Vehicle brake question

Factual Questions
1

I’ve a 2004 Ram 1500 4x4 that I use pretty much exclusively for plowing snow. I plowed yesterday. Very deep snow, 24 inches. The brakes grunt and groan a little bit, I think because they are getting so, so wet from the snow. But they work.

Today, I had to plow again. The brakes simply would not stop the truck. It would roll with the brakes on at idle if I put it in drive or reverse. Lots of grunting and groaning from the brakes. I don’t know how else to describe the noise. Brake fluid level good. Four wheel disk brakes, and I really am not sure how good the pads are. The Truck is kinda new to me. Just over 100,000 miles. Definitely time to look at them this summer.

Thinking that they may be very, very wet from when I parked it yesterday, I slowly moved the truck back and forth with the brakes on. The hope was to heat them up and dry them off. It worked, or did something…

This doesn’t really make sense to me though. The plowing yesterday should have heated the brakes up to the point that no moisture would collect on them. And in any case, I didn’t think that wet brakes where really an issue anymore.

Could it just be wet brakes?

2

How about iced brakes? If they were wet enough, and then conditions cold enough, you could have ice buildup on the rotors or under the pads that would have to scrub off or melt/evaporate away before you got full brake authority back.

3

Maybe iced brakes. They certainly got wet enough, and it was certainly cold enough. I’m lucky that I was just plowing my own driveway when this occurred.

4

I don’t have any experience plowing in feet deep snow but your description of “grunting and groaning” brakes sounds pretty much exactly what brake pads that have completely worn down and are grinding into the rotors would sound like. If that’s the case, you will have unfathomably terrible braking performance for a little while until you have absolutely no brakes at all. Pull the wheels off and check the pads and rotors. If I’m right, you probably have deep gouges in the rotor surface.

5

Yeah, but they work fine when dry and warm. Don’t most pads have a ‘squeal’ tab on them that will, well squeal when your pads get dangerously low? My '76 Chevy had those (on the front, rear drums)

6

Well, working well when they are dry and warm is a good sign. Not all cars have the little squeal tab on them. I don’t know about your truck but my 2006 sedan lacked them. The service requirement was to inspect them every 10,000 (I think) miles.

Looking online, I see that your owner’s manual says, “Repeated or continuous noises during braking may be an indication that the brake linings are worn and in need of replacement.” It doesn’t specifically mention squealing as the noise. Service Schedule B for your truck (including plowing) says to inspect the brake linings every 12,000 miles. Checking one picture on line of brake pads for your truck, I see the brake shims included with the set but not a separate brake squealing tab. Even if it’s supposed to be there, are you sure that the last monkey who changed the brake pads installed it correctly?

7

My car didn’t squeal at all. I’ve just replaced the rotors all round: The front ones were deeply gouged, and the rear ones too thin to machine. Just a kind of noise like the tires were rubbing when I slowed down to turn a corner.

8

Thanks all. I’ve only put a few thousand miles on this Truck that has 100,000 miles on it. Who knows what happened before. I think I put it through a mechanics checkup when I bought new tires for it a few years ago. But… don’t know. I suspect it does need brakes, but I can’t do anything about that until summer which is a few months away. March and April are our heaviest snow months, and it doesn’t all melt until June.

9

No this is not how it works, unless you actually pop out the cylinder and lose the brake fluid seal. More then likely it will bind up, locking a wheel as the pad backing becomes loose and tried to slip under the bracket or the rotor wears to the veins and is bound up by them.

10

The last few rotors I’ve taken in to be machined were too thin. Do shops even do that anymore?

11

Had a vehicle one time where the pads broke off and never let me know.

12

My mechanic is in an industrial estate with a lot of crash repair, engine modification and similar near by. There’s somebody just up the road that’s a brake specialist and shaves rotors.

13

When you buy rotors, you may be offered a choice between expensive and much cheaper ones. Choose the cheaper ones, and then no, it won’t be possible to machine them, but choose the expensive ones, AND do not ignore advice from mechanics who check your pads periodically and tell you when you should check again, and how soon you should expect to need brakes, and you will be able to have them machined.

BTW: another possibility on the truck in the OP is a seized caliper. Usually, they grip too hard, because they seize closed, but they can seize open, and groan when you try to apply them, and not close well, so they don’t work well-- and actually, I’m saying “them,” but it’s probably just one. If you were noticing problems at low speed, it’s likely a front one.

Everything on a vehicle loosens up as it warms up, so a caliper in the process of seizing may free up a little as it warms up, but it still needs to be replaced. Driving around will a stuck caliper is a good way to blow a wheel cylinder. Then you have a very expensive repair.

Vehicles that are driven only occasionally are good candidates for seized calipers, although I don’t know the reason. I just know that when I worked in a shop, and a car came in for it “I hardly ever use it” was something people said a lot on hearing that a vehicle had a seized caliper. We were also told to watch for them on military vehicles in the motor pool at my guard unit, since so many of the vehicles didn’t get driven much. In fact, a lot of my drill time was spent cruising around in Humvees, light trucks, and cattle trucks, to make sure they were running well, keep the parts greased, etc.

14

Interesting RivkahC. Didn’t think about a seized caliper. Could be a number of things I suppose. I’ll check it out this summer. The truck rarely leaves our property and is never on pavement/public roads in the winter time.

15

Rotors came with the car. Took them to several places, all of whom said they didn’t turn rotors anymore. Finally found one guy who said he would do it, but they were borderline and advised me to buy new rotors. He claimed they are made on the thin side now, and are not worth turning.

Gave up and replaced them.

16

I’ve heard that auto manufacturers do whatever they can to reduce weight to meet fuel efficiency requirements. One way to do that is to use thinner brake rotors that can’t be turned and have to be replaced.

17

good point 74westy.

Plowing again today. Brakes on truck seem ok. truck is warming up now. I’ll know if I can plow in a few. But certainly something wrong with brakes.

18

Well, that’s how they make them cheaper.

The major factor in rotors becoming single-use was that the price of pads continued to rise as the materials they were permitted to be made from became more and more restricted, and so people put off replacing them longer and longer, until it wasn’t a choice anymore, and by then the rotors were damaged. Rotors were getting turned far less often, so the machines to resurface them were sitting idle. If they broke down, or needed replacing for obsolescence, they simply didn’t get replaced, and shops started saying they didn’t turn rotors.

The market for cheap, which is to say, thinner rotors, that lasted through only one set of pads, became standard.

There’s a lesser factor that has to do with the free-standing tire places trying to cram as many 4-tire replacement appointments into an hour as they could, and looking the other way when mechanics used impact wrenches to put wheels back on cars, instead of torque wrenches (customers watching usually don’t know better). The result of that was that lug nuts were too tight, rotors got warped, wore out faster, AND couldn’t be turned.

Cheap rotors that can’t be turned don’t cost half what better rotors cost, though-- anywhere from 65-85%. But if you invest in the good ones, you have to replace your brakes when it’s recommended, and when you get tires, tell the manager to make sure the mechanic uses a torque wrench to replace the wheels. Just the fact that you know to say that will put them on notice. Although, the only way to make absolute sure your rotors don’t get warped, is to invest in a torque wrench (one good enough for home use is $25), and then every time a shop removes one of your wheels, as soon as you get home, loosen the nuts, and use the torque wrench to put them back on to spec.

I do.

I worked in a shop for a couple of years, and there are a few take-aways I live by, That’s one.