[CLShifter]

For the past couple months I've been noticing the telltale shuddering and pedal-pulsing of warped front brake rotors on my Latitude with 27k miles. It seems to be noticeable when the brakes have warmed up, and is worse when braking from high speed.

Now, I'm aware that the Renegade tends to nosedive a bit on braking, so there's a significant weight shift happening, and rippled pavement at intersections is quite prominent in my area. So some of what I'm feeling is no doubt caused by that, the Renegade seems particularly sensitive to it. But I still think the rotors have a warp.

I had the dealer check it out and the tech claimed he took it on a five-mile test drive and didn't feel it. They could resurface the rotors of course, but you really should replace the pads when you do that, and the pads still have plenty of material on them. (The 27k miles on my Renegade are about 85% highway miles.) And I'll be damned if I'll pay the dealer for a brake job.

I'm not happy with the thought of warped rotors after only 27k, and I know from experience that driving with warped rotors can lead to ball joint failure. At this point I may just do the brake job and have them resurfaced myself.

 

[lovemesomejeep]

Mine were warped at 10k, FCA paid to have them turned down...they might pick yours up too?

 

[The Drifter]

For the past couple months I've been noticing the telltale shuddering and pedal-pulsing of warped front brake rotors on my Latitude with 27k miles. It seems to be noticeable when the brakes have warmed up, and is worse when braking from high speed.

Now, I'm aware that the Renegade tends to nosedive a bit on braking, so there's a significant weight shift happening, and rippled pavement at intersections is quite prominent in my area. So some of what I'm feeling is no doubt caused by that, the Renegade seems particularly sensitive to it. But I still think the rotors have a warp.

I had the dealer check it out and the tech claimed he took it on a five-mile test drive and didn't feel it. They could resurface the rotors of course, but you really should replace the pads when you do that, and the pads still have plenty of material on them. (The 27k miles on my Renegade are about 85% highway miles.) And I'll be damned if I'll pay the dealer for a brake job.

I'm not happy with the thought of warped rotors after only 27k, and I know from experience that driving with warped rotors can lead to ball joint failure. At this point I may just do the brake job and have them resurfaced myself.

yeah, if it was me, I would just park the jeep at home, put it on jackstands and take the rotors off and have the rotors resurfaced and then re-install them and re-use the pads (unless the pads are messed up).

 

[raz-0]

OK..

999 out of 1000 your rotors are not warped.

Really, they aren't. You can mike them and their runout will likely be within factory tolerances. I've been there and done that with lots of vehicles. I've had some pretty interesting discussions with someone involved with QC for the breaking system of a very, VERY popular vehicle, and the lengths they go to to ensure quality are pretty impressive, and not that far outside of the industry norms.

What you likely have is uneven distribution of brake pad material on the rotors. This is usually a combination of driver habits vs compound choices in the pads used. So if you don't change your habits, and don't change your pads, you will likely see this happen OVER, and OVER, and OVER again. I used to be that guy, and people used to happily take my money for resurfacing because yeah that will remove the deposits. Then I ran into an honest mechanic who explained this stuff when I couldn't afford new rotors and resurfacing would put them out of spec.

Just learn to properly bed/re-bed your rotors. When it starts getting pulsey, just rebed them. Boom.. back to normal.

A decent write up on the why:

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

a reasonable approximation of the how:

http://brakeperformance.com/bedding-in-rotors.php

 

[Spitfire]

Dunno about the Renegades, but if they are warped, it's sometimes more cost-effective to just install new rotors (finding a shop that can do a good job of turning them, then paying for that, plus the fact the turned rotors are thinner and may be more prone to warping again...).

 

[Ted]

What raz-0 said.
Almost certainly.

 

[kevinfourlegs]

Agree with Raz-0's comments.

 

[Spitfire]

A decent write up on the why:

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

a reasonable approximation of the how:

http://brakeperformance.com/bedding-in-rotors.php

Thanks--those are good articles. I'm willing to admit that I learned something!

 

[The Drifter]

For the past couple months I've been noticing the telltale shuddering and pedal-pulsing of warped front brake rotors on my Latitude with 27k miles. It seems to be noticeable when the brakes have warmed up, and is worse when braking from high speed.

Now, I'm aware that the Renegade tends to nosedive a bit on braking, so there's a significant weight shift happening, and rippled pavement at intersections is quite prominent in my area. So some of what I'm feeling is no doubt caused by that, the Renegade seems particularly sensitive to it. But I still think the rotors have a warp.

I had the dealer check it out and the tech claimed he took it on a five-mile test drive and didn't feel it. They could resurface the rotors of course, but you really should replace the pads when you do that, and the pads still have plenty of material on them. (The 27k miles on my Renegade are about 85% highway miles.) And I'll be damned if I'll pay the dealer for a brake job.

