Rotors grooved

[wsmith3318]

I have 2013 FFH with 34,000 miles. Brakes have been much 'grabbier' lately than they have in past. When I looked at the rotors, they were all grooved up (all four of them). Pads, as far as I can see, look ok. Took to dealer who said everything was 'normal' and they did not need to do anything. Anyone else have this grooving on their rotors (its not one or two groove lines, but grooved all along the face)? Lifetime brake score is 91%.

[Easy Rider]

Yes disk rotors tend to develop ridges and groves that make them look somewhat like a vinyl record......if viewed at the right angle.

They should be very minor though and almost hard to feel if you run your finger over the surface.

 

It vaires some by model of car and pads used.

Some seem mirror smooth but many have the grooves you speak of.

 

Now that you are aware of this, look at cars you see parked.....and notice that quite a few of them probably look just like yours.

[FernMTL]

I've the same problem (vinyl looking discs) on my rears discs. They're all rusty and grooved. I do some aggressive braking now and then to try remove some rust. Makes me feel like they're not working properly, and that it just looks bad for a new car.

[Easy Rider]

If you are really concerned, have the dealer or independent shop look at them.

But it likely is perfectly normal.

 

I just went and looked at mine.

All 4 have the "vinyl record" look but feel smooth to the touch.

If it sits outside overnight and the humidity is high, all 4 will have surface rust the next morning.......which disappears completely upon moderate braking.

 

You can't, or don't want to, make the rotors bright and shiny because they work on friction and less friction equals less effective brakes.

[FernMTL]

Thanks for the info!!

[GrySql]

There is a TSB about Brakes here, although this may not be your exact issue:

http://fordfusionhybridforum.com/topic/9352-technical-service-bulletins-tsbs/?p=87972

[wsmith3318]

Thanks to all for the feedback. My grooves do not feel smooth to the touch, they are noticeably deep. I will try to get a pic and post it.

[acdii]

45000 on mine and they still look like new.

[GrySql]

45000 on mine and they still look like new.

38k on mine and all 4 rotors are smooth to the touch.

 

These cars don't use the hydraulic braking system (friction brakes) the same way a non-hybrid vehicle does, the eCVT does most of the stopping of the car. The friction brakes are only used when the eCVT can't handle the braking needs. The wheel rotors and pads should last well over 100k miles, if the system is working properly.

Below is just a small explanation of how the car stops. Of course the Friction Brakes can be applied if the drivers foot pressure on the brake pedal is high enough, as in an emergency stop scenario.

=

Regenerative Braking Mode

The ABS module determines the amount of braking torque necessary and sends that info to the PCM along with the current threshold for ABS intervention. The PCM determines how much braking torque the electric motor can provide based on the High Voltage Traction Battery (HVTB) state-of-charge and sends this information back to the ABS module. At the same time, the electric motor is switched to a generator which supplies the determined amount of braking torque. Based on the amount of braking torque the PCM can deliver, the ABS module determines whether it is necessary to apply the friction brakes or if the brake torque from the electric motor is sufficient to safely stop the vehicle.

[wsmith3318]

Attempting to attach pics of my FFH rotors. I have two rotors I took off my Honda CRV with over 100,000 miles on them and they are not grooved anywhere close to this.

[GrySql]

That is not right, your car is not working properly unless you use the brakes very hard. As I pointed out above, these cars don't use the service brakes very much unless you frequently panic stop.

My suggestion is to send a PM to our Ford Rep Meagan and get her on the case.

You might want to take the car to another Dealer for a second opinion too.

[FernMTL]

Mine's looks juste the same, even worst beacause there's half an inch around the edge of the rotor where the pads don't touch.

I'll get that check for the 3rd time on my next oil change. They've turn the rotors once last summer after 2 months of my purchase.

Wonder what's wrong, calipers maybe?

Edited April 27, 2015 by FernMTL

[GrySql]

Mine's looks juste the same, even worst beacause there's half an inch around the edge of the rotor where the pads don't touch.

I'll get that check for the 3rd time on my next oil change. They've turn the rotors once last summer after 2 months of my purchase.

Wonder what's wrong, calipers maybe?

Get the Canadian Ford Customer Service Rep involved before you visit the Dealer, Meagan will find that info for you.

