One Seized(?) Caliper and leaking brake fluid

[LVExp]

Thank you to everyone that gave me advice on my header problems a few months back. I have spent the time since saving up the money to do the exhaust system from the headers back (NE truck and everything is rusted out) and taking stock of any other issues to see if it is time to throw in the towel or not.

I just changed the front break pads and oil in preparation of a long trip (650 miles round trip) and found that the passanger side front pads were worn on evenly. The inside pad was alot more worn then the outside. The calipers looked fine and functioned properly when tested. So i replaced the pads and made a mental note to keep an eye on it.

Well on the way back from our trip i was driving behind my wife who was driving my X and there were intermittent small puffs of white smoke. Having already blown a brand new tire on the car i was driving at 80mph and almost wrecking and knowing i needed to replace the ring around the oil drain plug i thought it was a little oil leaking and hitting the Cat and we were almost home (40 miles).

Today (the next day) I took a look and it wasn't oil at all, but brake fluid leaking somehow from the reservoir in the engine compartment. The level of fluid is to the cap, when i checked before the trip it was exactly on the fill line. Of course a light bulb went on and i checked the passanger side calibers. And sure enough one of the two calibers appears to be seized and is not moving at all.

Now for my questions:

What would cause only one of two calibers to seize?

Would a single seized caliper cause the fluid level to raise enough to fill and overflow the reservoir? If not what would?

What should i do to fix/troubleshoot both issues?

 

[CougarSE]

Heat kills calipers. I imagine slide pins on the right side caliper are seized as well causing excessive pressure on the inside pad. If the vehicle is driven like this for some time it will heat up and warp the pistons inside the caliper. When warped they stick in the bores and your vehicle pulls, to the left in your case as there is no brake pressure on the right side to balance. Warped rotors can be a result of caliper problems, check the run out on the rotors before you install new parts. Or just replace the rotors.

Now the brake fluid. If the pistons are pushed back inside the caliper for some reason this will cause the brake fluid level to raise. This issue I'd have to see to further diagnose.

So what to do.

Pull the caliper off the right side of the vehicle and inspect the caliper slide pins. Do they move easily? If not beat them out and replace. Worst case scenario you will replace the caliper bracket.

Check the caliper next. Do the pistons move in and out of the bores easily? Press them in with a C clamp on one of the brake pads first. They should move in easily. If they are hard to push in replace the caliper.

I would go to the auto parts store and buy a "loaded pair" of calipers. Much cheaper than buying all the parts alone.