[Cane Prevost]

Been trying to fix a passenger side rear wheel squeak for a while. First thing I thought was that maybe the brakes were bad. Pulled the drum off and they looked fine. Parts were cheap so I ordered brakes and drums and went ahead and replaced the parts. Still squeaking. Strange because sometimes it would get worse and sometimes not too bad. Jacked car up and looked at rear axle/shocks etc. Nothing looked funny. Pushed and pulled on the wheel to see if it was wheel bearing. Seemed OK. Decided that maybe it was the bearing going out. Ordered the part. Only 40 bucks so what the heck. Put the new bearing on today. Was quite a job. I’m handy but not a mechanic by any means. Was proud to get the bearing replaced without messing anything up. Put the car together and go for a ride and it sounds exactly the same. Squeak coming from right rear. Park the car in the driveway and walk around to the back. Lean on the car and it moves just a bit. I hear the squeak. Push the car again and there it is. You guessed it. The damn front wheel. Crazy how it sounded like the rear wheel. Even had the tire shop drive it around and they said the same thing.
Anyway, jacked up the front and spun the wheel and it’s definitely squeaky. Did the same with the driver side. No squeaks. The brakes have plenty of wear left so it’s not worn brakes. Both wheels spin the same so it’s not a stuck caliper. Wondering if at this point I should just replace the shoes and disks up front? The squeak is really loud and audible when I jack up the car and spin the wheel. Anything you would try before throwing more money at it?

 

[sokoloff]

Throwing parts at the car can get very expensive very quickly. I sure can't tell you what the issue is, but I'd sure do some serious investigation. If it was mine and the brakes looked good and were within spec, I'd sure not replace them. Not much help from me, but I do wish you good hunting and good luck.

Len

 

[Cane Prevost]

Yep. I’m at the tire place. Decided I’d let them look it over before throwing more money at it. I’ll report back when I know. Thanks.

 

[vadsoom]

Check the thrust bearings at the top of the shock towers. Pm sent

 

[Cane Prevost]

Tire guys say everything is fine. Noise is coming from brakes but everything operating properly. Going to ride with it for a while and if it continues or gets worse I guess I’ll replace the pads.

 

[vadsoom]

Good deal. Check for a lip of material around the rim of the brake rotors (inboard and outboard). If you find one, it can be sanded off.

Most of the brake rotors I’ve bought for the smarts can rust over night. I actually had a set that rusted so badly while I was in Europe for 6 weeks that the pads became detached from the backing and had to be replaced. My smart is garaged and I don’t drive it much (it’s my fun car!) so when I drive it, I give it a little push by hand to make sure the brakes are free before I let the engine torque the rotors. After a few minutes of driving, the grinding noise from the rust should go away.

There is another possibility - the smart has springs that are supposed to hold the brake pads away from the rotors when the brakes are not being applied. If these springs are not flexing properly, or the caliper slides are binding up, the pads can contact the rotors and make a squeak, but if this was the case, applying the brakes would stop the noise. Check and grease those caliper slides every time you have the brakes apart.

If it’s really bad, there is a kind of glue that can be put on the back plates of the brake pads that help the pads to be pulled away from the rotors to prevent noise. It’s “anti squeal compound” and it’s available at almost any auto parts store.

 

[sokoloff]

Are the brakes/rotors original? Mercedes makes an anti-squeal brake paste that I use whenever I do anything on the brakes. That's probably what Vadsoom is referring to.

Len

 

[Cane Prevost]

Brakes may be original. Car only has 19K miles on it. Brakes were squeaking when turning the tire by hand when I had the front lifted so it wasn’t vibration caused. Figured the brake grease wouldn’t help with that?

 

[sokoloff]

If they are squeaking when turning by hand, then it sounds like there is something between the rotor and the pad(s). The pads typically have a "noisy squeaker" piece of metal that will give you a warning when the pads are at or below minimum. That doesn't sound like your problem, since you say the pads look good. Maybe a pad(s) has started to come loose from the backing and are constantly rubbing the rotor? All guesses here of course. I'd hate to throw new brake pads/rotors at it until you know for sure, but if you get to the point that you have to take everything apart, it almost makes sense to just replace the parts with new.

