How-To: Install Secondary Caliper Brackets

How-To: Install Dual Caliper Bracket to your E30 Chassis

Overview: 

• Part Name: E30 Rear Dual Caliper Mount Weld-On Brackets
• Part Number: K0025
• Part Page: Link
• Difficulty Level: 8

Tools Required:

• Welder (preferably tig)
• Wire wheel/brush to prep surfaces for welding
• Acetone
• Jack and jack stands
• Caliper for measuring

How to Install Your E30 Dual Caliper Brackets

Properly positioning and welding the dual caliper brackets to the E30 rear knuckles is the most important step of the entire secondary caliper installation process. If done improperly it will result in the hydro e-brake will not perform as it should and improper pad wear.  

The entire hydro e-brake system should be installed before you begin this process. This means everything; the handbrake should be mounted, hydraulics for the secondary caliper ran and plumbed, and all fluids bled to remove any air from the system.

1. Jack up your E30 on a level surface and support it on jack stands.  Remove the rear wheels and use a couple of lug nuts to secure the rotor in place flush against the hub.
2. Thoroughly clean the surface of the rear knuckles were the brackets will be welded.  Ideally, use drill mounted wire brushes and acetone to remove any rust, oil, and other contaminants from the area and get the surface down to the bare metal.  This preparation is crucial to getting a clean and high-strength weld that will not fail.  
3. Bolt the calipers and carriers to the brackets, and with the pads installed place them in the desired position on the rotors. The secondary caliper weld-on bracket should be sitting fairly flush against the knuckle
4. Have someone pull the handbrake and lock it with a bungee cord. This will be the engage the calipers and ensure equal pressure is applied to both pads against the rotor for optimal wear. This will hold the secondary caliper assembly in place while you tack weld the brackets to the rear knuckles. 
5. Before you tack weld the brackets take measurements to make sure they are mounted evenly.  Tack weld the brackets to the knuckles. It is best to do most of the welding with the brake engaged to firmly hold the assembly in place and prevent the bracket from moving around during the welding process.