MonsoonMike

2017 Civic

I replaced my winter tires with summer tires the other day. My rear rotors are showing grooves on the passenger side. Dealership told me to grease the slide pins. I said I would do it myself when I change my tires from winter to summer.
I changed them the other day and noticed the rear slide pins are a different style then the front. I had a hell of a time removing the allen key from the pin. The allen key I used was not a perfect fit and would constantly get stuck within the head of the slide pin.
1) Anyone know the correct allen key size needed?

I added caliper slide grease to the pins. But the grease seemed to be shaved off as I placed the pin back into place on the caliper.
2) Does anyone know if these rear slide pins need to be greased at all?

ezone

2017, is it still in warranty?

mikey1

allen keys should fit perfectly, or your going to end up rounding it/stripping it

are you using SAE keys as opposed to metric?

MonsoonMike

Was likely an SAE key. I will need to buy a metric version. I just don't know wait size. Could be 7mm?

ezone

Might be Torx instead of Allen

I don't have one here to actually check though

Also...rotors can become grooved, it's not usually serious or worth worrying about. Slide pins don't cause random grooves to be dug into the friction surface.
Got pics?

MonsoonMike

I tried that last year when I first noticed it. They shrugged me off and told me to wait until my next brake service.

I will need to try again before the warranty expires. I'm just not sure they will do anything. Since rotors are a wear item.
The front rotors are perfectly smooth the back is grooved on both sides. Plus the back brakes are used less.

MonsoonMike

I'm not sure you can see the grooves from the picture. They are less than 1mm deep. Like you said it may not be anything to worry about. The fronts however are very smooth. So i figure something is not right.

ezone

Not really grooved, based only on the pic as far as I can tell.......That's just rust. Not unusual IMO.

I see this quite often, but it usually boils down to a scenario such as: the car sat for a period of time after rotors got wet, sat long enough to leave surface rust on the steel rotors --and the pads didn't scuff (clean) the rust off completely during the next drive....

How long did it sit? How much did they rust? You know rust causes the surface to raise as it swells, so
Any high spots of rust on the rotor surface can literally dig grooves into the pad material as the rotor spins and you apply the brakes, which means now those grooves in the pads can't touch the rotor in just those places to clean its surface rust, leaving those rust lines you have now.

Some of the rust you see could be in pits if it's been there a long time too, but I bet it started as a raised surface. Probably some amount of pitting is there too.


If it's not causing noise, and it's not causing vibration while applying the brakes, I would not worry much about it. Considering cost involved, I'd also suggest wait til it's due for a brake job and resurface the rotors at that time.
Or you could have the rotors resurfaced........and either replace the pads with new or try to block sand the pads until they are perfectly flat again

MonsoonMike

Your logic sounds reasonable. I agree.
No noise or vibration at this time. Yes the car did sit for a few days a few times outside.
I will wait for the pads to wear down and replace them when the time comes. As well as resurface the rotors or simply replace them. I did not know you could sand down the brake pads. That is good to know.

Thank you for your time and comments and quick replies. Much appreciated.
Cheers!

ezone

I was just thinking of a simple way to make the pad friction surfaces flat again so they can have full contact against the surfaces of the rotors (assuming they have plenty of friction material remaining, so avoiding expense of new pads if possible) , and sanding on a flat surface can be done ......but don't breathe the dust!

Rotors need to be freshly resurfaced at the same time too, so all wear surfaces start out clean and flat.

MonsoonMike

Understood.

miamirave

its a 7mm hex drive Use a ratchet and the tire iorn in your trunk to get it off. However...don't strip it please don't strip it.

MonsoonMike

2017 civic touring sedan.
I ended up replacing my rear rotors due to severe wear after 3 years. The metal of the rotor was actually flaking off. I've never had to to replace rotors this early with this much wear on any of the cars I've owned, especially with rear rotors.

The only thing I can contribute this to is the auto brake hold feature. I used it constantly since the car was purchased. It was a great feature.
I do not use this feature any more since I replaced the rotors. It's been a year and a half now and the rotors look new.

I'm not sure if the brake hold was the cause of the excessive wear on the rotors. I'm just writing this message as a cautionary note to those that use the brake hold.