So you’ve got your big shiny wheels with fancy sticky rubber that looks great from a distance.  Move closer and the bling from the wheels is diminished because of that crusty drum brake poking out.  Sure you can wire brush 40+ years of crud from the drum and paint it but nothing looks better and shows you mean business than 4 wheel disc brakes.  Not only are rear disc brakes a visual improvement, they also perform better than drums. 

In this article we’ll detail how to install our 11.65” Rear Disc Brake System Conversion onto a 66 Mustang.

Read on to see how simple this install is:

The first steps of the install are to get the car in the air and the wheels off.  We’d recommend jacking and using stands on the frame rails so the rear end hangs lower.  This will give you more clearance between the axle and rear frame rails.

Remove the brake fluid hard line from the back of the drum.  These can sometimes be stuck fast so go careful not to round off the soft fitting.  Use a flare wrench if it won’t budge.


The axle hard lines need to be modified later so we went ahead and removed them completely.  So fluid didn’t drip from the ‘T’ fitting we plugged them with some spare tube nuts that we welded closed the hole.

Next you’ll need to remove the outer drum to gain access to the parking brake cable connection and backing plate retaining bolts.  Remove the parking brake cables.  Rotate the axle around and use the hole in the axle flange to remove the 4 retaining bolts.

Pull the axle from the housing being careful not to drag it along and damage the axle seal.  Remove the drum backing plate from the axle housing.   If the axle seals and bearings are questionable, now would be a good time to replace them.

We used a die grinder with a cleaning pad to clean the crud from the end flange.

Now we can start the installation of the new parts.  First up, the billet aluminum end flange bracket.  This bracket features a series of holes so you can ‘clock’ the caliper position up or down to clear leaf springs etc.  We found that the 10 o’clock position passenger side and 2 o’clock driver’s side worked best for us.  This bracket is retained using the original backing plate ‘T’ bolts and nuts and features an integral bearing retaining design.  You can choose to remove the bearing and remove or cut off the stock retaining plate, or leave the bearing on and bolt the stock retainer on over the new bracket.  We chose the easy route and bolted it on over the new bracket.

To center the caliper on the rotor, we have to measure the axle standoff.  To do this we measured using dial calipers from the front face of the axle flange to the backside of the newly installed bracket.  We include a handy shim chart in with the instructions to aid in shim stack selection. 

Ours measured 2.485” on the passenger side and 2.5” driver’s side and the chart told us to use a .100” shim.  We inserted the shim between the end flange bracket and the intermediate bracket both sides of the car, put a dap of red Loctite on the bolt threads and installed the intermediate bracket.

To ensure the rotor is hub centric the kit includes a centering shim.  Slide this onto the axle.

This kit features the upgraded slotted, drilled and zinc washed rotors.  Slide the rotor onto the studs and to help hold it in place we loosely installed a lug nut onto one of the studs.

Next we installed the appropriate caliper making sure the bleed screw was up.  A dab of blue Loctite on the threads and torqued to 85ft-lbs helps keep the bolts secure.

The kit includes custom built parking brake cables.  To start the install of these we hook the correct end into the caliper and secure it with the supplied e-clip.

Using the factory parking brake cable clamps we route the cable along the underside of the car and click the ‘finger’ clamp on the other end of the cable into the factory bracket in the transmission tunnel.

Next we loosen the adjusting nut on the parking brake equalizer rod and overlap the new and old cable by 12”.  We cut the old cable and secured the new and old cable together using the supplied cable clamps.  Once the other side is installed we tightened the adjusting nut on the parking brake equalizer rod and tested the parking brake.

Now we move back to the rear end and install the supplied stainless steel braided brake flex hoses.  Start by measuring from the axle end flange 12” toward the center section, using the supplied hose clamp; secure the hose mounting bracket to the axle tube.  You could also choose to weld the bracket to your housing instead of using the clamp.

Secure the hose into the bracket with the brake line clip.

Attach the other end of the hose with the banjo bolt being sure to ‘sandwich’ the hose banjo fitting with the new crush washers.

Using our old hard line we trimmed off the section that used to run to the drum backing plate, double flared it and connected it to the new fitting on the flex line.

 

Once the hoses and hard lines are installed both sides, we checked for interference.  It is critical to ensure adequate clearance from bump stops, exhaust and shocks.  If we encountered any interference we’d have to loosen the banjo bolt and/or hose mounting brackets and move the hose before driving.

After a thorough brake bleeding and wiping the front/rear rotors down with brake cleaner to remove any greasy fingerprints, it was time for a test drive! The parking brake works way better than it ever did with drums and the rotor looks great behind a set of 17x8 American Racing Torq Thrust M wheels!