issued guidelines advising that wheel spacers not be used. It is the responsibility of the customer to ensure that wheel spacers are properly specified and installed.

Brake Noise
Certain brake pad compounds make more noise than others. Proper anti-squeal shim plates between the caliper pistons and backing plate of the pad help to reduce the problem. Anti-squeal lubricants are also available, to reduce some of the noise. The reality is that performance pads are more prone to brake squeal.

Caliper, Hat and Bracket Finish Disclaimer
Many wheel-cleaning solutions contain strong acids that may damage the finish on any caliper or aluminum anodized finish, especially the plating on the hardware. Check for adverse effects by trying a small amount of the cleaner in question on an inconspicuous area. Avoid over-spraying, and rinse cleaning solutions off as quickly as possible. StopTech is not liable for damage to calipers, hats or bracket finishes, due to corrosive chemical exposure.

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