quick question: I did check torques on caliper bolts, but maybe I have wrong measurements. isn't it 67 (or 63)? thanks.

 

FWIW my Volvo S60 does this all the time. I have replaced the pads and rotors at regular intervals no problems found, seems there is just enough play to let the assembly/pads move F and B to make the clunking sound.

 

Forgot about the Ebrake. Since it is a basic drum brake assembly if you have the brake on overnite and there is rust, corrosion etc. in there a brake shoe could stick to the inside of the rotor and when you move the car it 'pops' free. My Volvo wagon does this occansionally. A way to clean off the inside of your drums in the rotors is to hold the brake on with moderate pressure and back up the car at the same time. This has the effect of scraping some of the corrosion off the inside of the drum.

 

well folks, let's chalk it up to worn out caliper springs. the last thing i did before i changed them out was to remove them and drive around the block. the clunk was much more prevalent. so i just installed new ones (thanks suncoast!) and issue is gone. hope this helps somebody someday!

 

I have the same problem with my 87 944s, Thanks for posting the solution

 

Simple.
You reverse out of your drive way. Brake pads move to one end ever so slightly.
You start driving and the first time you brake they move the other way and hit the caliper.

 

By caliper springs are you talking about the flat metal curved pieces held in by the locking pin across the center of the calipers pushing "Down" on the pad plates? That is such a good find to catch that. I'm glad you finally found the answer.

 

Geez you just solved the problem I had 20 years ago on my 914. Exact same symptom. Drove me crazy. Never fixed it and the car is long gone. But now I can stop losing sleep. Thanks!

 

The springs do not prevent sideways movement. You will still get this sound when the brake pads wear down and the overall play is larger. It is "normal".
New pads also help prevent this, for a while.

 

I hear the same sound.

At last pad change I put in titanium backing plates (no adhesive) between pads and pistons instead of the adhesive-backed damping plates.

Presumably the pads are slipping forward and backward slightly in the caliper.