locking front caliper

anybody else experience a locking front caliper? i have 2006 m3 with the front left caliper locking up as i drive. i bled the system and replaced the line to the caliper. only thing left is to replace the darn thing. before i dish out $400 i wanted to make sure im not missing something to avoid that.
with this being said in case i do have to replace it, anyone know where i can find a used caliper?

Look at Turner MS,Ebay and Google the part #. You can find rebuilt ones for about $120 core included and new ones for $340. My friend bought a No Name rebuilt one for under $120 and it was rebuilt from an OE casting...
If you are handy, you can also rebuild it yourself with a $20 Rebuild kit....just Youtube caliper repair
Used calipers may be cheaper.
I bet a dust boot tore openon the caliper or got unseated and you now have corrosin on the piston. Check it carefully with a FLASHLIGHT. This is very common for BMW's....the calpers need maintenance too.

What he said^^
I would just purchase a rebuilt unit. NAPA in Glen Cove (long island) has them for about $105, ask for Jimmy, and mention Michael with the BMW sent you, maybe hell take a few more $ off.

Fact of the matter is any re-built unit is going to be an OEM calaper casting anyway, and most of the internals are made by centric, or Ate, so a rebuilt is not much different than going to a BMW stealer and buying a new one. I would not buy a used one, unless you are planing on re-building it, just spend an extra $30-$50 and get somthing re-built with all new parts.
Can also check your local pepboys, autozone, ect.

FWIW- this is a good time to flush out the system too.

Originally Posted by mzeed

Look at Turner MS,Ebay and Google the part #. You can find rebuilt ones for about $120 core included and new ones for $340. My friend bought a No Name rebuilt one for under $120 and it was rebuilt from an OE casting...
If you are handy, you can also rebuild it yourself with a $20 Rebuild kit....just Youtube caliper repair
Used calipers may be cheaper.
I bet a dust boot tore openon the caliper or got unseated and you now have corrosin on the piston. Check it carefully with a FLASHLIGHT. This is very common for BMW's....the calpers need maintenance too.

Hands down that rebuild kit from Turner was perfect for the job. Took me about an hour (took my time) and a tube of brake caliper assembly grease to work with. The piston had a little corrosion that I buffed out carefully with some steel wool and had to pick at some rough spots to get it smooth. I used the wool in the chamber too. The "toughest" part is how to get the piston all the way out. I had someone pump the brakes for me SLOWLY until it popped out and I clamped the brake lines closed. Using a compressor seemed a little dangerous. I followed this video as some people have trouble sliding the gasket and piston back in. Do it exactly with plenty of grease (with gasket hanging off the edge of the piston) and it works perfectly. I ended up doing both fronts

Great video. Thanks.

Don't know if you're still in need. If so, I have an entire set of brakes, including calipers, rotors, and pads from an '06 M3 for sale. I took 'em off when I installed Competition brakes.

I don't need much for the set. Shipping prob wouldn't be too cheap though. PM me if you're interested