Help with brake question

[Sierra048]

We just took my wife's 2014 Nissan Frontier from Cherokee, NC to Gatlinburg, TN. The Frontier is three years old and just turned 30k on the odometer. Approximately 70% of these miles were highway miles.

My question: as we were coming down the mountain heading to Gatlinburg, the Frontier developed a harsh shimmy/vibration when braking on down slopes. I checked the brake pads just last week when rotating the tires and they looked virtually unused, with plenty of pad left. I'm thinking maybe the rotors got a little hot. If so, would this be normal behavior, or a reason for concern. Would this cause the the vibration? Also, once out of the mountains, braking returned to normal. Any ideas? Opinions? Or, is this something I should be concerned about.

 

[buck91]

Sounds like the rotors aren't perfectly true; whether its high spots or out of round or what ever I couldn't say. But its good that they are only acting up when hot. If it were me I'd try turning them but would expect to replace after the vibe returned.

 

[LeakySeals]

I don't think metal rotors warp. I think the pads get hot and glaze over the rotors in random areas. So when you brake its not even, feels like a vibration when you slip on glaze at high speed/quick rotation. That might fit your description. Your not braking as hard after the mountains, so the vibration feels like it went away. Because you have enough grip on the glazed rotors for the current conditions.

 

[Thax]

Sounds like the rotors got a little hot. I'd suggest having the rotors turned and to flush the brake fluid. Flush the fluid due mileage/age and the fact that the fluid most likely got very hot during the mountain descents.

 

[Rand]

might just need to sand the rotors they could have some pad deposits.. esp if you had to stop and sit at a traffic light after they got hot.

I would also consider flushing the brake fluid as it will absorb moisture and about every 3 years is recommended esp. for moist/humid areas.

 

[40w8]

I have a RX8 Mazda that had this resin that hung around on brakes for a few years, and would do what you describe.

I wasn't driving car hard enough to bed in brakes until track day a year later.

I wouldn't do anything except brake harder to burn the pads and rotor in, since pads are still ok.

 

[Sierra048]

Thanks for the input. Several mentioned replacing the brake fluid. That was just done along with the rear diff fluid, ATF and power steering fluid. We'll be heading home Saturday so I'll get a chance to see if this happens again. The only other variable I didn't mention before was the roads were wet from rain. Could that have been a factor? Oh well, I'll find out Saturday. Thanks again and I'll post how it went.

 

[ZebRuaj]

We had a rental Dodge Caravan that did this while we were coming down the San Gabriel Mountains from LA to Fresno. Pulled off and gave everything a visual once-over, then just played it safe the rest of the way down. Symptoms disappeared when we got to the valley. Called the rental shop to covered my butt, but I doubt they did anything about it after we turned the van back in.

 

[LeakySeals]

Originally Posted By: Sierra048
The only other variable I didn't mention before was the roads were wet from rain. Could that have been a factor? Oh well, I'll find out Saturday. Thanks again and I'll post how it went.

could have been the ABS system

 

[40w8]

+1 ^

 

[spasm3]

If it was not the abs activating, then I think anytime you get the rotors hot, this will return.

I think you have some pad deposits, and that thickness variation shows up when the rotor is hot. I would try a few hard cold stops and see if that helps. If not, better pads and new rotors.

I run premium pads and cheap rotors. Good pads tend not to transfer as much material to the rotors when hot.

 

[Sierra048]

Originally Posted By: spasm3
If it was not the abs activating, then I think anytime you get the rotors hot, this will return.

I think you have some pad deposits, and that thickness variation shows up when the rotor is hot. I would try a few hard cold stops and see if that helps. If not, better pads and new rotors.

I run premium pads and cheap rotors. Good pads tend not to transfer as much material to the rotors when hot.


To keep this thread going until I get home, any rotor/pads suggestions? Five years ago I used Wagner Thermo Quiets on the Xterra which was identical to what's on the Frontier. The Xterra had 80k miles and the facory pads still had wear left but I did them because after eight years on the road I thought it might be time and I used a Wagner rebate and Advance Auto discount. A large part of those miles were highway miles. The Wagners appeared to do a decent job. Rotors were good so I just roughed the surface up with some emory cloth. Any opinions on the Advance/AutoZone/O'reilly house brands, both rotors and pads?

 

[Sierra048]

OK. We made it home and the brakes pulsated/vibrated coming down the mountain. Roads were dry. Once on level ground braking returned to normal. I've decided to just inspect the brakes at the next tire rotation and maybe rough the rotor surfaces up with some emory cloth. Thanks for allthd input and suggestions.

 

[buck91]

Originally Posted By: Sierra048
Originally Posted By: spasm3
If it was not the abs activating, then I think anytime you get the rotors hot, this will return.

I think you have some pad deposits, and that thickness variation shows up when the rotor is hot. I would try a few hard cold stops and see if that helps. If not, better pads and new rotors.

I run premium pads and cheap rotors. Good pads tend not to transfer as much material to the rotors when hot.


To keep this thread going until I get home, any rotor/pads suggestions? Five years ago I used Wagner Thermo Quiets on the Xterra which was identical to what's on the Frontier. The Xterra had 80k miles and the facory pads still had wear left but I did them because after eight years on the road I thought it might be time and I used a Wagner rebate and Advance Auto discount. A large part of those miles were highway miles. The Wagners appeared to do a decent job. Rotors were good so I just roughed the surface up with some emory cloth. Any opinions on the Advance/AutoZone/O'reilly house brands, both rotors and pads?



I've used autozone and oreilly's house brand brake pads on a couple of "beater" vehicles before. Typically for a year or less (before selling the vehicle). Never had any complaints.