Drove my 07 is 250 home yesterday and noticed a "hot" smell (hard to describe) coming from the rear passenger side. The rotor was significantly hotter than any of the others. First inclination was a caliper issue so I picked one up and some pads for good measure. After pulling off the caliper I noticed it wasn't seized. I replaced it anyways with new brake pads to see if it solved the issue. I made sure to properly lube the guide pins and contact point of pads and bleed. Just took the car out and same issue. The rotor was significantly hotter then the rest and just hot in general even after a short drive. Not really sure where to go from here. Any ideas on what else would cause this? I am going to pull the caliper back off just to double check that nothing is sticking that would cause it to rub but after that I'm out of ideas.

 

Also, just as more info...no vibration or pull when braking. All braking feels normal. No abnormal sounds that I have heard.

 

Jack up the rear end and spin the wheel, if the hot rotor side is harder to spin than the other side then your caliper is probably binding (nothing to do with slide pins). Check to see if your wheel bearing is bad on the hot rotor side. Grab the wheel at 12 oclock and 6 oclock and rock it in and out to see if there is any play in it (while it is off the ground).

You may need a new caliper.

 

Thanks I will give that a shot. Just find it odd that with the old and new caliper I put in I am getting the same issue. Hopefully it is not the wheel bearing.

 

I had a similar issue. My caliper was seized so I freed it but that didn't fix the problem. Turns out it was the piston that was stuck. End up getting new calipers.

 

Check the wheel bearing to make sure it is greased up

 

If its not the piston dragging, pretty much all that is left is the bearing.

 

Most likely is bearing issue

 

Since it's occurring in the rear, it could also be the parking brake. Check the adjustment on it to make sure it's not dragging on that side.

 

When someone says a caliper is seized. Generally that's what it means, is that the piston is seized in the caliper.

 

Really?
Because a few members I spoke with here said that it is the guide pin and rod that gets seized on our cars. Our rear calipers are very poorly designed. There is one guide pin and another guide rod on the rear and the female-end of the caliper is what rusts and runs out of grease and seized the caliper. In addition, it caused uneven wear since only the pin is sliding.

 

Sorry, I didn't mean to refer to any sort of common Lexus issue. Just clarifying the term "seized caliper". If you were talking to a mechanic who mentioned it, he would be talking about the pistons being seized in the caliper, not the slide pins. Thought it could be helpful to someone in the future as these types of things can cause confusion.

 

In general, I would agree. That's how most people would read into it they weren't familiar with the IS rear caliper design. But it is an extremely common issue that that lower slide pin on the rear calipers corrode, seizing the caliper in place. The piston is still actively working so it pushes the outer pad into the rotor under braking, but without the ability of the caliper to move it eats the outer pad and never uses the inboard pad. A seized rear caliper in our cars will almost always refer to this condition of a locked up blind pin.

 

I'm a mechanic, so I'm well aware of how disc brakes operate. As mentioned I was just giving a friendly PSA on what seized caliper refers to.

A seized rear caliper in our cars won't refer to the slide pins. However it seems some people are trying to refer to seized slide pins as a seized caliper. Perhaps you can see the confusion that can occur that I was talking about.

Not super important so it's all good. Just something that can make you sound more in the know when speaking to your mechanic, or possibly save some time on maintenance.