• April 10, 2016
• By: Steve

I noticed that the driver’s side rear pad was gouging into the rotor something fierce.  I hadn’t noticed any screeching but the signs were there.  Anyway, I took the caliper and pads off and the rotors/pads were indeed perished with the top rivet doing the damage.  I went to Advance Auto and they sold me the vented rotors and pads, which were Carquest Wearever part #GNAD637. It said they were direct fit for the 96 Cobra. I also rented the caliper piston tool to make sure I was able to screw the piston into the bore properly.

I disassembled everything and mounted the rotors and then the caliper mounting bracket.  I used the brake tool and I screwed the piston into the bore on both sides.  I put the new pads in place and the caliper wouldn’t fit over the pads. I tried cranking the pistons in further but they were in as deep as I could get them as far as I can tell. I did a little reading online and saw that there are different thickness pads for GT (16.8mm) and Cobra (14.9mm) due to the solid GT rotor and thicker vented Cobra rotor. I took the pads back to Advance Auto and asked them to verify that it was right and they saw the same part # was specified for GT and Cobra. Their site even said they were 14.9mm. I asked them to measure them with a dial caliper to make sure they really are 14.9mm and they didn’t have one.  At this point I didn’t know what to believe since I was sure I had the pistons screwed in all the way and they still didn’t fit.  I don’t have a definitive answer on whether they were really wrong for my car.

I ended up returning the pads and going to O’Reilly Auto. Their system listed two different part numbers for their BrakeBest line. C627 was for GT (16.8mm) and C627A (14.9mm) for Cobra with vented rotors. That made me feel better that their system definitely differentiated the two part numbers so I had them order me the correct ones.  I also realized that I had basically ruined the caliper dust boots by not lubricating them and keeping an eye on them while screwing the pistons in.  Yes, I mangled them because I kept turning them thinking I had to so the pads would fit.  I ended up buying two reman calipers from Autozone because I just didn’t want to mess with rebuilding them myself.   I guess I will be doing a full brake system flush/bleed as well, but it is due for one anyway.

Update 4/14/2016:

The pads came in today so I installed them and magically the new calipers fit over the discs.  I decided to bleed the brake system so with a little help I was able to get that done.  All in all I had another two hours in it since I had to install the reman calipers and bleed the system fully.