Well after a long hiatus, I'm back to devoting some time to my mach and the one thing that has drove me nuts over the years of driving is the lackluster brakes. The fronts were granadas and the rears were stock drums, and a leaky rear wheel cylinder put me over the edge and decided to convert my brakes. I first did the Mustang Steve rear disc conversion using 2015-18 Mustang GT 13" rotors. The next step was to address the fronts, which I knew I wanted the 13.2" rotor from the 2010-14 GT but needed a caliper. I bought Wilwood Superlite calipers but the brake pads were so short that they were only covering half of the swept width of the rotor. I then stumbled upon some late model mustang guys using Brembo calipers from a Cadillac ATS on their 13" rotors, which got me thinking and decided to take the plunge. I started with disc brake spindles but to make a bracket would have required CNC, so luckily I had some drum spindles laying around that made it much easier. These brackets are modeled after what MustangSteve offers for other late model brake conversions, but not the exact same since these are obviously Brembos that didn't come on Mustangs.
I'll note that I'm not quite finished with the conversion, as I'm still waiting on brake hoses but feel I'm far enough along to get this on here in case anyone else was interested. I don't have early model spindles, so this is geared toward 69/70 mustangs. I want to stress that brakes are a serious matter and can kill you or others if you aren't careful. While this is intended to help you make your own brackets, you really need to know what you are doing with fabrication and tolerances to get these calipers to fit the rotors. I'm providing PDFs of the brackets I made, but take no responsibility in any failures or misfitments. These are guides to get you going in the right direction and will take some adjustments and clearancing. I will also mention that it may be good, should you do this conversion, to transfer the PDF paper cutsheets onto a 3/8" thick cutting board or MDF and test fit before going through the headache of cutting 3/8" plate steel. I went through quite a few iterations and steel before I thought about cutting board. Through numerous iterations some changes were made along the way, and I believe the PDF is my last iteration but would help to try it with easier-to-cut plastic first. There is a chance I didn't get all the mods into the CAD file. I will also note that the bracket shim I specify is 1/4" plate, but you will need to determine actual thickness and adjust accordingly so that the caliper is centered on the rotor. One final thought in fabrication, the Caddy Brembos are designed for 12.6" rotors and these are 13.2" so the arc is a bit sharper and you'll want to locate the caliper onto the rotor so that the brake pads are recessed enough onto the rotor but not so much that the caliper is touching the rotor. This was the biggest headache for me and finally just clamped the undrilled caliper bracket to the spindle bracket in the exact location and then used transfer punches to mark the hole location. What I found was that the bracket that fit on one side resulted in the caliper touching the rotor on the other side, thus locating/clamping before drilling holes.
Parts list for me thus far:
NEW Brembo Calipers - 2013-19 Cadillac ATS from Rock Auto (no core charge) = $125 each
Caliper paint & clear plus vinyl decals from ebay = $30
13.2" rotors for 2010-14 Mustang GT - Powerstop AR85144XPR from Rock Auto = $133/pair
Steel plates - 3/8" brackets and 1/4" shim = $25
Brake Pads, Pins and Clips - I went with Power Stop Carbon Fiber Z23-1001 = $43
Bolts, washers, and nuts - I used flange bolts from Menards. Mix of 14mmx35 metric for calipers, 1/2-13 x 1 1/2 for caliper bracket-to-spindle bracket, and some 3/8" bolts for spindle-to-spindle bracket = $15ish
Drum brake spindles and hubs (replaced inner and outer pairs of hub bearings and seals = $50)
Stainless brake hoses - I went with Inline Tube's 18" long with 3/16 brake line fitting and 10mm banjo bolt fitting = $24/ea
GM 10mm banjo bolts and crush washers - $10
If going with new rear discs, I replaced my disc/drum distribution block with a tee on the fronts and wilwood adjustable prop valve for the rears (260-10922 for $45). I fabricated my own stainless lines since the stock ones won't work in that configuration without some tedious rebending.
I am reusing my stock disc/drum M/C on my stock booster. I confirmed no residual valves on this one and the smaller drum bowl isn't an issue for me on a non-daily driver
So all in, I'm at $650 which is about half of most aftermarket 13" rotor packages but there was a ton of time involved for me to develop the brackets and dealing with the sandblasting and painting of parts.
Now for the pictures!
What I started with:
Looks so tiny with those 17" wheels. Those rotors were barely larger than the wheel hub!
Mocking up brackets with the Caddy calipers and rotors. I didn't get any pics of the white cutting board that I used. A bit flimsy to get true measurements for shims, but helpful in verifying bolt hole locations and overall fitment. Also note the spread of the caliper bolts puts them close to the spindle arms, which a socket barely fits to tighten them. One way around that is to put the caliper at the front, but I figured that might look odd (even though its done on some cars)
Mounted to wheel to verify clearances. Don't worry, that Caddy emblem will get painted over:
Fitment now verified, so then comes paint and install (dont' forget the Loctite and torque specs!):