After front brake pad & rotor replacement, front calipers are stuck

[crimecanine]

I replaced my 2002 Envoy's front pads and rotors according to instructions such as

How to Change Brake Pads and Rotors

Summary: How to Change Brake Pads and Rotors Difficulty: Moderate Estimated Time: 4 hours Part Numbers: Varies Cost: Varies NOTE: All pictures are of the right rear brake assembly. All instructions apply to my 2005 Trailblazer I6 4x4; they may be different on other years or models. Many...

gmtnation.com

Note: Compressing the caliper pistons was much more difficult than it looks in videos. I used a clamp and had to really crank on it. (I did NOT pinch off the brake lines.)

I bled about a pint of fluid through the bleeder on each front caliper. I pumped the brakes until firm and topped off the master cylinder. I didn't touch the master cylinder other than sucking out old fluid and adding new fluid.

Upon test drive in my driveway, the front brakes are extremely tight: the vehicle will not move while in gear at idle. To move it, I have to push the accelerator a fair amount, and I can hear binding/sticking at the front wheels.

I jacked the rear, and the rear wheels spin normally by hand. I jacked the front, and I cannot rotate the wheels by hand.

To fix it, so far I have removed the front right wheel and caliper bolts. The glide pins are fine. I opened the bleeder and sucked several ounces of fluid into a vacuum pump, and the caliper is still tight. Therefore I doubt that the problem is residual pressure (e.g. long booster push rod or clogged hoses). I cannot pull the caliper off of the rotor.

1. What may have caused the difficulty compressing the pistons and the tight brakes? I have a guess but would like your unbiased ideas.
2. How can I remove the calipers and find and fix the problem?
3. Bonus question: When compressing the pistons, bleeding brakes, etc., is it important to have the ignition on, i.e. to have the ABS module powered? (My OBD scanner isn't smart enough to talk to the ABS.) I wondered whether that's a factor.

I have a guess about the problem, based on this thread

04 trailblazer, brakes dragging after new pads, calipers, master cylinder

So, I took my TB to a guy who does my auto work to get the brakes improved. I had like they were a little weak and I tow my camper with it, so wanted it right for spring. he pulled all pads off, and odd thing, he told me both front calipers froze and even with clamps he couldn’t push them out...

gmtnation.com

but I don't know how to do my next step: remove the stuck calipers. I'm searching youtube.

 

[Mooseman]

1. What may have caused the difficulty compressing the pistons and the tight brakes? I have a guess but would like your unbiased ideas.

Likely the calipers are just worn. I've had a few do that however never both at the same time.

2. How can I remove the calipers and find and fix the problem?

You'll either have to pry them up using the rotor as the pry point or use a large c-clamp to compress the pistons a little.

3. Bonus question: When compressing the pistons, bleeding brakes, etc., is it important to have the ignition on, i.e. to have the ABS module powered? (My OBD scanner isn't smart enough to talk to the ABS.) I wondered whether that's a factor.

Not at all and have never heard of that. There is an argument going around about opening the bleeder before compressing the pistons however it is not indicated in any manual to do this. It's supposed to prevent pushing dirty fluid into the ABS module. It doesn't hurt to do it but not necessary.

So new calipers are in your future. And when bleeding, it wouldn't be a bad idea to flush all the old fluid out at all four.

 

[crimecanine]

Likely the calipers are just worn. I've had a few do that however never both at the same time.

Ok. I plan to buy new calipers.

My guess was from this prior post:
"The phenolic resin pistons can swell with age at the outer end. When the pistons are pushed back in for new pads they can stick."

04 trailblazer, brakes dragging after new pads, calipers, master cylinder

So, I took my TB to a guy who does my auto work to get the brakes improved. I had like they were a little weak and I tow my camper with it, so wanted it right for spring. he pulled all pads off, and odd thing, he told me both front calipers froze and even with clamps he couldn’t push them out...

gmtnation.com

although my pistons seem more like metal than resin when I tap them with a metal tool.

You'll either have to pry them up using the rotor as the pry point or use a large c-clamp to compress the pistons a little.

Perfect -- a crowbar eventually worked, against the rotor.

So new calipers are in your future. And when bleeding, it wouldn't be a bad idea to flush all the old fluid out at all four.

Ok, I'll follow EricTheCarGuy's caliper replacement video

and then tackle the rear brakes, including parking brakes.

Would Autozone calipers be alright?

They offer a $72 version with mounting bracket:
Duralast Brake Caliper 18-B4799A, SKU # 564453 (passenger side)

https://www.autozone.com/brakes-and-traction-control/brake-caliper-front/p/duralast-brake-caliper-18-b4799a/564453_0_0

and a $62 version without mounting bracket;
Duralast Brake Caliper C639, SKU # 692412 (passenger side)

https://www.autozone.com/brakes-and-traction-control/brake-caliper-front/p/duralast-brake-caliper-c639/692412_0_0

Despite the very different part numbers, the mounting bracket is the only difference I see. My bracket appears fine to re-use, but I can pay the $10 extra for the first caliper is it's beneficial.

 

[northcreek]

On something this old I would replace the rubber lines along with the calipers, I had one collapse internally and you can't tell visually when they go bad. I have had good luck with AZ brake parts when I don't have the time to order preferred brands.

 

[crimecanine]

On something this old I would replace the rubber lines along with the calipers, I had one collapse internally and you can't tell visually when they go bad. I have had good luck with AZ brake parts when I don't have the time to order preferred brands.

Ok, I see ACDelco calipers and hoses reasonably available from Rockauto.

For calipers, what are the thoughts on new versus reman?

New ACDelco: $91

More Information for ACDELCO 18FR1891N

Reman ACDelco: $50 + core $45

More Information for ACDELCO 18FR1891

 

[crimecanine]

I see this old thread on new vs reman calipers and am still pondering:

New vs reman brake calipers

As most of you know, I am pretty anal about handling and brakes. When switching to my winter rims on our 04 Trailblazer LT, I noticed the pads were getting down a bit so I popped off the caliper and looked at the pads. The NAPA Adaptive One pads still had lots of wear left (about 20,000 km since...

gmtnation.com

"New calipers made in China vs remans made by the factory."
"Remans don't change out the piston because it is usually a resin piston"
@Chickenhawk , what did you choose, and how did it go?

 

[northcreek]

For calipers I now go to AZ because if I get a bad one it's just a trip back to the store, even after a period of time.
I don't have the faith that I once had in AC Delco, I've had some good/bad luck with some of their stuff and they sometimes slap their name on other manufacturer's parts which shouldn't be.

 

[Mooseman]

Eric's video is pretty good (except for the extra blah, blah, blah) with just a couple of notes.

Put some silicone grease on the bracket where the shims go to prevent the cast iron under them from rusting and jacking the shims thus seizing the pads. And I don't know what his deal is with the copper washers since pretty much all OEMs use them. Just be sure to use new ones that usually come with the caliper. Also, I use blue Loctite on the bracket to knuckle bolts where he says to use some oil. I have had those bolts come out on me once so ever since then, I Loctite them. And if the new banjo bolt is a different sized hex head, just get the wrench for it. Why have an old bolt on a new caliper?

One last thing, I would go with a caliper with the new/rebuilt bracket so you will have new slides, bolts and boots. Why cheap out now?

 

[crimecanine]

Eric's video is pretty good (except for the extra blah, blah, blah) with just a couple of notes.

Thank you. I agree with all that. Copper is softer, thus a better seal than steel. I had wondered the necessity of Loctite. Thanks for your report.
FWIW, I ordered new ACDelco from RA today.