Len

 

[smark]

Tire guys say everything is fine. Noise is coming from brakes but everything operating properly. Going to ride with it for a while and if it continues or gets worse I guess I’ll replace the pads.

Replace your OEM brake pads, with ceramic ones. Very little, to no Nasty brake dust. No squeal.

 

[Shalmaneser64]

Brakes may be original. Car only has 19K miles on it. Brakes were squeaking when turning the tire by hand when I had the front lifted so it wasn’t vibration caused. Figured the brake grease wouldn’t help with that?

Your car is 8 years old. If the brakes are original, they're 8 years old too, regardless of miles. Discs and pads are cheap and easy to replace. I put a set of slotted and drilled discs with pads on for under $70.

 

[Cane Prevost]

If the noise doesn’t go away in a couple of weeks I think I’ll switch to ceramic pads and go ahead and change out the rotors as well. Looks like I can do it for around 50 bucks all in. That’s pretty cheap.

 

[Bob Ricewasser]

I replaced the original pads on both our 08 & 09 451's with ceramic pads that I acquired from O'Reilly Auto Parts. They are quiet and the dust deposits on the wheel rims is much, much less.

 

[Cane Prevost]

If they are squeaking when turning by hand, then it sounds like there is something between the rotor and the pad(s). The pads typically have a "noisy squeaker" piece of metal that will give you a warning when the pads are at or below minimum. That doesn't sound like your problem, since you say the pads look good. Maybe a pad(s) has started to come loose from the backing and are constantly rubbing the rotor? All guesses here of course. I'd hate to throw new brake pads/rotors at it until you know for sure, but if you get to the point that you have to take everything apart, it almost makes sense to just replace the parts with new.

Len

That was my thought as well. I’ll take it apart and look for anything wrong with the pads before ordering new ones. They have plenty of wear left.

 

[Shalmaneser64]

That was my thought as well. I’ll take it apart and look for anything wrong with the pads before ordering new ones. They have plenty of wear left.

Rotors are cheap. if they are originals, replace.

 

[sokoloff]

Watch how you go "cheap." There is a lot of cheap Chinese junk out there. Personally I never replace rotors unless they are below minimum specs or if they are warped. And I never resurface rotors.

Len

 

[smark]

I replace both my ceramic pads and rotors, at the same time. Didn’t cheap out. I had EBC green Pads and the OEM rotors on the car before. The EBC had some kind of break in compound on them. They cleaned up the rotors, Scratches and score marks. The EBC were great braking pads. Just really dirty ones. Filthy pads.

 

[vadsoom]

Have a good look at the inboard pads. In many cases, inspection of the outboard pads looks ok, but the inboard pad has been worn down to the “telltale squeaker” that is designed to rub against the rotors letting you know it’s time to replace the pads.

The inner and outer pads will often become unevenly worn if the caliper slides are gummed up, causing the caliper piston to press more on the inner pad than the outer.

This happens because the caliper is designed to “float.”
When the brake pedal is pressed, the caliper extends a few fractions of an inch until and any the floating bracket apples even pressure to both inboard and outboard pads simultaneously. If the caliper bracket is binding, caliper bracket won’t be able to apply even pressure on both the the inner and outer pads simultaneously, and the inner pad will take the brunt of the caliper’s force, causing uneven wear on the inner pad and internal rotor surface.

The moral of the story... every time the wheels are removed, make sure those caliper slides are greased and moving freely and you will save a ton of money and aggravation.

 

[Shalmaneser64]

I replace both my ceramic pads and rotors, at the same time. Didn’t cheap out. I had EBC green Pads and the OEM rotors on the car before. The EBC had some kind of break in compound on them. They cleaned up the rotors, Scratches and score marks. The EBC were great braking pads. Just really dirty ones. Filthy pads.

I agree. Replace everything. Quality rotors are inexpensive, all things considered. Sadly, even the better stuff seems to be made in China today, but I think that there is some degree of quality control. Certainly better than it was years ago. Go with a brand name and you should be fine.

 

[Cane Prevost]

Got it fixed! Rotors and brake pads did the trick. Strange since the pads were in great shape and had plenty of wear left. Changed them out and put in new rotors and the noise is gone. Feels pretty damn good to have solved it. Even with all the extra parts I’m still under 150 bucks total and now I know how to do a complete brake job on a Smart.