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Discussion Starter · #1 ·
I have a 2002 in another state that sits mostly and used a day a every other month.

The left front brake is hot - appears stuck.

Im thinking of taking the wheel off to look at it and try to free it.

To take the caliper off what tools would I need? Socket/wrench sizes would be helpful.

Thanks.
 

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2004 chevy trailblazer_lt
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If I correctly recall, the wheel lug nuts need either a 21 or 22 mm socket. The caliper mounts to the caliper bracket using bolts that need a 15 mm socket, and the caliper bracket requires an 18 mm socket.

I seriously doubt that you will need to remove the caliper bracket, but if you do, you will need one heck of a breaker bar along with a 4 - 6 foot pipe for leverage.

Good Luck!
 

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2003 TB LTZ
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If I correctly recall, the wheel lug nuts need either a 21 or 22 mm socket. The caliper mounts to the caliper bracket using bolts that need a 15 mm socket, and the caliper bracket requires an 18 mm socket.

I seriously doubt that you will need to remove the caliper bracket, but if you do, you will need one heck of a breaker bar along with a 4 - 6 foot pipe for leverage.

Good Luck!
I don't remember the caliper bracket bolts being particularly hard to get off - but you can make a "breaker bar" setup with two wrenches out of your set by putting the closed end of the correct size on the bolt, and using the closed end of another wrench locked into the open end of the one on the bolt. I have a 2 ft breaker bar so I rarely have to resort to this, but it does sometimes come in handy when you can't get a socket on the bolt in question. I can't remember if I had to do that on the TB when I removed the brackets
 

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You also need a jack stand. Don't try to work on it supported only by a jack. (And don't use any substitutes, like a concrete block).

I have an '02 envoy. I use a 3/4" on the lugs - the fit is tighter than a 19mm. But you can just use the lug that goes w the spare tire for that.

I'm pretty sure my caliper bolts are 17". Or maybe it's that the bolt is 15 but you need a 17 to hold a nut on the slide sleeves? I forget. But it can be a 2-wrench gig because there is a nut you will probably have to hold to get the bolt loose. Just grab a full set of mm wrenches (10-19 or whatever). They're not that expensive.

And, for what it's worth, one very likely thing is that your inner pad is hung up in the bracket from rust build up on the bracket. Have something on hand for picking at/filing at rust. But I'd not count out having to get the bracket off. And they are larger bolts that go in at - I think - 100 ftlb. I also wouldn't be surprised if some manner of thread locker went onto them. Add in some age and rust and it can take some doing.

So try the double wrench technique. But if needed, go to the "poor man's impact tool" technique. Make sure the truck is on jack stand/s. Wear gloves. Get the wrench onto the bolt, and make sure it's on there straight and good an snug. Hold it on & steady with a couple of fingers at the bolt head if you can. Take some manner of BFH - I use a 5lb mini sledge - and hit the darned wrench as squarely and as hard as you can. Straighten up and check the wrench. Hit it again! And repeat. And this is no time to be shy. If you think you hit it hard...hit it harder...

(And make sure you know which way is loose/tight! "Righty-tighty / lefty-loosy" - but you'll be looking at it backwards!)
 

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Discussion Starter · #7 ·
Here’s what I found.
Wheel Tire Automotive tire Motor vehicle Tread

Hood Automotive design Automotive tire Motor vehicle Automotive lighting

Hood Automotive tire Windscreen wiper Motor vehicle Automotive exterior

Hood Wood Bumper Automotive exterior Tints and shades

The top of the inside brake pad seems to have been worn away more than the bottom.

I don’t know how that got started, but both pistons on the caliper move freely.

I lubed The pads and reinstalled them. The hot problem persisted.



Next I replaced the pads with new ones and test drove. The new pads seem to have fixed it, but I wasn’t out for a long drive.

I guess once the old pad started to wear unevenly it put a bind on the sliders and wouldn’t release.

The only tools I needed were the onboard tire tools and jack plus a 17mm and an adjustable wrench.

Thanks again for your help.

If the problem comes back I will replace the caliper.
 

