The mystery "failure"

[OVERKILL]

Last night, my wife and I went out for a nice romantic drive in the Jeep, it being Family Day here in Canada.

About 30 minutes into our drive and it felt like the road was getting rough. Like I was driving on washboard. This got worse. I hit the gas to see if that had an impact. Nope. Hit the brakes, it went away almost completely, then came back shortly after I let off. A change in road surface did not have a change in the feeling. Slowing down, it turned into more of a thud thud thud.

Pulled into a small town and parked. All the wheels smelled and looked fine except for the left front, which smelled hot, but the brake calliper was not hot.

I called roadside and had the vehicle flatbed'd to the dealership.

Three test drives, totalling several hours today, they've been unable to reproduce the issue, so, I'm off to pick it back up now...


I was originally thinking wheel bearing. However, that wouldn't magically go away. I wonder if I got a rock jammed in the brake pad? Though I would have expected that to make noise?

Any ideas?

 

[kschachn]

My BMW did that when it had a sticking caliper piston in the front. I stuck my hand inside the wheel too and it wasn’t that hot but when I took it apart it was obvious.

Not saying it is the same but it sounds similar.

 

[OVERKILL]

My BMW did that when it had a sticking caliper piston in the front. I stuck my hand inside the wheel too and it wasn’t that hot but when I took it apart it was obvious.

Not saying it is the same but it sounds similar.

These are 8 piston callipers so that could be exciting, lol.

They also quoted me a brake job at $3,000 because the front pads are getting low. It has 24,000km on it.

Was your issue transient? Because this appears to have been, at least so far.

 

[brianl703]

I was originally thinking wheel bearing. However, that wouldn't magically go away. I wonder if I got a rock jammed in the brake pad?

Seems like that would've left a mark on the rotor.

 

[OVERKILL]

Seems like that would've left a mark on the rotor.

Yeah, unless maybe it was a chunk of rubber or something? It didn't FEEL like the brake was dragging, which I would have expected it to if it was bad enough to cause this issue. I could be wrong though.

 

[kschachn]

These are 8 piston callipers so that could be exciting, lol.

They also quoted me a brake job at $3,000 because the front pads are getting low. It has 24,000km on it.

Was your issue transient? Because this appears to have been, at least so far.

Yes. It happened mostly in the rain which seemed weird but yes it was transient.

 

[brianl703]

Yeah, unless maybe it was a chunk of rubber or something? It didn't FEEL like the brake was dragging, which I would have expected it to if it was bad enough to cause this issue. I could be wrong though.

On all the occasions where I've dealt with a dragging brake, it was obvious from the heat radiating off the rotor. Just get your hand near that rotor and you could feel it. No thermal camera needed.

 

[OVERKILL]

On all the occasions where I've dealt with a dragging brake, it was obvious from the heat radiating off the rotor. Just get your hand near that rotor and you could feel it. No thermal camera needed.

And that's the thing, there was not a massive amount of heat coming from the rotor, and the calliper itself was not hot, but something smelled very hot.

 

[SwampSurvivor]

That's a sticky caliper piston. Usually they'll seize up in the bore and when you let them sit a while, they'll cool back down and work for a while.

As someone who has a 99-04 Ford superduty, I go through this on all 4 every two years.

 

[OVERKILL]

That's a sticky caliper piston. Usually they'll seize up in the bore and when you let them sit a while, they'll cool back down and work for a while.

As someone who has a 99-04 Ford superduty, I go through this on all 4 every two years.

Interesting.

When I've experienced that before, I've never had this thumping/vibration, just the feel of drag and the calliper and rotor both being very hot and stinking. But, those have been on conventional floating brakes with one-piece rotors, while this has fixed 8-piston callipers with 2-piece rotors.

 

[pantygnome]

All the padlets and hardware in place? Maybe one was vibrating? Forever ago, my parents Dodge Magnum had a recall for improperly torqued caliper mounting bolts...might be worth a check (though Im guessing they would have checked that already)

Notice anything different with the brake pedal when it happened then stopped? When I had frozen caliper(s) up front, the first press of the pedal was mushy but after that it got better. Next time I had to hit the brakes, the process repeated.

 

[kschachn]

Interesting.

When I've experienced that before, I've never had this thumping/vibration, just the feel of drag and the calliper and rotor both being very hot and stinking. But, those have been on conventional floating brakes with one-piece rotors, while this has fixed 8-piston callipers with 2-piece rotors.

Thumping vibration is exactly what it did on my BMW.

Owning that car was a good lesson in "if it can happen, it will happen."

 

[Klutch9]

Last night, my wife and I went out for a nice romantic drive in the Jeep, it being Family Day here in Canada.

About 30 minutes into our drive and it felt like the road was getting rough. Like I was driving on washboard. This got worse. I hit the gas to see if that had an impact. Nope. Hit the brakes, it went away almost completely, then came back shortly after I let off. A change in road surface did not have a change in the feeling. Slowing down, it turned into more of a thud thud thud.

