Front right brake gets hotter than front left

The other day I noticed some brake stench when I parked my car - the kind of smell that's usually a reward for some aggressive driving. However, I hadn't been speed racing, just doing my normal commute.

 

I walked around the car, and noticed the smell was strongest the front right. Also, the front right rotor was significantly hotter than the front left.

 

This has been going on for a few days now, and it's kind of inconsistent - after some drives I don't smell brakes at all, and both rotors seem approximately the same temperature. After other drives the front right is noticeably hotter.

 

The car doesn't pull in either direction if I brake with hands off the wheel.

 

So, I'm assuming the pad is dragging for some reason. Can somebody walk me through the diagnostic steps?

 

I had a stuck caliper on my miata once, which made a horrendous noise, and was caused by rust. There's not any noise on the legacy, so I'm guessing it's not as serious?

 

Edit - It does seem like this has come on with the cold weather,and I just saw this in the what did you do to your 4th gen thread:

Most people don't understand that a LOT of grease is much worse than a little. What you experienced was called 'hydraulic resistance' and because the grease will not compress, it becomes as a hydraulic cylinder and the grease forces the bolt back out, or in your case the caliper in.

 

For years, I've used grease as a pressing agent to remove bushings from captive pockets and it works very easily and quickly. You simply fill the center hole of the bushing to the top with grease, insert a shaft that fits snugly in the center and smack it with a hammer. Add more grease to refill the hole, shaft, smack, and repeat until the bushing comes out.

 

This is the standard accepted method for removing clutch pilot bushings out of the ends of crankshafts but it works on just about any bushing. If it's something that's REALLY stubborn AND you can remove the part from the vehicle, you can fill the center with grease, insert the shaft, and then use a hydraulic press to force the shaft into the center slowly and you'll be able to see the bushing begin to move.

 

Light grease on anything with a rubber seal, light grease on anything that goes into a sealed pocket, HEAVY grease on something that has a vent in the pocket (ball joint is a good example as the grease can exit out the top of the pocket) because it will help to seal up the opening and protect what is inside.

 

 

Maybe it's a little overgreased, and the cold weather thickened up the grease enough to cause a similar issue to cww's problem?

I think you're on the right path. It could be a stuck caliper, pad stuck/hanging in the carrier, or bad brake line. I would get the front of the car up in the air and check for drag on the brakes. If one wheel drags when you check, pull the wheel, check if the pistons can retract into the caliper, check that the pads move in the carrier. I don't have a good way for you check the lines, but if the pads won't move back into the caliper, it's either the caliper or the line(s).

this sort of problem is usually the lower slide pin sticking, the lower piston sticking or the rust under the stainless steel rails the pads slide on.

 

undo the lower caliper mounting bolt and swing the caliper up. if the pads can't move, pop them off and the stainless bits. remove rust, grease and re-install. with the caliper swung up, check the lower pin. then slide the caliper assembly around to check to upper pin. remove and grease as needed. make sure you use the right grease for the lower pin as it has a little rubber insert around the pin which can swell up and cause you trouble a day or two later. if the slide pins are ok, swing the caliper back down but don't bolt the lower pin. apply the brakes and release, now check if the rotor is free to turn. if it isn't the pistons are sticking in the bores. most likely the lower one.

 

the seal kit is 30-40 bucks depending on where you live. the front kit has parts for both sides, so don't buy two. it doesn't include the crush washers. the dealer washers and NAPA ones are the same diameter, but NAPA only has slightly thicker ones (at least around here). both have worked for me. you will want a bore hone and blunt dental picls as well so you don't waste too much time cleaning things up. plan on 20 mins per caliper if you have the hone, much longer if you don't.

 

also, if one caliper is starting to stick because of rust, the other one isn't far behind. do yourself a favour and service the pair.