brake hose or caliper

This is the problem iam having. My 97 explorer sport has been pulling to the right really bad the past month. Thought maybe its a alignment problem. today i noticed the front passenger rotor is groved bad. My thoughts are the caliper isnt releasing. I have been reading post about brake hose or caliper. How can you tell which one it is? I did notice when i changed my oil the other day my brake fluid was a little low (between min & max) i filled it up to max. Any suggestions?

You need to pull the wheel and check the pad wear. Did the pads wear evenly? Try compressing the caliper. If it compreeses easily, the hose is fine as is the caliper. If it's really difficult to compress, try again but this time open the bleeder screw. If it compresses easily with the bleeder open, the caliper is fine and the problem is likely the hose. Since you're going to have the system open, replace all the brake hoses and flush and bleed the system once.

-Rod

I have changed the pads, but have never bleed the system. How is that done?

There are a few ways to bleed the brakes. If you plan to do this by yourself, then I suggest you go the route of installing Speed Bleeders on each of the calipers in place of the stock bleeder screws. Speed Bleeders and their off-brand competitors incorporate a 1-way valve to make brake bleeding painless.

You could also go with a Mity-Vac or similar and do the one-person bleeding that way as well. This is a good route if you want one tool that can serve multiple purposes, but is not quite as easy as the speed bleeders.

I'm sure there are multiple pages on the Internet that explain how to bleed brakes, so I won't go into a lot of detail here. Essentially you want to start at the wheel farthest from the master cylinder and bleed the air out of that line, or bleed until fresh fluid comes out (depending on if you are bleeding or flushing the brake system). Then move the the next farthest, etc. Periodically check the fluid level in the master cylinder to make sure you don't run it dry.

If flushing the system, once you've got all the lines bled, take the vehicle out and cause the ABS to safely activate to get fresh fluid cycled through the ABS pump. You don't want that old fluid sitting in the pump corroding valves and passages.

-Rod