[hybridbear]

Attempting to attach pics of my FFH rotors. I have two rotors I took off my Honda CRV with over 100,000 miles on them and they are not grooved anywhere close to this.

Are they grooved to the touch?

[hybridbear]

I took pictures of our rotors for comparison.

 

Ford Focus Electric

~13,000 miles

99% Lifetime Brake Score over the last ~8500 miles

~900 Lifetime Regen Miles

 

Ford Fusion Energi

~10,500 miles

99% Lifetime Brake Score since day 1

~400 Lifetime Regen miles

 

The Fusion has much less regen miles since it's used more for highway trips whereas the Focus Electric is 100% driven around the city. The Fusion rotors also look newer. I'd be curious to see if other owners could post pics along with their brake score & regen miles for comparison, particularly owners with higher miles.

Edited April 28, 2015 by hybridbear

[GrySql]

The OP's rotors have deep grooves, not smooth (Post #7).

[acdii]

45K miles

 

Front

 

Rear. Keep in mind rear brakes do more of the stopping than fronts under normal braking, so there will be slightly more wear on the rotors.

 

[FernMTL]

Get the Canadian Ford Customer Service Rep involved before you visit the Dealer, Meagan will find that info for you.

Thanks for the info! I'll take some pics tomorrow so we can compare.

[FordService]

I have 2013 FFH with 34,000 miles. Brakes have been much 'grabbier' lately than they have in past. When I looked at the rotors, they were all grooved up (all four of them). Pads, as far as I can see, look ok. Took to dealer who said everything was 'normal' and they did not need to do anything. Anyone else have this grooving on their rotors (its not one or two groove lines, but grooved all along the face)? Lifetime brake score is 91%.

Have you sought out a second opinion? Your dealer will be in the best position to assist. You can also check here for coupons on your next brake service.

 

That is not right, your car is not working properly unless you use the brakes very hard. As I pointed out above, these cars don't use the service brakes very much unless you frequently panic stop.

My suggestion is to send a PM to our Ford Rep Meagan and get her on the case.

You might want to take the car to another Dealer for a second opinion too.

Thanks!

 

Mine's looks juste the same, even worst beacause there's half an inch around the edge of the rotor where the pads don't touch.

I'll get that check for the 3rd time on my next oil change. They've turn the rotors once last summer after 2 months of my purchase.

Wonder what's wrong, calipers maybe?

Get the Canadian Ford Customer Service Rep involved before you visit the Dealer, Meagan will find that info for you.

 

Here you go! FordServiceCA.

 

Meagan

[hybridbear]

I took more pics of the Focus Electric today. My wife was driving the Fusion Energi and wasn't home from work yet when I got home this afternoon. All have tangible ridges. Some more so than others, as you can see in the photos.

 

Left front

Left rear

Right rear

Right front

Edited April 29, 2015 by hybridbear

[lolder]

The rotors on my 72 K miles 2010 are absolutely smooth to the fingernail touch. In SW FL we have no road de-icing with salt or other mixtures and little road debris or mud which might get thrown onto the rotor surfaces. Periodic torrential downpours in the rainy season June to November keeps the roads cleaner than other areas. The warm weather is also ideal for hybrids.

[Texasota]

Rear. Keep in mind rear brakes do more of the stopping than fronts under normal braking, so there will be slightly more wear on the rotors.

 

Did you mean to say front brakes? The front brakes generally perform about 65-70% of the braking while the rears provide the rest which isn’t much. This is the major reason why many cars were commonly built with disc brakes on the front and drums on the rear. The physics involved mostly explains why the front brakes do most of the braking - the car pitches forward with more downward force exerted on the front tires and a corresponding upward force on the rear tires.

 

Here are a couple of link that touch on this:

 

http://auto.howstuffworks.com/auto-parts/brakes/brake-conversion/disc-brake-conversion.htm

 

http://www.tirerack.com/brakes/tech/techpage.jsp?techid=78

Edited April 29, 2015 by Texasota

[GrySql]

FYI... The FFH Friction Brake ABS system works this way, rear brakes first. This prevents that 'forward pitch' you mention.

