Brakes

Rear Brakes

During my quest to rid the M Roadster of rattles and squeaks it became obvious that the rear brake pad "anti-rattle" clips and any sound control compound or coating that had been applied to the back of the pads was not doing the job.  I'm also not a big fan of "drilled for aesthetics" rotors, so it was time for a complete rebuild and refresh of the rear anchors.  

 

It started like this:

Rear Brakes - Drilled Rotor.png

The parking brake shoes had seen better days; the parking brake had either been left engaged or had been poorly adjusted for a period of time, so time for new shoes:

Old vs. New Parking Brake Shoes

Old vs. New Parking Brake Shoes

Stripped

Stripped

The caliper bores and pistons looked great, no corrosion or unusual wear; a new set of seals and I was good to go:

Z3 M Roadster Rear Caliper Pads, Piston, Seals, and Hardware

Z3 M Roadster Rear Caliper Pads, Piston, Seals, and Hardware

Although I could have cleaned up the old caliper guide pins, new hardware seemed like a good idea; although BMW specifically recommends not lubricating the pins, at some point caliper grease had been smeared onto the old pins, which turned into sticky goo.

Z3 M Roadster Rear Caliper Pins

Z3 M Roadster Rear Caliper Pins

I considered going with stainless steel HEL motorcycle bleed screws, but with a little bit of thread seal / locker painted on the threads these aftermarket Carlson H9411 bleeders will be fine for my fair weather ride:

M7 X 1.0 X 32 Caliper Bleeder Screws

M7 X 1.0 X 32 Caliper Bleeder Screws

Beware, the small dowel pin, shown in the upper left corner of the parking brake hardware photo below can easily go missing. The pin fastens the parking brake cable to the actuating arm directing below it in the photo.

Z3 M Roadster Parking Brake Hardware

Z3 M Roadster Parking Brake Hardware

Stoptech and OEM rear brake hoses:

Stoptech and OEM rear brake hoses:

While I'm happy with the Stoptech hoses, they are not keyed for the chassis mounting brackets like the OEM hoses, and a washer is used to compensate.  It's my understanding the Centric and StopTech stainless braided brake hoses are the same parts, and use the same numbering system; StopTech is a high performance and racing brand from Centric Parts.  The rear set of Z3 M hoses are StopTech / Centric 950.34513.

StopTech vs. OEM Hose Ends

StopTech vs. OEM Hose Ends

Z3 M Roadster Rear Brake Hose Mount

Z3 M Roadster Rear Brake Hose Mount

I went with Centric OEM quality high carbon steel rotors. To avoid any pad break-in issues, I strongly suggest removing the anti-rust coating from the machined surfaces; scrub the pad contact area using an appropriate de-greasing solvent such as lacquer thinner or aerosol brake cleaner, then another scrub in hot soapy water:

Rotor Bath

Rotor Bath

New Parking Brake Shoes Installed

New Parking Brake Shoes Installed

After throughly cleaning the caliper castings I used VHT High Heat (550°F) "Cast Iron" finish engine paint to make the calipers pretty; the paint is holding up well a year later.   The rear brake wear sensor is located on the right side.  Wear sensors can be reused if they haven't been triggered by pad wear, but sensors are inexpensive, so I went with a new one.

Rear+Brakes-Reassembled.png

I went with ATE SL.6 DOT 4 brake fluid:

 
Left Rear Brake Rotor

Left Rear Brake Rotor

 
Right Rear Brake Rotor

Right Rear Brake Rotor

 
Genuine BMW Rear Brake Pads

Genuine BMW Rear Brake Pads

 
ATE Caliper Pin Bushing Kit

ATE Caliper Pin Bushing Kit

 
ATE Parking Brake Shoes

ATE Parking Brake Shoes

 
ATE Caliper Guide Pins

ATE Caliper Guide Pins

 
ATE Rear Caliper Seal Kit

ATE Rear Caliper Seal Kit

 
Rear Caliper Bleed Valve

Rear Caliper Bleed Valve

 
Bleed Valve Dust Cap

Bleed Valve Dust Cap

 
VHT High Heat Cast Iron Paint

VHT High Heat Cast Iron Paint

 
StopTech Rear Brake Hoses

StopTech Rear Brake Hoses

 
Rear Caliper Anti-rattle Clip

Rear Caliper Anti-rattle Clip

 
Rear Brake Pad Wear Sensor

Rear Brake Pad Wear Sensor

 
ATE SL.6 DOT 4 Brake Fluid

ATE SL.6 DOT 4 Brake Fluid

 
Motive Products Power Bleeder

Motive Products Power Bleeder

 
 
 
 
 
ATE SL.6 Brake Fluid

I'm mostly happy with the Schwaben pressure bleeder; my only gripe is that the supplied cap is somewhat off and doesn't smoothly thread onto the master cylinder reservoir, however I was able to  remedy the master cylinder cap issue:  Schwaben Pressure Brake Bleeder Saga 

I like using a pressure bleeder, but if I were in the market for a new one, I think I would go with the less expensive  and well-reviewed Motive Products 0100 European Power Bleeder.    

Schwaben Pressure Bleeder

Schwaben Pressure Bleeder

The annoying brake pad rattle is gone and no more crusty calipers or boy racer drilled rotors peeking through the Roadstars:

Sorted!

Sorted!

I used BMW, Centric / StopTech, and ATE parts for the rear brake rebuild, and have been pleased in most cases; I was not happy with the Centric low dust ceramic pads that I initially installed.  The Centric pads stopped great and the wheels stayed clean, unfortunately the pads were noisy, but oddly just when moving in reverse.  The Centric ceramic pads would often emit an annoying squeak / squeal when tapping the brakes while backing up, but were generally quiet during most driving conditions.  I switched to OEM flavor Texstar pads and no more noise issues, just a bit more brake dust; given a choice, I'll take dirty wheels over noisy brakes.