Created on: 2019-10-05
1A Auto shows you how to diagnose smelly hot brakes and some common causes of seized, or frozen brakes! Check it out!
Jack Stands
Infrared Thermometer
Complete Hex Socket Set
Complete SAE Socket Set
Ratchet
Floor Jack
Complete Metric Socket Set
So I'm driving this car the other day and as I'm driving it, I'm stuck behind a truck and I could smell this burning smell. It smelled a little like charcoal, but definitely some type of burning, rubbery, charcoaly smell and I let the truck go further up thinking that the smell would go away and it actually started getting worse. So what I did was pulled over and I could see my right rear wheel was smoking.
So I have one of these infrared thermometers. What I can do is go around to each rotor and just check and see where they're at. Now I can see this rotor is actually blue. So I can tell that this one is hot. Right now it's at about 300 degrees, which is extremely hot for a rotor. If we go check some of the other rotors, it's at about 120 which is still pretty hot, but not nearly as hot as 300. So I knew it was time to go back to the shop and check it out.
So we got the vehicle back in the shop and it's up on the lift. The caliper isn't so frozen that this wheel won't spin. One thing you can do is you could actually put the vehicle up on a lift. You could pump the brake pedal, push on it really hard and then go around to each wheel. Try to turn it and see if you find one wheel is harder to turn than the other. You may have a caliper problem, caliper sticking problem. Another thing you may want to check to see if you have a sticky caliper is if you find a wheel that has a lot of brake dust on it, if all three wheels are pretty clean except for one, you might have a sticky caliper. So you might want to check it out. Before we take this apart, I can still feel heat coming off the wheel. Don't want to touch any of these components. They're extremely hot. I'm going to let them cool down before I take anything apart.
Now I'm going to take the wheel off. So now obviously we can see the rotor got really hot. See how it's blue right there? If you looked at another rotor, it wouldn't be that blue color and red or pink right there. So this rotor needs to be replaced and because the pads got really hot, those have to be replaced as well. So on the back side of this caliper, this caliper has the parking brake assembly integrated into the caliper. So the parking brake cable comes in over here, attaches to this lever right here and there's a spring right here. If you look at this spring, this spring is extended, which it should not be and there's a little gap right here. This lever should be right up against this stopper right here. If you check it, compare it to the other side, the other side is normal.
So now we need to determine whether it's just the parking brake cable or if it's the caliper lever itself. So I disconnected both ends of the parking brake cable on the passenger side because that's the side that was seizing up. The driver's side was not and when I pull this cable, it is extremely hard to force this back in. This should move pretty easily and it's not. So somewhere in the cable, it is probably rusted and corroded and that's what's causing it to bind up. So this cable needs to be replaced. Now, if this cable was moving freely, what you would want to do is take some big pliers, see if the levers move freely and they're not binding up at all. So in our case, it was just the cable, not the caliper. So if that wasn't your problem, here's some other things that it could be.
The brake hose could be internally blocked, causing fluid to go into the caliper, but not releasing. The caliper piston itself could be seized up and causing the brakes to stick. This particular caliper has a special tool that is required to compress the caliper piston because of the integrated parking brake cable. So you'd need that special tool and make sure that that compresses properly. These caliper slide pins could be frozen. So you want to double check those, make sure they're not seized up. These brake pads could be stuck in the brake caliper bracket due to rust or other contaminants. Because the brakes got so hot back here, what we're going to be replacing is the rotor itself, the pads. We're going to replace the caliper because the caliper got really hot and there's internal seals and you don't know. They may have been compromised, plus the caliper hose itself and the parking brake cable. All right, so there we go. I got all of those parts in. Everything feels great. No more sticky caliper. Now I can drive this with confidence.