I need rear pads replaced and I'm being told that it's a must to turn rotors when doing this. They say they are always grooved and the new pads won't wear evenly if not turned. Does this hold water? It's new to me. Original pads 65k miles. Thanks
The fronts were turned when replaced by the way about 5k miles ago. Same dealership.

Oh, and don't get the motorcraft generic pads. They were cheap and easy for me, but they dust like a sumbiatch. I want ceramic on the back.

BD

 

You can get away with it, but it's not recommended.

What will happen since the rotor is not flat and the brake pad is, the brake pad will take longer to conform to the rotor. During that period the pad will not be making full contact with the rotor which means less stoping power. Plus the pad will not wear evenly.

So you can get away with it, but it's really not the best thing to do.

 

On the down side of machining the rear rotor would be that you're taking an already thin rotor and making it even thinner, therefore more prone to overheating and more problems (especially if you're towing or something that uses a lot of brakes).

It's your call. I have never been a fan of turning rotors for just the reason stated above. I always either throw new pads in or replace the rotor.

Randy

 

If you want Wagner makes a high quality rotor for $45 each. If you go this (or machined) route ALWAYS wash w/ soap and water before installing, NOT brake cleaner! I recommend machine or replace every time, for the best performance. I also recommend opening bleeders when you push caliper pistons back, allowing brake fluid to exit caliper. This prevents any contaminated fluid from entering the abs system!

Jon

 

It's always been my belief that the rotors need not be cut every time you replace the pads. I do however on 2 occasions. 1, if the pads were let to run down to nothing and the underlying bolts cut into the rotor - like captainoblivious said it's too uneven to brake properly in the beginning and you end up wasting that portion of your pad real quick. 2, if there's noticeable glazing on the rotor - a shiny baked-on film over the rotor surface - it's caused by junk getting between the pad and the rotor and being heated real good when braking, and can also be caused by abuse of the pads themselves (ie: burning out without a line lock kit). The glaze offers too little resistence to the pad, again causing poor braking.

If the rotor appears to be in good condition (no ruts cut into it and no bad glazing), then there's no need to cut them IMO. Especially the rear ones, as they do a small percentage of your braking. In fact, since I change my pads when I hear the warning indicator, I can't remember the last time I had rotors cut, even on the front. Plus like desert said, cutting them all the time wears them down, increasing the chance of warping.

Hope this helps. And FYI, changing your own brakes is a pretty simple process. Good pads only run like $50 a pair - save yourself some cash.

 

why in the world would you wash your freshly machined rotors with water?

and more specifically, why not brake cleaner?

as for the original question.

yes you can get away with just "slapping" some pads on there.

you can also get away with not wiping your butt after you take a dump. (sorry to be crude)

but just because you can do it, doesn't mean that either of the above options is the right way to do things.

yes, machining rotors makes them thinner and thus slightly more prone to warping again. yes, in an ideal situation, you could install new rotors, you'd get a fresh flat surface (hopefully anyway, some rotors come out of the box with runout) and you still retain full rotor thickness.

but since you are asking about skipping the machining process which is USUALLY cheaper than replacing w/ new rotors, I'm assuming you are not interested in purchasing rotors either.

I assume you are on a budget (or just a cheapskate?).

you need to decide just how much of a budget you are on.

is it really worth it to skimp on the maching step? only if you really can't afford it.

another question? did they measure your rotor runout and tell you how much variation you have? this can be done with a simple dial indicator. also, did they measure the rotor thickness?

good luck.

later,
chris

 

Thanks for the replies guys. I know that machining is the best thing to do, but I also knew our rotors couldn't take a lot of it. But, I didn't realize new ones were only 45 bucks.

Superfords- no they didn't measure those things on the fronts when done, or the rears when I was told they needed to be done. I don't fault them for that because I didn't ask. In LA, I doubt they hear those questions very often.

I'll most likely get em turned for the reasons everyone is pointing to. I'm not to worried about the integrity of the rotor until at least the 2nd turning, and I don't road race (although the 605 freeway is damn near worse ).

Also, as for the budget, so I'll have to stay in a night some weekend Mainly just trying to not get the runaround since I'm a little weak on brake knowledge.

BD

 

I'd rather run 24 hours at Lemans than drive the 605 !!!

Seriously, though ...

Teching the brakes is something you should do every month or
so. It's easy ... You can see the pad from outside the wheel
and if it shows 3/8" or less, it's time. Pads cost about 40-90
dollars and are easy to install if you do them all the time.

The only way to learn is to dive in and do it. The fronts at
least need to be turned on the truck, which a lot of brake shops can't
do. I had my stockers turned once, and then they were too
thin to do again. The specs are in the manuals.

The first time I did mine was the first time in 35 years that I
did any mechanical work on a car ... And it felt GREAT to get
all dirty again. Since then I have tackled several jobs that
actually shocked my wife, including changing her brakes and
saving a coupla hundred.

Just do it ....

 

Brake manufacters have recommended washing with soap and water for sometime now, it removes impurities that MAY be left behind or applied on new rotors. Brake clean is great but CAN leave a chemical behind,, these can transfer to your new pads....As I stated above ,, just MY recomendation and it can be done many different ways, this just has worked well for me,,I am **** when it comes to mine and my customers vehicles. I even go out and do a break-in procedure to cut down on noise come-backs.. soap and water is also cheaper than brake cleaner

Jon

 

By all means, if I was still in Kansas where I grew up, I'd do the work because there's nothing better to do. Now, however, time is money. I'm not going to waste it doing the brakes on my truck when I can be on the beach body surfing, playing wiffle ball, chick watching, you name it (yea, life sucks out here). Therefore, I'll pay the SVT dealer to do it while I'm at work (and be sure to have them turn the rotors as well). But, I'll take them the pads I want to use.
It's almost Friday

Thanks all.

BD