Another shot of my 13" PBR brakes, after a day at Laguna Seca in October 1996. Notice the rusty-looking discoloration at the leading edge of the anchor bracket. One of the bolts holding the bracket to the spindle loosened up, and allowed the bracket to come into contact with the rotor. It got very hot, as you can see. There is something else wrong with this picture. If you're familiar with PBR calipers, you might be able to spot it. Hint: look at the trailing edge of the caliper.

Give up? The pad guide pin is missing. It's a pin that fits between the pads and the anchor bracket, thereby retaining the pads in the bracket. The caliper is attached to the pads, and thus remains in place as long as the pads are properly retained in the anchor bracket. The pin is held in place by an E-clip, which probably isn't the greatest way to do it. Near the end of the day, that E-clip abandoned ship, leaving the pin free to slide out of the anchor bracket. During the last few laps, I got two or three random clunks as I went around right-hand corners. Because it happened only a couple of times, and didn't seem to happen with any kind of consistency, I thought perhaps I was running over something on the track. As it turned out, the guide pin had come loose and backed out far enough to catch the spokes on the wheel. The clunks were the sound of the wheel hitting the pin. Eventually, the wheel caught the pin and ripped it out (never to be seen again). I discovered this while braking for the Corkscrew. The driver's side caliper popped up, and I was rewarded with suddenly whacked-out brakes and horrible grinding noises. I barely made the corner, and I pitted immediately. The caliper and bracket have been replaced. The new caliper is a Corvette PBR caliper, which is essentially the same as the Cobra PBR caliper, but looks different and costs quite a bit less. I don't care how it looks, so that's fine with me.

After having been burned, I was reluctant to use E-clips again. I drilled a 1/16" hole in each pad guide pin, and I now use a cotter pin to retain the pin. There's a lot of heat and vibration down there, so I feel more comfortable having purely mechanical retention.

Some details: the 1/16" hole is drilled through the groove in the pad guide pin that was originally used for the E-clip, perpendicular to the axis of the pin.

I didn't have a jig, so I made one from a block of wood. I drilled a hole large enough for the pad guide pin to go through. Then I carefully drilled a 1/16" hole in the wood that intersected the first hole perpendicular to it and bisecting it. This took several attempts before I was satisfied that I had a straight hole. I pulled the bit out, put the pad guide pin in, and pushed the bit back down and slid the pad guide pin until I felt the bit catch the c-clip groove. Then I drilled the hole in the pin.

When you install the pad guide pin, use the washer that was originally used with the E-clip, then insert the cotter pin to hold everything in place. I may change to safety wire, but cotter pins work fine.

As a bonus, it's easier to remove/replace the pin with the cotter pins. I just cut the cotter pin off when I want to take out the pad guide pin. It's easier to insert the cotter pin and spread the legs than to try to install the E-clip, which always tended to pop loose and go flying into a remote corner of the garage.

Regardless of whether you use c-clips or cotter pins, mount the pad anchor pin with the c-clip/cotter pin on the outboard side. Easier to work on, and you can check it at a glance.