brake odor

mark sr

Member
I got a distinct brake odor when driving my jk this morning. While my nose couldn't pinpoint the odor, the left front and right rear wheels were hot to the touch. Would this be a traction control issue? How do you determine/fix or is it something else?

2010 jk, 67k, no codes
 

I believe if it were traction control the ABS would be kicking in and out.
Being they are hot they may be the issue. They may also be the only two working and the other two frozen. The only way to tell is to jack up the front and try to spin the tires then let someone apply the brakes. Engine on or off. I'd do it off so the other person can hear you.

Repeat in the rear. Also consider the rear parking brakes.


JPNinPA
Using Jeepz.com app
 
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I haven't had time to jack it up and look yet, hopefully when I get back from my doctor appointment in the morning. My wife's brother fell and broke his kneecap a couple of weeks ago, he gets out of rehab friday but then they will have to redo the surgery on tuesday, busy busy busy but I digress.

The rims on the left front and right rear were almost too hot to touch so I believe they are dragging. If it was just one I'd suspect a bad caliper but it seems odd that those two calipers would go out at the same time. It brakes evenly, no pulling to right or left. I rarely use the parking brake so I doubt that is the issue. Hopefully I'll know more when I get time to jack it up.
 
If you pull the wheels compare the pad thicknesses and see that they are evenly worn and no wedge shaped pads.


Regards,
JPNinPA

Sent using TapTalk
 
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I intend to although I don't know that it will show much difference as I only drove 15-20 miles after I started smelling the brakes. It still has the factory pads on the front but I changed out the rear pads at 55k.
 
The left front wheel is stuck, takes a bit of force to move it with tire on, impossible with it off. Both rear wheels spin about the same although the left rear emits a brake odor when you spin the wheel. The odor is also present in the cab but not really noticeable at the left front. The front pads only have a little life left in them.

I'm inclined to replace the left front caliper [along with pads] but I hate to replace a part based on guess work.
 
So on the front is the pad wear the same between both pads on one side? How about from the left to right of the vehicle?
Also when someone actuated the pedal do the calipers clamp?

You could put new front rotors and pads on and in the process assess each caliper.
Then the backs while bleeding the brakes...

JPNinPA
Using Jeepz.com app
 

I didn't have any help so I didn't check with the brake pedal pressed. Pad wear is similar on both sides.
I don't know if I'll have time to do anything with my jeep tomorrow as we have to pick my wife's brother up at rehab and help him get settled in his apartment, get him grocerys, etc.
 
When I was first getting aquainted with 'Black Betty' I noticed this kind of odor too. Once getting into it the wheel bearings were wearing funny and after several iterations of bearings and insertion depths in that AMC 20 I gave up and had a D44 built for her. After getting the 20 on the ground it became apparent that the axle tubes were bent, which when this axle was mounted it was impossible to discern.

I hope your path is easier and cheaper!
 
For the most part my jk has an easy life. I don't go off roading but I live in the mountains with a long driveway that winds up the north side of the hill. That is my main use for 4 wheel drive. My jk does better in the snow/ice than any 4x4 I've ever owned including a 69 bronco with posi.

Hopefully I'll have more time come mid week. My truck driver son should also be back in town to help me ;)
 

If the wheel is hot to the touch you most likely have a seized brake caliper. You can often remove the caliper, run the piston in with a c-clamp, and reassemble. It'll likely seize again someday until replaced.
 
The left front caliper is seized but I think the left rear might have been too. That makes me second guess whether or not the caliper is the culprit.
 
Was it the piston or the glides? Many forget to clean and lube the glides each time they check or replace the brakes. If water gets past the boots on the glides they will rust the caliper in place.


Regards,
JPNinPA

Sent using TapTalk
 
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Everything has been pretty hectic around here and I've not had time to look at my jeep but hopefully tomorrow I can get after it with my son's help.
 
Once removed the brake caliper seemed ok but it was just a tad stiff and since i didn't know what to do - I went ahead and replaced it. That seems to have fixed it although I am still at a loss as to why the right rear got hot and then seemed to fix itself. Still need new pads [out of stock] although the factory ones still have a little life left. Keeping my fingers crossed that my brake issues are over.
 
Just a shot in the dark, but is the front caliper and the rear caliper that was siezed on the same break line ? It seems to me that a long time ago I had a problem where as the fluid in the break line had heated up for a reason I cannt recall, possibly it was a wheel bearing went bad causeing the wheel to get hot ,resulting in heating of the brake fluid in the line makeing the calipers close. Once it cooled down the breaks was fine. I suspect a bad wheel bearing may be the root of the problem.
 

On the rear, at a minimum grease the glide shafts and bleed all the way around.

Checking wheel bearing is easy using the shake method before or after bleeding.


JPNinPA
Using Jeepz.com app
 
It seems to me that a long time ago I had a problem where as the fluid in the break line had heated up for a reason I cannt recall

A long time ago I had brake fluid that got extremely hot [exhaust issue] and it resulted in no stopping power.
It does seem like the left front and right rear issue should be related.
 
If you smell a funky burning odor when you hit the brakes, you have a problem. Overheated brakes smell quite bad and are a dangerous situation. If your brakes are smoking, you are burning the pads. Overheated pads develop a glaze on the surface that is slick, and your braking performance will be be greatly reduced. This is a component of brake fade as discussed earlier.
 

The brake odor is gone. If it had just been the front left brake sticking I wouldn't have thought twice about changing out that caliper. What confused me was the right rear also sticking but it seemed to fix itself by the time I worked on it. I've only drove the jeep about 50 miles since I replaced the left front caliper but every thing seems to be back to normal. I'm still keeping an eye on it just to be safe.
 
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