Failed rotors after 8 months of use

[spavel6]

My father called me last week to tell me that the Wagner Premium E-Coated Brake Rotors on the back of his 2001 Jetta are "bad". I was surprised, because I had replaced them just last December. He drives the car 4 times a week, so it doesn't tend to sit for too long. Typical maintenance regiment.

The sliders were free, and the pads moved correctly along their guides. Pads were Centric 105 Posi-Quiet Ceramic Brake Pad.

Rotor 1:

Rotor 2:

 

[4wheeldog]

Do those also work as the parking brake? Because those really look like someone drove a lllloooonnnngggg way, with the parking brake partially engaged.

 

[Bottom_Feeder]

I'm not seeing how that's a problem with the rotors. Something else is awry and the rotors paid for it.

 

[spavel6]

Originally Posted By: 4wheeldog
Do those also work as the parking brake? Because those really look like someone drove a lllloooonnnngggg way, with the parking brake partially engaged.


Yes, parking brake is integrated into the caliper.

 

[Chris Meutsch]

Originally Posted By: Bottom_Feeder
I'm not seeing how that's a problem with the rotors. Something else is awry and the rotors paid for it.


This. The pads aren't engaging onto the rotor surface properly. Those look corroded from non-use.

 

[spavel6]

I guess the question is, non-use or does this look more like sticking caliper pistons?

 

[Bottom_Feeder]

I'd say bad calipers, maybe a hydraulic pressure issue?

What do the pads look like?

 

[4wheeldog]

Originally Posted By: spavel6
I guess the question is, non-use or does this look more like sticking caliper pistons?


I have never seen non use turn a rotor blue. If the color is correct, and not a product of some odd photography gremlin, those things were engaged until extremely hot. I am betting that it was driven with the parking brake on.

 

[Dan55]

OE Pad is Semi Metallic and looks like they are not used.

 

[eljefino]

I've seen rear rotors like this. They get like 15% of the braking load. Wonder if your dad is easy on brakes. You could also have a bad proportioning/ load levelling valve. Try jacking it up when you fix it and putting a stick on the brake pedal to see if you can rotate the wheel by hand.

 

[spavel6]

Originally Posted By: 4wheeldog

I have never seen non use turn a rotor blue. If the color is correct, and not a product of some odd photography gremlin, those things were engaged until extremely hot. I am betting that it was driven with the parking brake on.


I'll check when I get home but I think the blue is just an artifact terrible iPhone photo quality.. I hadn't noticed that when I took them off.

 

[spavel6]

Originally Posted By: Bottom_Feeder

What do the pads look like?


Pads had the inverse ridges to the rotors. But were evenly worn inside and out, and did not have any other irregular wear..

 

[salv]

Pads are hanging up in the slides and not closing on the rotor properly when braking. The pads aren't clearing superficial rust and debris from the rotors face, which in turn is allowing the surface corrosion to pit into the metal.
Brake slides need to be cleaned with a dremel tool to eliminate rust and burrs from the surface that the pads ride. A high temp brake grease should be used,, not anti-seize.

 

[DoubleWasp]

I'm going to go with caliper problem. Frequent use of a rotor should leave its surface uniform. Rotors look untouched in most of the braking area.

 

[A_Harman]

Maybe the caliper pistons are stuck on their bores. Rear brakes on FWD cars don't do much work, and after 14 winters in the northeast, they may not be doing anything. It looks like only the inside pads are contacting the rotors, and only on about half their width, judging from the pictures.

 

[Nick1994]

Rear brakes sticking on A4 VWs is old news. That's what happened.

 

[zzyzzx]

Obligatory Chinese rotor picture:

 

[The Critic]

On a VW of that vintage, be sure to double check the parking brake cables.

 

[badtlc]

I don't think rear rotors look like your chinese pictures.

 

[Tegger]

Originally Posted By: A_Harman
Maybe the caliper pistons are stuck on their bores

Having seen this sort of thing before, I believe the above quote to be the issue.

I'll bet the pistons have corrosion on them. Now that the pistons are back in their bores on account of the pad-change, that corrosion is causing the piston to stick and drag.