Rear Disk Brakes
|
|
|
|
|
|
|
|
|
|
|
|
My goal was to create my own rear disk kit. I did not want to spend $600 for a kit. I don't want to call up Willwood or Baer for a new set of rotors or brake pads. I don’t want to re-drill rotors each time I do a brake job. After the initial machine work, every brake part I have is common at part stores across America. I also did not take the effort to install an emergency brake. Living in Michigan winters, brake cables rust out in months, I’ve never had a working emergency brake, nor needed one. I understand my ignorance, and that some states require this safety devise for vehicle inspections.
PLEASE TAKE YOUR OWN MEASUREMENTS, YOURS COULD BE DIFFERENT. I WROTE DOWN APROXIMATE MEASUREMENTS; DO NOT ASSUME YOUR AXLE IS JUST LIKE MY AXLE!
The Jeep rotors already have the same 5X5.5 lug pattern. However they do not fit over the axle. Machining the outside diameter down to ~ 6.25” fit inside the rotor. At the same time I machined the outside face of the axle flange so it is perfectly straight. The rotor and wheel might have slight wobble in/out if you don't do this!
Next we had the issue of the rotor wheel stud holes being too large. The rotor must be centered on the wheel studs or it will flop forward / backward violently when I stabbed the brakes. The rotor also must be centered on the axle or it will be out of balance when rotating. We made spacers to fill the void between the rotors and wheel studs. My rough measurements were 5/8” OD, 1/2" ID, 3/8” wide; however they are almost a press fit inside the rotors, and over the studs. The tighter you get the rotor on the studs the better the outcome.
99% of the caliper mounts in the world are designed for GM calipers. So I picked out a ¼” thick caliper bracket that welded on a 3” axle tube, which used GM calipers with mounting holes 3.5” between centers. I choose the S-10 calipers because they were used in many other expensive kits on the market. The GM calipers typically used for rear disk brake conversions are a floating style, which slide back and forth over time as the rotor wears. So you can't use solid brake line and expect it to last a long time with the caliper moving. Most rear disk swaps retain the stock center brake hose, and then add smaller hoses at the ends to the calipers. Instead I'm using the 4X4 S-10 hoses, which are about 15in long, and running brake hoses from the frame down to each caliper. They do come with a fancy mounting tab in the middle of the hose. I didn’t need it, so I cut it off careful not to cut or melt the hose. My truck already had holes in the frame perfect for mounting the hoses. Had to buy a nut to clamp the hose to the frame rail. I don't have a lift on the rear of the truck, but still have ~ 6in of brake hose travel left. For more travel the hoses could be mounted under the frame.
Its stops even quicker once I get them warmed up, NO BRAKE FADE! I went to the drag stip on a slow day and was able to make 8 passes in under 20 minutes without brake fade!