BMW E46 Brake Line Relocation Install Guides
BMW E46 with OEMC (CB-E46-OEMC)
1. We always recommend starting the installation by mounting the Bias Valve supplied with the kit. This will be mounted using one of the studs/bolts that secures the Brake Master Cylinder to the Brake Booster. We typically will use the stud/bolt closest to the passenger side of the vehicle or underneath the Brake Master Cylinder depending on the application.
2. The first thing that we need to do is split the front brake output on the Master Cylinder. To do this you will want to thread one of the 12mm to 3an Adapter Fittings into that front port on the Master Cylinder. The T Fitting will then be connected to that Adapter Fitting and will be oriented parallel to the Master Cylinder.
3. Using the roughly 17" line with the Chase Bays label on it connect the female 90˚ Fitting to the front side of the T Fitting on the Master Cylinder. The other end of the brake line will then go down and be routed through the hole at the bottom of the strut tower to the driver fenderwell where it will connect to that Fenderwell Brake Line.
4. The longest line in the kit will be connected to the rear side of the T Fitting on the Master Cylinder using the female 90˚ Fitting. The other end of that line will then be routed along the firewall and will go through the hole at the bottom of the strut tower on the passenger side where it will then connect to the passenger Fenderwell Brake Line.
5. Now, you will thread the second 12mm to 3an Adapter Fitting into the rear port on the Master Cylinder. The shorter 6" brake line with 90˚ Fittings at either end will connect to the Adapter Fitting. The other end fo that line will then go underneath the Master Cylinder and will connect to the "in" fitting on the Bias Valve.
6. The last line in the kit will then be connected to the Bias Valve "out" Fitting using the 90˚ Fitting on the brake line. The F Fitting supplied with the kit will be connected to the OE rear hard brake lines that were previously connected to the ABS block. You do not have to but, we like to trim back those hardlines for a little cleaner look. I included a photo showing where we trim those lines back to. Once the F Fitting is connected to those hardlines you will then connect the straight fitting from that last brake line to the male side of the F Fitting.
7. Now that everything is connected you will need to bleed each caliper, we suggest doing this with the Bias Valve knob all the way out (to the left) to give the most flow to the rear calipers. You can use a pressure or vacuum bleeder but, we have gotten the best results by using the two person method having one person pumping the pedal and another bleeding air at the caliper. You will want to start at the caliper furthest away from the master cylinder (passenger rear) and work your way to the closest caliper (driver front).
BMW E46 with Single Piston Brake Booster Delete (CB-E46-BBE)
1. We recommend having the ABS module (if applicable) removed and the Brake Booster Eliminator and Bias Valve installed before connecting the lines in this Brake Line Relocation. To install the BBE and Bias Valve, follow the steps below. If you already have these products installed, continue to step 2.
Brake Booster Eliminator Installation:
- Disconnect the brake lines at the master cylinder/abs module and remove from the engine bay.
- Install the BBE through the holes in the firewall where the OE Master Cylinder/Brake Booster was located and secure it using the 4x M8 nuts supplied with the BBE.
For the E46 Brake Booster Eliminator you have to use the stock "clevis". The design of the pedal doesn't allow for a normal style clevis. You will cut the clevis off of the original booster and then weld it to the included coupling nut. That will thread onto the master cylinder rod and then connect to the pedal just like the original.
- Tighten the 5/16 x 24 nut on the Master Cylinder rod against the clevis to keep it from moving.
- We recommend bench bleeding the BBE Master Cylinder prior to connecting the Bias Valve. This is easiest done by securing one of the brake lines in your Brake Line Relocation Kit to the 3an banjo adapter on the Master Cylinder and putting the other end of the line in the Brake Reservoir.
- Fill up the reservoir with brake fluid and begin pumping the pedal, making sure that the free end of the Brake Line is completely submerged in brake fluid.
- Continue pumping the pedal for a few minutes until you can not see any bubbles coming out of the Brake Line in the reservoir. Once there are no more bubbles you're good to go!
Bias Valve Installation:
- Remove the nut securing the bottom of the BBE Master Cylinder to the mounting plate and slide the Bias Valve bracket over the stud so that it is hanging. Thread the nut back on the stud and tighten it to secure the Bias Valve.
- Using the Stainless Steel Hard Brake Line supplied with the Bias Valve, connect it from the -3an Banjo Adapter on the BBE Master Cylinder to the "in" fitting on the Bias Valve.
2. The first line will be the driver side brake line. It is the middle length line in the kit with a 90 on each end. The female 90 will connect to the drivers side of the Bias Valve T fitting and the male connects to the driver side fenderwell line.
3. The longest line will be the passenger line. It has a 90 on each end as well. The female end connects to the passenger side of the Bias Valve T fitting and the male end connects to the passenger side fenderwell line.
4. The shortest line is the rear line which runs from the OUT fitting on the Bias Valve to the F-fitting that will attach to both of your rear hardlines.
Now that everything is connected you will need to bleed each caliper, we suggest doing this with the Bias Valve knob all the way out (to the left) to give the most flow to the rear calipers. We have gotten the best results by using the two person method having one person pumping the pedal and another bleeding air at the caliper. You will want to start at the caliper furthest away from the master cylinder (passenger rear) and work your way to the closest caliper (driver front).