Pulled into a small town and parked. All the wheels smelled and looked fine except for the left front, which smelled hot, but the brake calliper was not hot.

I called roadside and had the vehicle flatbed'd to the dealership.

Three test drives, totalling several hours today, they've been unable to reproduce the issue, so, I'm off to pick it back up now...


I was originally thinking wheel bearing. However, that wouldn't magically go away. I wonder if I got a rock jammed in the brake pad? Though I would have expected that to make noise?

Any ideas?

Strange. Last year I had a sort of similar issue on one of our vehicles. In our case, I KNEW it was brake-related because not only was one wheel getting hot but you could also smell hot brakes, car would lug when accelerating, pull under braking, etc. It would also make a washboard-esque noise occasionally, more of a cyclical humming at speed. I thought it was a sticking caliper but it was actually a collapsed brake line in the front (the flexible portion). I only found this out because I replaced the caliper to no avail. The brake line had no visible damage, but I'm guessing that internally it was collapsing when the brake pedal disengaged and the master cylinder went to draw back the fluid in the lines. I replaced it and all is well.

 

[SammyChevelleTypeS3]

Last night, my wife and I went out for a nice romantic drive in the Jeep, it being Family Day here in Canada.

About 30 minutes into our drive and it felt like the road was getting rough. Like I was driving on washboard. This got worse. I hit the gas to see if that had an impact. Nope. Hit the brakes, it went away almost completely, then came back shortly after I let off. A change in road surface did not have a change in the feeling. Slowing down, it turned into more of a thud thud thud.

Pulled into a small town and parked. All the wheels smelled and looked fine except for the left front, which smelled hot, but the brake calliper was not hot.

I called roadside and had the vehicle flatbed'd to the dealership.

Three test drives, totalling several hours today, they've been unable to reproduce the issue, so, I'm off to pick it back up now...


I was originally thinking wheel bearing. However, that wouldn't magically go away. I wonder if I got a rock jammed in the brake pad? Though I would have expected that to make noise?

Any ideas?

Bearing as you say would not fix itself. Plus you can usually hear the high pitch of the bad bearing. Maybe? Something (piece of tiny road debis stuck in the brakes) except that should have cut into the rotor face. Unless its in a tight spot that cant be seen.
Usually the wash board feeling happens when applying the brakes on a vehicle with a warpped rotor or a damaged pad. Could it be an electronic gremlin that has to do with the vehicle stability system or anti lock brakes kicking in and out?

 

[brianl703]

My 1998 Nissan Frontier had a problem with sticking front brakes when it was still my dad's about 3 years ago.

I just decided to replace both front calipers, pads, and hoses and fully bleed the brakes.

That fixed the problem.

 

[The Critic]

I just decided to replace both front calipers, pads, and hoses and fully bleed the brakes.

That fixed the problem.

Sorry, I could not resist.

 

[brianl703]

View attachment 141504
Sorry, I could not resist.

Way I figured it, both hoses were 22 years old, at least one of the calipers had a problem, and at $45 each, it wouldn't take too much time farting around before it would be easier and cheaper just to replace the calipers.

There's also the idea that if one of the 22 year old calipers has a problem, the other isn't too far behind in also having the same problem. (I really didn't want to have to deal with the same problem on the other side later on...)

If it were a 3-year-old vehicle it'd be a different situation.

 

[twouvakind]

"They also quoted me a brake job at $3,000 because the front pads are getting low. It has 24,000km on it".

I think I just threw up a little in my mouth.

 

[OVERKILL]

All the padlets and hardware in place? Maybe one was vibrating? Forever ago, my parents Dodge Magnum had a recall for improperly torqued caliper mounting bolts...might be worth a check (though Im guessing they would have checked that already)

Notice anything different with the brake pedal when it happened then stopped? When I had frozen caliper(s) up front, the first press of the pedal was mushy but after that it got better. Next time I had to hit the brakes, the process repeated.

Yeah, as far as I know. Things aren't super accessible because of the fixed nature of the callipers. Brake pedal felt fine.

I have the vehicle now and it feels fine. Both callipers feel the same temperature, as do both rotors after lots of stopping. No smell, no vibration. Guess we'll see if it comes back?

 

[OVERKILL]

Bearing as you say would not fix itself. Plus you can usually hear the high pitch of the bad bearing. Maybe? Something (piece of tiny road debis stuck in the brakes) except that should have cut into the rotor face. Unless its in a tight spot that cant be seen.

I was thinking maybe it was possible that something jammed between the calliper and pad?

Usually the wash board feeling happens when applying the brakes on a vehicle with a warpped rotor or a damaged pad. Could it be an electronic gremlin that has to do with the vehicle stability system or anti lock brakes kicking in and out?

Would be weird for it to only affect the one wheel though, and no indication that the ESC or TC were engaging, and I was able to hit the gas and accelerate hard and the vibration persisted.

What's interesting is that this didn't occur after a brake application. I had been driving for like 15km at around 90-ish km/h (~55mph) when it started happening out of the blue.