Is my Caliper broken?

Hey everyone how’s it going. So I decided to do my own maintenance recently. The first job that I’ve gotten is a malfunctioning caliper. I heard some concerning noises from my wheel. I took it off and found that my brake pads were very unevenly worn out. The outside one had at least half life and the inside one was worn out in a tapered fashion( thickest at the bottom none at the top). So I quickly diagnosed that its a stuck/ not lubricated guiding pin causing this issue as I had a tough time taking it off (top one). I unscrewed the top pin and somehow pulled it out, lubed it up, cleaned the housing, tested it a couple time and thought it was good to go. I replaced the brake pads. Now this is where something weird happened and I don’t know enough about calipers to know if this is normal. I wanted to lube the bottom pin too. While trying to install the brake pad i realized that the bottom pin just slid out (I did not unscrew it, it was still screwed on to half of the caliper (the part that comes off when you take both pins off) and I am not sure if that normal? The part that you can normally flip/slide open by taking off one pin to replace brake pads, came complete off with the pin still screwed into it. Is this normal? Is my caliper broken?

At no time did you describe the vehicle you’re talking about.

On some vehicles, that’s normal.


Did this “problem” happen on both calipers, right and left? Or only on one side? Have you only done one side, or both?

Sorry it’s a 2010 infiniti g37x coupe.

I am replacing both sides. The other side the bottom guide pin is stuck (unscrewed and easily removed the top), I’m working on getting it free (I have actually unscrewed it and its still not coming out so I don’t know if it’s normal for it to just slide out).

Sketch out on a napkin how the bottom pin is configured on the stuck side, while it is still stuck, then you’ll know how the first side is supposed to be re-installed. Your diagnosis of the caliper slides not sliding is a good one, and is probably why you are getting those weird wear patterns on the pads and other symptoms. i’d recommend you secure the service data for pad replacement and caliper service for this job btw. It should be in a Haynes or Chilton manual, or may be available by googling. No need to guess when somebody has already figured it out and published it.

If the top and bottom pins work the same way then, I just have to unscrew it and then slide it out. But the issue I have is the bottom pin on one just came out without me unscrewing anything. And I am unable to check if this is normal on the other side because the bottom pin is stuck, even unscrewing it isn’t helping. The top pins on both sides I was able to unscrew and then slide them out. I am following a guide, but they all seem to unscrew both pins and then slide them out. My issue is the bottom one just slid out while it was still screwed in (and the pin is still screwed to the caliper so its not a worn out thread). The service manual doesn’t talk about whether that’s normal or not.

If you are working on the front brakes and they are single piston calipers you only need to remove one caliper pin, rotate the caliper 90 degrees and slide the caliper w/pin off the bracket.

If you could post a picture we might know if you are working on the front or rear and if your car has dual piston calipers.

The G37 will have the two small caliper pin bolts that hold the caliper onto the bracket… Slide the caliper up and out and remove the shoes. Then you need to check you slider pins…this is what those two small bolts were threaded into. More than likely no one has ever greased these poor items and one or more are locked up and in your case it sounds like you lost one of those two small bolts that hold the caliper to the slider pins. There are also two much larger bolts that hold the caliper bracket onto the spindle.

Sometimes you can free the sliders and grease them and they work fine…other times you need to buy new or rebuilt cals.

I apologize I didn’t give a lot of details.I believe this is the case, I am working on the rear calipers and they are single piston calipers.

I will test and confirm if it only comes off when its 90 degrees. I didn’t notice that.

When you say pin bolts I’m guessing you are talking about the small bolts, I do not see those at all. The large ones you see in this picture are not threaded where as mine are, so I just unscrew it and pull it out.

The slider pins are the long ones. Thats the one you have problem getting out, right? If they are frozen,use some PB Blaster and a propane torch to get it out.

So I left it screwed on to the caliper and was able to get the slider pin out similar to how I did on the other side, just had to wrestle with a bit. I guess it’s not broken it’s just how the caliper is designed. I cleared the rust, cleaned and lubed all the moving surfaces (not the braking face obviously). Pins slide in and out easy, pads move side to side easy, and I put it all back together, and everything seems good so far. Ill check on the weekend to see if the pads have uneven wear. Thanks for you input everyone.

Good for you for getting it sorted out. Where there’s a will there’s a way.