Disc brake pad orientation

[LD1]

May sound like a stupid question but gotta ask for reasons I'll explain later.

Is there a technically correct orientation to installing disc brake pads. Meaning is there a way to "technically" put them on backwards or upside-down with regard to anything. Like squeaker on top or bottom? Or a certain rotation direction the pad operates best at like a belt sander belt?

I am used to getting 4 identical pads in a box, and really only one way to install them. But I suppose they could be backwards in regard to the direction the rotor turns. (Directional)?

Anyone care to shed some light?

 

[rswyan]

If the pads are identical to each other and are symmetrical in shape, I'd think that that no, they can't be installed "backwards ... except to the extent that you install them with the backing plate against the rotor and the friction material against the caliper piston ...

 

[LD1]

Well my reason for asking....

I but brakes on 20k miles ago or so.

Always do my own. And several friends and relatives. Probably average 5-6 brake jobs a year.

Well the wife's car needed new tires. Can get the tires I want (MasterCraft set touring) locally for $100 a tire.

Well, about 7 years ago (a few tire changes ago), I had a less than stellar shop change the tires. And the idiot behind the machine whacked one of the tpms sensors with the spoon and hasn't worked since.

New sensor at dealer is $70. And they were $5 per tire more out the door for the same tire.

So I decided to let them do it and address the sensor.

Well it turns out they said all 4 sensors we're bad so forget that, just do the tires. I wasn't there, my wife took it in.

They told her that " the front brake pads are on upside down. Do you want us to fix that"

Obviously she said no and called me. I told her to have them note that on the invoice so "her husband would know what to fix".

Sure enough. Front pads upside-down noted on invoice.

So I suspect they we're just trying to take advantage of a female in the dealership with a load of BS. So before I call them Monday and five them a piece of my mind, I wanted to ask the above question.

Bad part is we bought this Sentra new in 2008at this dealer. And are going to buy another new car next year and the wife really likes the altimas. Guess where we aren't buying from

 

[Rustyiron]

That sure sounds like BS to me, but I understand your concern about a slap down (being wrong), :laughing: but if identical, how could it be?

 

[rswyan]

I'd wanna see the shape of the pad ... but hard to imagine they could be "upside down" ...

 

[oosik]

Hmmmm..... I've replaced the front disk pads on my Jeep vehicles a few times and never had a problem. Its probably because there is only one way to install replacements. Believe me - if there were more than one way, I'm likely to be the one to try it backwards.

 

[LD1]

All 4 pads come in the same box.

Everything I have done have had 4 identical pads with the exception that sometimes only two have the squeaker. And I make sure each side gets one.

So yea, I am kinda second guessing everything because I want to make sure.

And didnt know if their was a certain direction they were "supposed" to go, like if you look at a replacement belt for a belt sander....there is always a directional arrow??

 

[rswyan]

In my experience they should not be directional in terms of rotation.

The only exception to that that I can think of might be some kind of aftermarket high performance application.

I don't actually know of one, but that's the only thing I can come up with as a possibility ... and even that seems dubious to me.

 

[TMGT]

Typically the wear indicators (squeaker) have a position they are intended to be in, it is possible to put the pads on the wrong side and have the indicator say, on the trailing edge as apposed to the leading edge. This could be referred to as the pad being "upside down" as that is how it would appear. And no they don't have directional indicators except in very rare and specific applications.

I haven't done brakes on a Sentra in awhile but I can ask my Nissan tech friend about the specifics for your car (15 year Nissan master tech) if you'd like.

 

[pmsmechanic]

If the pads were to be installed in a certain position I'm sure there would be all kinds of markings on the pads and specific installation instructions with the new brakes. If you want to double check get onto a Sentra forum and ask questions. I'm sure someone there will know for sure. Or see if someone can check into a service manual for the correct procedure.

I often run into this at the VW dealer where my wife gets oil changes done. The Napa air filter needs changing because it doesn't fit quite right etc. She's smart enough now to say leave it for next time or that my husband will do that.

I always install the squealer on the outside of the rotor. For one thing that's the only place I've ever seen them and secondly it's the outside pad that generally wears the most.