Diagnosing Creaky Brake

alvocado · September 27, 2020

My driver's side rear brake on my '11 Yukon is making a creaky noise when activated and I'm out of ideas on the cause. I cleaned and lubricated both guide pins but it didn't help. Both pins slide as expected and don't make noise when moved manually. I pulled the caliper again today and inspected and cleaned the piston. The piston seals look fine with no leaking, bulges, etc. The piston surface cleaned up with brake cleaner and depressed easily prior to removal with a c-clamp. There aren't many moving parts so I'm out of ideas other than the entire caliper may be bad.

Here's a video with the tire off, truck on stands and my son depressing the pedal fully to the floor. It sounds like an old bed spring.

Any ideas are appreciated.

slowTA · September 29, 2020

The fronts on my '88 Firebird (with C4 HD swap) with Hawk pads started doing that ages ago and I never figured it out, figured some part of my assembly was off. Then my 2016 Sliverado started doing it occasionally and I never touched them! After doing the brakes on my truck it went away, so pads and rotors along with a little fresh disk brake lube were the only changes.

My current theory is the pads... but only because I greased the snot out of the Firebird brakes with no luck and I really doubt it could be the rotors!

Speaking of GM rotors, check out this wear pattern!

Milspec23 · October 7, 2020

I know recently doing mine own breaks the slide pins need to be in the correct order as far as Grooved on top smooth bottom or visa versa depending on your own vehicle and mine were out of wack and caused squeling and abnormal where but not until 20 30,000 miles did I start to notice.. hope this helps figured it was worth a reply

swathdiver · October 7, 2020

On 9/27/2020 at 6:36 PM, alvocado said:

My driver's side rear brake on my '11 Yukon is making a creaky noise when activated and I'm out of ideas on the cause. I cleaned and lubricated both guide pins but it didn't help. Both pins slide as expected and don't make noise when moved manually. I pulled the caliper again today and inspected and cleaned the piston. The piston seals look fine with no leaking, bulges, etc. The piston surface cleaned up with brake cleaner and depressed easily prior to removal with a c-clamp. There aren't many moving parts so I'm out of ideas other than the entire caliper may be bad.

Here's a video with the tire off, truck on stands and my son depressing the pedal fully to the floor. It sounds like an old bed spring.

Any ideas are appreciated.

ABS Pump and or air in the line? Did you grease the brake pads/shims? But even that would not cause the issue in that video I think.

Last March we did the front brakes, the rears were done in 2017. This March I had a piston on one of the front calipers fail to retract a little which caused a vibration. Took the wheel off, pushed the piston back in, cleaned and greased everything and all was well for a few months until one very hot day that same piston would not release and nearly set the truck on fire. So my daughters and I replaced everything and then took a look at the rears, one piston was not retracting all the way and not wanting a repeat of the front, went ahead and rebuilt them ourselves and then used 6 quarts of brake fluid to flush and bleed the entire system manually and with our Tech-2. Back to stopping on a dime.

GM offers no part numbers to rebuild the rear aluminum calipers, however, the pistons and seals for the front work perfect. Use GM OE only as they are perfectly sized for the OE piston bore. Aluminum calipers take the fine thread bleeder. I have all part numbers if you need them and they are posted over at the TahoeYukon forum too.

Edited October 7, 2020 by swathdiver
Additional Information

Milspec23 · October 7, 2020

I'm just doing this on the fly so I'm not sure if you read what I wrote about a similar issue with the slide pins look for your specific vehicle and make sure the smooth and the one with a groove are in the correct order IE groove top smooth bottom or vice versa and on top of that before buying a new caliper I would and again I'm not sure if you already have the red or did this make sure you lube up all the parts the piston the back of the back of the clipsall places that are going to get friction minus this goes without saying the pad surface that contacts the rotor I know I know but I just got to say it

slowTA · October 7, 2020

5 hours ago, Milspec23 said:

I'm just doing this on the fly so I'm not sure if you read what I wrote about a similar issue with the slide pins look for your specific vehicle and make sure the smooth and the one with a groove are in the correct order IE groove top smooth bottom or vice versa and on top of that before buying a new caliper I would and again I'm not sure if you already have the red or did this make sure you lube up all the parts the piston the back of the back of the clipsall places that are going to get friction minus this goes without saying the pad surface that contacts the rotor I know I know but I just got to say it

I'm sorry, but I'm not following this at all. Are you saying that the slide pins aren't round in every case? By grooved or smooth I can only think that you're talking about the ends of the pins, the threaded end should have grooves to hold the dust boot and the other would be smooth, but they only go in one way.

alvocado · October 8, 2020

The slide pins looked identical to me and made no noise when manually moving the caliper with the piston compressed to allow some movement while mounted. I've removed, cleaned and lubricated the pins twice with no change.

The sound appears to be coming from the caliper body when I listen with my ear next to the system. In my experience, failure to clean and lubricate the pad mounting surface on the caliper bracket would only cause squeal due to pad vibration.

The brakes were bled last summer but I may bleed this corner to make sure fluid is flowing through the caliper properly. There are no unusual marks on the rotor or pulling due to uneven braking.

slowTA · October 9, 2020

Just for another data point this is my Firebird, I'm waiting for the pads to wear down to support my theory.

alvocado · October 13, 2020

I removed the pads, cleaned the caliper bracket and shims, lubed the shim surface and pad ears and reinstalled. No change.

slowTA · October 13, 2020

But did you put in new pads or the old ones? I bet the sound will stop with new pads... it doesn't make sense, but it seems like that's what did it for me.