I'm not happy with the thought of warped rotors after only 27k, and I know from experience that driving with warped rotors can lead to ball joint failure. At this point I may just do the brake job and have them resurfaced myself.

Try Re-bedding them like @raz-0 suggested...

"-Perform 3-4 medium stops from 45mph. Slightly more aggressive than normal braking. You don't need to come to a complete stop for each pass. This brings the brake rotors up to temperature so they are not exposed to sudden thermal shock.
-Make 8-10 aggressive stops from 60mph down to 15mph. For this set of semi-stops, you want to be firm and aggressive, but not to the point where ABS activates and the wheels lock up. It's important to note that you don't come to a complete stop but rather a semi-stop (~15mph). Accelerate back up to 60mph as soon as you slowed down to your semi-stop.
-The brake pads and brake rotors are extremely hot at this point and sitting on one point will imprint the pad material onto the surface unevenly. This can cause vibration and uneven braking.
-You may notice that your brakes will start fading, and sometimes smoke, after the 6th or 7th pass. This fade will stabilize and will gradually recess once your brakes have cooled down to normal operating temperatures. Drive carefully as your brakes may feel softer for the next few minutes.
Try not to come to a complete stop and find a stretch of road where you can coast for 5-10 minutes, preferably without using your brakes."

 

[The Drifter]

OK..

999 out of 1000 your rotors are not warped.

Really, they aren't. You can mike them and their runout will likely be within factory tolerances. I've been there and done that with lots of vehicles. I've had some pretty interesting discussions with someone involved with QC for the breaking system of a very, VERY popular vehicle, and the lengths they go to to ensure quality are pretty impressive, and not that far outside of the industry norms.

What you likely have is uneven distribution of brake pad material on the rotors. This is usually a combination of driver habits vs compound choices in the pads used. So if you don't change your habits, and don't change your pads, you will likely see this happen OVER, and OVER, and OVER again. I used to be that guy, and people used to happily take my money for resurfacing because yeah that will remove the deposits. Then I ran into an honest mechanic who explained this stuff when I couldn't afford new rotors and resurfacing would put them out of spec.

Just learn to properly bed/re-bed your rotors. When it starts getting pulsey, just rebed them. Boom.. back to normal.

A decent write up on the why:

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

a reasonable approximation of the how:

http://brakeperformance.com/bedding-in-rotors.php

Since you used to be this guy, what kind of driving habits - specifically, cause these uneven deposits of pad material on the rotors?

 

[raz-0]

Since you used to be this guy, what kind of driving habits - specifically, cause these uneven deposits of pad material on the rotors?

The main things that caused it were having commutes that included highway speeds with signaled intersections. Or having really fast chunks of highway travel that dumped out in to parking lot traffic jams.

Really anything that gets the brakes hot and then you leave the brakes engaged with no motion of the rotor or limited motion of the rotor.

Different compounds do it more or less badly.

 

[The Drifter]

The main things that caused it were having commutes that included highway speeds with signaled intersections. Or having really fast chunks of highway travel that dumped out in to parking lot traffic jams.

Really anything that gets the brakes hot and then you leave the brakes engaged with no motion of the rotor or limited motion of the rotor.

Different compounds do it more or less badly.

Wow, that makes a lot of sense, I just never thought about it that way. Luckily I do not see that type of driving much, unless I go to the beach, and since I drive a manual, and as long as a stoplight is not on a hill - I will now be more inclined to take my foot of the brake at that stoplight and let the Jeep sit.

 

[kevinfourlegs]

Wow, that makes a lot of sense, I just never thought about it that way. Luckily I do not see that type of driving much, unless I go to the beach, and since I drive a manual, and as long as a stoplight is not on a hill - I will now be more inclined to take my foot of the brake at that stoplight and let the Jeep sit.

A lot of people don't think about it that way. As my Renegade has stop/start, I could sit at the traffic lights with me foot on the brake pedal, but I use the electric parking brake. In the past with my cars without stop/start I used the handbrake at traffic lights and took my foot off the brake pedal.I have been telling people to take their foot off the brake pedal and use the handbrake when coming to a standstill, especially when exiting the motorway from 70 mph to a stop for years. None of my cars have ever had warped discs.

 

[raz-0]

Wow, that makes a lot of sense, I just never thought about it that way. Luckily I do not see that type of driving much, unless I go to the beach, and since I drive a manual, and as long as a stoplight is not on a hill - I will now be more inclined to take my foot of the brake at that stoplight and let the Jeep sit.

Yeah no need to go nuts. I'd usually just try braking a bit more gently and leave some room at stops so I could inch forward so things moved around. And also just found a locale I could rebed the brakes.

 

[bwbike]

. . . I'd usually just try braking a bit more gently and leave some room at stops so I could inch forward so things moved around. . .

Totally agree with the above. When I use the brakes hard to come to a stop (rare occurrence for me), I always leave room in front of me so I can inch forward a few times so the pads will grab a different spot on the disc.