--

 

Electronic Brake Force Distribution (EBD)

On initial application of the brake pedal, full pressure is applied to the rear brakes. The ABS module then uses wheel speed sensor inputs to evaluate rear wheel slip. Once the rear wheel slip exceeds a predetermined threshold, the ABS module commands the HCU (Hydraulic Control Unit) to close the appropriate isolation valves to hold the rear brake pressure constant while allowing the front brake pressure to build. This creates a balanced braking condition between the front and rear wheels. If the rear wheel slip continues and exceeds a second predetermined threshold, the ABS module commands the HCU to open the dump valves to decrease the rear brake pressure and allow the rear wheels to recover. A slight bump sensation may be felt in the brake pedal when EBD is active.

If the ABS is disabled due to a DTC being present in the ABS module, EBD continues to function unless the DTC is for wheel speed sensors or the HCU. When EBD is disabled, the ABS warning indicator, the red brake warning indicator and stability/traction control indicator (sliding car icon) illuminate.

Edited April 29, 2015 by GrySql

[Texasota]

FYI... The FFH Friction Brake ABS system works this way, rear brakes first.

--

 

Electronic Brake Force Distribution (EBD)

On initial application of the brake pedal, full pressure is applied to the rear brakes. The ABS module then uses wheel speed sensor inputs to evaluate rear wheel slip. Once the rear wheel slip exceeds a predetermined threshold, the ABS module commands the HCU to close the appropriate isolation valves to hold the rear brake pressure constant while allowing the front brake pressure to build. This creates a balanced braking condition between the front and rear wheels. If the rear wheel slip continues and exceeds a second predetermined threshold, the ABS module commands the HCU to open the dump valves to decrease the rear brake pressure and allow the rear wheels to recover. A slight bump sensation may be felt in the brake pedal when EBD is active.

If the ABS is disabled due to a DTC being present in the ABS module, EBD continues to function unless the DTC is for wheel speed sensors or the HCU. When EBD is disabled, the ABS warning indicator, the red brake warning indicator and stability/traction control indicator (sliding car icon) illuminate.

Thanks for the posts, GrySql. I'm wondering if this is peculiar only to a hybrid because of the front wheel regenerative braking? Once you exceed some moderate threshold of braking the front friction brakes are going to provide the majority of the braking/stopping power.

 

Edit: Thinking about that a little more I wondering if the above makes sense?

 

On initial application of the brake pedal, full pressure is applied to the rear brakes.

 

That is not what happens with our FFH, is it? On initial brake pedal application (assuming light application) you get regenerative braking from the front. It would surprise me if rear brake application is really the first thing that happens. If we are always getting rear brake application in conjunction with the front regenerative braking, then it would seem like it would partially defeat the purpose of regenerative braking.

Edited April 29, 2015 by Texasota

[GrySql]

It is extremely difficult to answer every facet of this cars engineering, the Service Manuals do not explain each action fully. What I find I post verbatim and I look very hard before I do, I like to pass on correct info. To me, after looking at the available material it appears that the PCM uses the eCVT and ABS (and Stability Control) systems to interact and provide the vehicles braking, how this is performed is not like a normal non-hybrid vehicle with only one braking system.

The majority of the braking is regenerative, the rest is the friction brakes. My quote from the Service Manual refers to when the Friction Brakes need to be engaged, in other words stopping harder than the eCVT can handle. My take on this that is once the ABS system recognizes the need for friction brakes it happens as I posted above, rears first.

If anyone could jump in here and provide more facts, I'd appreciate it. Waldo?

 

The regenerative braking system utilizes the electric motor to recharge the High Voltage Traction Battery (HVTB) and create brake torque that is used in place of, or in combination with, the conventional friction brakes to slow the vehicle.

 

==

 

BTW, the Brake Inspection Section says this about Brake Disc's (Rotors):

 

If the diagnosis has revealed vibration in the steering wheel, seat or pedal while braking that varies with vehicle speed, machine the brake disc. Heavily scored brake discs, similar to that caused by pads worn down to the backing plate, should also be machined. In order to machine, discs must be above the minimum thickness specification.

 

If the car stops straight and true, without any of those NVH (noise, vibration & harshness) symptoms, and if the pedal is not spongy or low - things are normal.

Edited April 29, 2015 by GrySql