Does this sound like a wheel bearing, disc or seized caliper?

[PJayUK]

My W210 has developed a slight rumbling noise that is only noticeable at slow speeds (around 5 - 15mph). Its accompanied by some slight vibration that can be felt through the brake pedal but its not related to brake use, in other words it can be felt if I rest my foot on the pedal (without pressing it) at slow speeds.

I had the front wheels off last night and noticed that the offside one feels like its binding a bit when I span the disc. It certainly didn't rotate smoothly through one complete revolution. There is no discernible play laterally which made me think that perhaps its not a wheel bearing but a damaged disc or seized caliper.

The car is driving fine (apart from the slight issue mentioned above) brakes are efficient and stops in a straight line there is no wheel wobble but the drivers side wheel is slightly warmer to the touch after a run.

Not sure what the best course of action is really but I was thinking that re-greasing the bearings might help or perhaps replacing the discs.

Before I dive in or call a friendly indi has anyone got any offer any pointers, tips or views on what this might be and what I should do next?

As it happens, is there a howto that covers how to grease and adjust wheel bearings?

 

[kwakdonut]

I would say that it sounds like a partially seized calliper or warped brake disc.

I would remove brake pads and check the calliper and also do a visual on the disc.

 

[MOR8A]

Sounds like a binding caliper to me. Try to have a drive without using the brakes much or hard. Then feel the wheels and brake discs (cafeful though of the discs) if one is hotter than the other its a binding caliper. It maybe that if you remove the caliper and are able to push the pistons back in with a large pair of swannecks that you could free it off. If not its either a caliper overhaul or a new/replacement caliper. If you are not able to understand my crap explanation come back to me, I could talk you through on the phone. Hope this helps?

 

[PJayUK]

That makes sense, I'll try and drive the car and avoid braking to see if the wheels/discs re warmer on that side. Just a thought though if the caliper was binding wouldn't I feel roughness and binding throughout the entire revolution of the disc/hub etc?

It only seems to bind part of the way round....

(I hope its not the caliper I need to drive the car to Northampton tomorrow for work!)

 

[MOR8A]

If the caliper has been over heating the disc for a while now it could have warped the discs a little, plus are the discs in good nick or a bit passed it?

I would still wip off the calipers from their mounting (leave the hose connected) and see if you can move the piston(s) in and out and round and round. Take care when pushing in the pistons as this will refill the bake fluid reservoir. You do not want this to spill out all over the inner wing paint or whatever, keep your eye on it. If you think it is going to spill out you can either use a syringe to suck some out or failing that a bit of kitchen roll (mind that paintwork though) is you spill some on the paintwork was off with lots of water.

Good luck.

 

[PJayUK]

The discs are not in bad nick, there not badly scored but they do have a slight lip on them.

I'll have a go at freeing the piston can these be lubricated?

 

[MOR8A]

You can put some wd40 on the pistons in the hope that the capilary action my slip down the side to free the corrosion, but keep it away from the discs and pads.

 

[BlackC55]

If there is no wheel bearing play it sounds like you have a warped disc. The calipers on 210's are generally very good and don't often seize.

Check the pads are free in the carrier too and re-grease them.

 

[arkamelis]

hi pjay, let us know the outcome when you work it out, good to know if it happens to mine at some point.

 

[ringway]

The single piston calipers are £106 each from MB dealers although they are obviously available for less if you shop around.

 

[PJayUK]

If there is no wheel bearing play it sounds like you have a warped disc. The calipers on 210's are generally very good and don't often seize.

Check the pads are free in the carrier too and re-grease them.

Will check the pads and regrease them as well.

Just another question, theres a place near me that does brake disc skimming on the car using a lathe.

Has anyone had any experiences of these types of service before?

Is it worth doing even as a stop gap?

 

[iscaboy]

Just another question, theres a place near me that does brake disc skimming on the car using a lathe.

Depends on the disk / wear.

If done by an EXPERIENCED turner then no problems at all.

If done by an IN-experienced turner (e.g. CNC jockey) then you may be lucky, or your disk may shatter / explode under braking.

Frankly, unless your vehicle is seriously exotic new disks cost less than skimming old ones.

 

[BlackC55]

Don't bother with a skim. The discs are cheap enough.