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Here’s what I found. View attachment 60207
View attachment 60205
View attachment 60206
View attachment 60204
The top of the inside brake pad seems to have been worn away more than the bottom.

I don’t know how that got started, but both pistons on the caliper move freely.

I lubed The pads and reinstalled them. The hot problem persisted.



Next I replaced the pads with new ones and test drove. The new pads seem to have fixed it, but I wasn’t out for a long drive.

I guess once the old pad started to wear unevenly it put a bind on the sliders and wouldn’t release.

The only tools I needed were the onboard tire tools and jack plus a 17mm and an adjustable wrench.

Thanks again for your help.

If the problem comes back I will replace the caliper.
I wouldn't replace the caliper first. You pull off the bracket and clean the sh***zzle out of it to get the rust off. The focal point is the notch where the pad ears slide.

Then apply good quality brake grease to the bracket notch to hold off the rust - very thin coat. Then make sure you have new shim clips but the grease goes underneath on the bracket as rust prevention. Putting it on top attracts crap and contributes to the binding.

Your focus is on making sure those pad ears can slide and not bind.
 

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Here’s what I found. View attachment 60207
View attachment 60205
View attachment 60206
View attachment 60204
The top of the inside brake pad seems to have been worn away more than the bottom.

I don’t know how that got started, but both pistons on the caliper move freely.

I lubed The pads and reinstalled them. The hot problem persisted.



Next I replaced the pads with new ones and test drove. The new pads seem to have fixed it, but I wasn’t out for a long drive.

I guess once the old pad started to wear unevenly it put a bind on the sliders and wouldn’t release.

The only tools I needed were the onboard tire tools and jack plus a 17mm and an adjustable wrench.

Thanks again for your help.

If the problem comes back I will replace the caliper.
How did you press the caliper piston back in? They way we used to do it was remove the reservoir cap and press the piston in with an old pad and a C-clamp. Ever since my first Trailblazer I would not use this method because it had caused issues exactly like yours, my front left caliper locked up. It was so tight that I could put it in "drive" and it wouldn't move. The way I was able to release it...I put it in drive and tapped the brake pedal very fast at the upper end of the brake travel. This would release the caliper binding but would continue to lock. I changed the master cylinder and that cleared the caliper locking but I always had issues with it when I would need to stop abruptly. I would stand on the brakes to stop from hitting something but then it would stay locked up and I would need to power off the road. I never did figure out what was causing this but then I bought a 2008 after the 2007 had a cracked valve in the head. Hope you figure it out.
 

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2002 Chevrolet TrailBlazer LTZ 4.2L
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In all the years I've done brake work, I've always used the c clamp and old pad trick. Picked up a tool a few years back at AutoZone that acts the same without having to use the c clamp due to my Impala having the brake lines in a bad place for a c clamp to press on. Never had an issue. Did the brakes on the Trailblazer when I got it and used the press back method and have had no issue.

Tool I've been using (old pad needed):
Musical instrument Guitar accessory String instrument accessory String instrument Guitar


Tool I'm looking to get (no old pad needed):
Gesture Musical instrument accessory Bicycle part Auto part Tool
 

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I keep thinking I'm going to get one of those tools. Still on the c-clamp tho.

And I've taken to loosening the bleeder while doing it and sending the brake fluid out into a drain bottle rather than shoving it back up through the brake system. I often then just let it gravity bleed for a while. For one thing, this makes it far easier to compress the caliper piston, but I'm also getting rid of old brake fluid.
 

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Discussion Starter · #12 ·
I wouldn't replace the caliper first. You pull off the bracket and clean the sh***zzle out of it to get the rust off. The focal point is the notch where the pad ears slide.

Then apply good quality brake grease to the bracket notch to hold off the rust - very thin coat. Then make sure you have new shim clips but the grease goes underneath on the bracket as rust prevention. Putting it on top attracts crap and contributes to the binding.

Your focus is on making sure those pad ears can slide and not bind.
Thanks. I just learned what rust jacking is. Here is a video I found. I think this is my problem.

 
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