Grinding noise, but good brake pads

Well the brakes feel good, no complaints. However, I found a problem.

The Riv was driven straight from the shop to my garage and sat overnight. Drove to work this morning, then home for lunch, only to find a small puddle of oil in the garage where I always park it, just inside of the left front tire location. Look under the car and can't see much, so I pop the hood and find the brake fluid res has fluid all over the outside, it has run down over the booster housing, and onto the trans then to the floor. The lid is on tight, and the reservior is FULL to the max. Overfilled and spilled, or the system now has too much fluid due to the full pads now on the car. But it doesn't seem likely to me that it would blow past the lid that is on tight? Is there another seal, maybe at the bottom of the res that could leak?

Anyway, I called the service mgr today and they are going to clean up the engine bay over lunch tomorrow. Big question for me is would overfilling, then driving/braking cause the fluid to blow out a seal? In which case, there may be a repair needed?

I think if the reservoir were overfilled, the pressure could easily squeeze fluid through the seal of the master cyl.

Could it be the fluid was there from when they spilled it during install and weren't aware? All you need to do is clamp the caliper open, and the fuid will shoot out of the MC.Maybe it wasn't actually leaking while you were driving, just dripping from a sloppy install.

in theory the brake fluid resivoir has enough fluid to go from being full with new pads and rotors all around to pads and rotors really low, you should still have enough fluid for that without adding any. Then when you compress the caliper pistons, you refill the resivoir from the pistons! If you add fluid somewhere along the line, you'll have enough in there to overflow it when you go back to new pads.

It can also be a nice way to gauge pad life - resivoir full = new pads and rotors - resevoir almost empty - check those pads!

I know the reservior was just slightly above the minimum fill mark on the tank last week, so it seems most likely they overfilled it during the job, since it is currently filled far above the max line. Who knows, they may have overfilled AND spilled in the process. All I know is the fresh fluid starts right up at the cap. I'll have to keep an eye on it for more leak issues after they clean it tomorrow. They offered me a loaner to get back to work if I want, or it may take up to an hour to get done. I should see if they'll give me a Super or Enclave.

BTW, the inside pads were almost completely gone on both fronts, while the outside had a solid 1/4" left. Why would they wear so unevenly? Poor install, back whenever... ?

I find people tend not to clean or lube the caliper guide pins well enough. I make the pins (and inside the caliper brackets) really clean and I use never-seize instead of the caliper grease many calipers come with.

Would account for uneven wear.

I removed 3 turkey basters worth of excess fluid from the reservior this morning, just to get it down to the max fill mark. Then took it in at noon and they cleaned up their mess in and under the engine bay. Looks good now, but frustrating to have to do this. Same dealership owner when I had my F150 and had them do a winter oil change, drove home and parked in the driveway only to find a big puddle of oil in the morning. Not a leak, they simply didn't bother to catch the spillage when they removed the filter, just let it run all over the place.

Hey Dave

I "second" what Derek said. I've gone so far as to put the OE stainless/plated caliper pins in a drill chuck, spin them fast while polishing with ScotchBrite and a dab of antiseize (to keep from lelaving dust), then l clean them with denatured alcohol (ummm... the cheapest dry gas) then when reinstalling them, lube them with anti-seize (the silicone lube turns to boogers after a certain time). The aftermarket zinc chromated pins are probably not worth polishing, that would strip off the coating - just replace them.

Albertj