Does anyone know what the difference between the s12w (90-91) caliper and the s13w (92-95) caliper is. I got a screemin deal on a pair of s12w's and I'm hopping they will work.
I believe that the earlier ones are 35mm pistons vs the 40mm pistons on the later ones. But on the earlier ones you don't have to grind the calipers to clear the wheels (at least I didn't).
Would the reduced piston size affect stopping performance? I'm still planning on swapping the MC and doing this swap, but it would be great to be able to install a caliper without any cutting...
The reduced piston size would increase the system pressure, needed to exert the same force on the pads. You get less fine control and have to push harder.
There is a difference. I had the 92-96 rebuild kit and it will not work on the earlier ones. We were measuring everything standard at the parts store as I'm not sure the locals have heard of the metric system... but I think it worked out to 35 and 40mm.
I am running the earlier ones on my rig and the stopping power is great. I did not have to grind the calipers to clear the stock wheels. There was only minor cutting to the dust sheild.
This mod is really a no-brainer, i had to do a little grinding but thats probably just because im running rockcrawler wheels. As the pads have broken in a little bit ive really felt a difference in the brake performance, instead of feeling like the brakes were maxing out that last 20 feet of a stop i feel like ive got plenty of force to haul the truck down. I havent really hit em hard enough to lock the tires but there is enough force to make me have to pay attention to my steering when i get on the brakes hard, it wants to pull to the side when i get on the pedal hard.
Oh, and a little trick i found helpful is to use a golf tee to stuff in the end of the brake lines to keep the fluid from dripping out, i put in the master cylinder before the new calipers and the tees kept my fresh fluid from just draining out onto the floor.
Hmm, i would think that you couldnt tell a difference between the two, and chris was saying the earlier calipers are a little smaller so if youre freaked out by grinding then they might be a better bet for you.
What kind of master cylinder are you planning on running?
Yeah, i was working on mine with a big ass grinder and it never even heated up the casting, its stout as s***. I was trying to find a good junkyard deal but ran out of time and ended up getting NAPA remans.
