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I have a 2008 GH2 Impreza, foreign used, a year old... I'll give you all the whole history...
Started getting vibrations when I mash brakes, I didn't have time/lazy to check it out. By the time I did the rotors were warped.. thus the vibrations... but I left it so long the front bushing, big one, was damaged. I changed the bushings, put new rotors, new pads..original.. I started getting a woo woo woo noise while driving. Did some research, could be the wheel bearings, so I changed both. Then I started getting a... grinding noise (grrrrr) is the best I can describe it from the front left, but only as the car slowed to a stop. Took it to someone ... the front left pads were disintegrating!!! The middle where the pad is split was crumbling and when you looked at the pad's outer edge, along the entire length, was cracking.. yes cracking. And I had the pads on for only a couple months. I drove a B2500, and 2 Grand vitaras before.. roughed up all 3 vehicles...on road and off and never saw this before. So I changed pads again this time I put the mintex. Same noise. I just replaced all the rubbers on the calipers, piston and sliding pin rubbers. Same noise....

Can anyone help please!?!?!?!?

Try using OEM Subaru disc pads or Hawk. Mintex made alot of noise and dust on my car. Swapped to OEM Subaru and worked great to this day.

Mintex makes the squealing noise. I probably will try the OEM just to see, but I got the grating, grinding noise with OEM pads... and when I took them out the pads were breaking up!! Now still getting the same noise... I am thinking it can't be the pads... but i'll try..

I agree, Its hardly likely that the pads are the issue.

Have you checked to see if the calipers themselves are functioning properly?

Yip, yesterday I took down and serviced both calipers, replaced all the rubbers.

I feel that the piston may be sticking and that the excessive heat from the pad touching the rotors all the time causing the pad to crack and brake up...

I have a pair of GH2 calipers if you wanna try / buy...

I was also thinking that a sticking piston might be at fault.

same here....also what grease you used on it??

When I changed the rubbers on the piston I did not use any grease, I have serviced calipers before on other vehicles and never used grease there, just brake fluid to lube up and ease the install. On the sliding pins I used the grease that came with the repair kit, and it was an original Subaru repair kit..

@air wick, that is what I was thinking, that is why I serviced the calipers... The piston was in good condition, and well all the rubbers changed.. but I guess anything is possible. I don't want to buy calipers just yet, but just in case, how much you want for them??

I should throw in I am getting a woo woo woo noise from that side as well, but the bearings are new...

And yes I know I could go to a mech, but I dont trust them much, plus I like to figure stuff out and know what is what with my vehicle.. Wen I reach the ultimate dead end i'll go to one...

take a lil read...

http://forums.nasioc.com/forums/showthr ... ?t=2131626

they will get lubed up with the synthetic brake caliper grease and reassembled,

That comment is a bit vague, and there is a comment further down by someone saying not to use grease to lube the pistons. Someone on another forum claims it is in the service manual to use brake fluid only on the piston seals. I could be wrong all together, or maybe Subaru is different.. I'll do some digging on that tomorrow.. Some say there is special grease that could be used there, I don't know if it is different to the sliding pin grease.. I don't know if the grease provided could be used on the piston as well.. I'll do some digging cause I always thought you used brake fluid there...

Hey i did a similar service to my sticking rear calliper. We used the red grease that came with the kit on the sliding pins and on the piston and so far car works great. My one sticking calliper caused all sorts vibrations and noises when the brakes heated up sounding almost as if i was driving with a flat.

Also take the opportunity to do a brake fluid flush as the moisture gathered by the old fluid accelerates corrosion within caliper.

Could be the off chance that the caliper housing is warped. Tried everything here and more before we found out the problem on my tiida. It was warped by only a small degree, but enough to cause the pistons to stick when cool, ONLY WHEN HOT, so when off the car, or during a quick test drive after servicing, everything worked like normal.