NEED HELP Brake squeak driving me F*&^%$# insane!

[littleblazer]

I literally quit. Like I have thrown every god damn trick I can at this thing short of lighter fluid and a match. So here it is.

2003 Escalade, 270k miles or something like that and we just finally replaced one of the stock calipers. It was nice, came from GM with a new bracket, hardware and caliper. Thing goes on, we bleed it and its great... except coming to a stop it chirps like a school bus.

So I pull it back apart and find the lower caliper slide is stuck in the bracket. Cool. I lubed it up bored the hole to fix the casting flash and it worked mint for about 20 miles. Now it has a cyclic whirling noise equivalent to a squeaky door that never stops squeaking. So I swap the old bracket on. Works okay for about 20 miles again and then is non stop after that.

At this point I'm pulling out my hair. Dust shields are gone, e-brake removed (Cable snapped years ago), and there is so much grease back there I don't think the brake is actually doing anything... So I am at a roadblock, is the new caliper sticking? Is there still air in the line or could it be an abs issue? (this has the 4 sensor 4 line system on it because of the AWD so...) Does anyone have any other suggestions before I torch the thing. Also, how freely are the slides supposed to move. Are they free floating or are they supposed to have some resistance. I cleaned them off and lubed them with a mixture of caliper grease and ATF only because the caliper grease by itself is like silly putty.

Any help is much appreciated.

-Paul

 

[mrrsm]

FWIW... from 21:49 onward in this YT Video from South Main Auto... Eric "O" describes the WHY of his unusual placement of Silicone Brake Grease when assembling the Brake Calipers on a Full Size GM Truck and he gets under the skin of WHY he applies the stuff and WHERE in contrast to the way many of us might be using this goo.

Like you... most of us with years of Mechanical Repairs are 'Worth our Weight in Wrenches' and have performed more than our fair share of Brake Jobs. And yet.. there may STILL be something New to Learn. I learned a lot from watching him work on this very problem. Hope his Instructions prove Helpful:

Here is the South Main Auto Channel for other Great GM-GMC R&R Videos:

South Main Auto Repair LLC

Hey there viewers! My name is Eric O. and I own and operate a small town 3 bay shop in upstate NY. I grew up in the automotive industry (in my parents shop) ...

www.youtube.com

 

[Maverick6587]

Is the piston wore on the sides, does sit firmly in the shaft? It could be loose and making noise on the backside of the brakes? The one that gets me frequently is putting too much grease on the slide pins and they end up getting "hyrdrolocked". What type of metal is the hardware made of. I've had a few times where they were cheap and painted which caused some sticking issues even when they were greased well.

After watching a few of Eric O's videos, I stopped putting grease on the calipers where the pads slide. I noticed how fast the grease just grabs a ton of debris, in as little as a week. I still put grease on the back of the pads and the pins though.