Why is the driver's side rear brake caliper on a 4 wheel drive used on the rear passenger side on a 2 wheel drive vehicle? Why not use the same mounting location for both 2 wheel drive and 4 wheel drive? Either both front or both rear mounted. Are both positions equally effective? If so, to make it really simple, why not front mounted on one side and rear mounted on the other side? One part fits both sides. Wouldn't that make things a lot simpler? Please enlighten me.


Tanks in advance for your insight.


Larry

 

bleeder screw would be in the wrong location
needs to be upward of the piston

 

What I am trying to figure out is why two different mounting locations for the calipers depending on whether it is 2 wheel drive or 4 wheel drive. There have been many posts on this forum where people couldn't bleed the air out of the brake system after installing a new caliper only to realize that they had the wrong caliper because they didn't specify for 4 wheel drive and got the one for the 2 wheel drive and finally realized you can't get the air out of the system by bleeding below the piston. If you look at the driver's side rear caliper on a 4 wheel drive, the bleeder is to the right end/top of the caliper. The bleeder is to the left end of the caliper if it is 2 wheel drive. Why? Why not use the same caliper for both 2 wheel drive and 4 wheel drive?

 

Think I found the answer to my question. I have a ZR2 which has the 8.5" rear end. The regular Blazers have a different rear end. So probably just different caliper mounting positions on the two different axles. At least they use the same calipers on both axles. ZR2's can be fun to find parts for sometimes.