The Brakes on my 185 have always groaned loudly when turning and even when coming to a complete stop, but not when moving fast in a straight line.

I finally had enough of it today and replaced the linings (which weren’t worn out). Cleaned the rotors and they looked brand new.

I even replaced the calipers because the old ones looked nasty and were seeping.

It’s like i did nothing at all and they do the exact same thing.

These are the exact same brakes older Cirrus’s use and I’ve probably flown 500 of those and never heard this noise before.

My 185 is on 8.50 tires.

Anyone have and experience with this?

Wheel bearings?

Can’t be that either because it did it with my old wheels also.

It’s both sides. And only when you’re on the brakes.

Perhaps a stupid question but did you follow the brake in procedure provided by the manufacturer of the brake linings?

Yes, did 3 aggressive stops. Sounded the same before and after.

I once had brakes that made similar noises. Talked to a mechanic, who said he thought the wheel nuts were too tight.....I raised my eyebrows. He unassed the wheel nuts, backed them off one castellation, and re-safetied. No more noise when braking.

I have NO idea how or why that worked.

MTV

The caliper piston seal has a square cross section and provides a residual amount of pressure allowing the disc pads to lightly rub even when not applied. My Maule does that and is loud enough to convince you that your fighting applied brakes when managing the plane on the ground by hand. Does it while taxiing, too. When I lift the wheel off the ground, it spins easily while making the groaning sound. If I rattle the caliper on it's sliding mount, it'll stop because the rattle increased the space between the pads and rotor. But next time you apply the brakes the noise resumes. Cleveland single puck brakes. Not helpful info but it's a gremlin others have chased.

I use my brakes a lot harder than most pilots I know which may be a factor.

MTV: A theory on your mechanics approach is that the looseness provided by the wheel bearing at a looser setting would allow the rotor to expand the caliper? Could work. I may try that, too...

This is much louder than the typical brake drag. Like way way, embarrassingly loud. Almost like a horn

mtv wrote:I once had brakes that made similar noises. Talked to a mechanic, who said he thought the wheel nuts were too tight.....I raised my eyebrows. He unassed the wheel nuts, backed them off one castellation, and re-safetied. No more noise when braking.

I have NO idea how or why that worked.

MTV

Weird. I’ll check that

What MTV said is weird but I understand it. I had a similar problem as you are having and I couldn't figure mine out either until I started checking everything from the fuselage to the tire. I double checked all the bolts and one of the bolts that goes on the bracket over the gear leg attachment on the fuselage was just slightly looser than the others. Maybe an 1/8-1/4 turn on the bolt/nut.....noise disappeared. Not saying it's the same problem, but it worked for me..

Been back and forth from floats to wheels a few times, and the problem persists.

Different Wheels on it, and now different caliper/linings.

I wonder if the rotors are defective or glazed or something this whole time. Only reason I didn’t change them is they look and feel perfect.

My old Citabria 7ECA had a similar-sounding "groan" during braking. Loud enough to be a bit embarrassing at times... Had the mechanic check the linings, calipers, rotors, and everything else we could think of, all to no avail. Then one day it just quit making the noise. I'm clueless as to what might have been causing it, and why it suddenly stopped.

Do the caliper pins slide on the torque plates without restriction?

Yes, the new calipers included new pins, which were greased.

Wacky rotors would be my guess, as you posited above.

Maybe a litle dab of antisqueal between the piston and floating pressure plate?

I have the same issue on a complete new set of ABI wheels, brakes and calipers. Broke in properly and only the right side is noisy. Drag the brakes and get them hot and it disappears but comes back after they cool. Might try to back the nut off and report back.

Ill try the same.