Rear disc brake issue- need advise

[BentleyArnage]

Oops! What you're getting is ABS application. When you compressed the caliper, you allowed old nasty brake fluid to get back to the ABS manifold. Now those little valves and such are stuck, causing the thumping noise. In the future, open the bleeder when compressing the caliper piston. You can also clamp off the brake line as well. You never want that old crap getting back into those valve assemblies.

 

[OR VietVet]

Plus, 30k is the right time to flush the system out. Others say 50k but I prefer as clean as possible brake fluid.

 

[Tbruz]

The caliper pistons pushed back very easy with the reservoir cap off/loosened.
The machine shop blasts the inside hat of the rotor to ensure no corrosion is present. I hit the trucks hubs mating surface with a rust colored scotch brite pad on my drill to remove anything there. i had sprayed fluid film on the hub but wiped all that off clean as my first WTF is wrong here analysis response.
I am leaning toward rotor warp as well and I may just bite the bullet and install new rotors , I just want to know whats- what now.
Thanks
T

 

[Tbruz]

Bently Arnage; if its ABS activation why isn't present when its cold....Only after they've up?

 

[swathdiver]

After about 15 minutes of use I can hear a rhythmic "thumping" at each application of the brakes. Its obviously rotational, heat related and coming from the rear brakes- NO shimmies or pulsating as you'd feel from warped rotors. I've taken everything apart again to see if anything obvious is wrong - all looks good.

Seems to me like a piston is hanging up slightly when it gets hot. Time for a rebuild, especially if original. Been there, done that, got the burned up rotor and pads in lieu of the t-shirt.

 

[TollKeeper]

I am leaning towards warped rotors. Like someone mentioned before, you can turn these rotors, but any more, it's not really recommended. I have not turned a rotor in nearly 24 years

 

[OR VietVet]

Like @swathdiver said, the rotor could be getting warped because of the caliper sticking when heated up. That is why I was talking about all the possibilities I listed and added the brake fluid flush, especially after 30k miles and since many years back, I have not machined rotors, I replace them. All manufacturers need to meet an AVERAGE of mpg and saving weight of thick rotors is a casualty of that.

When I bought my 05, the very first thing I did was flush/change ALL fluids, period. I wanted a baseline of how fresh they are instead of just hoping. Then I followed the "better to be safe than sorry" saying and will be changing those fluids on my own severe schedule. Hell, I even cleaned and lubed every single piece of rubber seal on this thing. But, I am an **** person when it comes to maintenance. My signature says so.

 

[swathdiver]

The caliper pistons pushed back very easy with the reservoir cap off/loosened.

Cold...

 

[OR VietVet]

Cold...

EXACTLY!!!!!!!

 

[corvette744]

Have you tried when your hearing the noise to simply push the parking brake pedal down?Would answer the parking brake pads sticking-ask me how i know.I removed mine and thru them in the trash.