Brake Pad & Disc Change W203

[Parrotman]

2003 W203 220 CDI Estate 33K

Got the warning light come on re brake pad wear. Going to replace pads and wear sensors, and also read on another thread to change the self locking bolts also. Is there anything else that ought to be changed as well while I'm at it please?

With respect to disc wear, at what degree of wear should these be changed and how is this best measured please?

Thank you for your advice, John

 

[grober]

You can reuse the locking bolts if you use something like locktite on them. Assuming they are in good nick. If you buy the front pads from Merc they come with the locking bolts. The sensors and high temp grease you have to buy separately and if you are working on fixed caliper brakes like at the rear you have to buy the pins and anti shake clips separately.
Iam assuming you have the floating calipers on the front?

 

[Dieselman]

The disks will have the wear limit stamped on the inner hub. It's probably normal thickness 28mm minimum 25.4mm.

Measure with a micrometer or vernier.

 

[television]

To a certain extent you can measure the lip on the face of the disc if you do not have a micrometer, some micrometers ard difficul to get on owing to the back plate being in the way.

As you said you will have to replace the sensor as you have the two wire type, and a wire will be cut. Do note the hole where it came from on the old pads.

MB say that the piston face should be greased rather than the pads,but I do both.

Its quite normal to have to file the paint off the new pads on the edges so that they slide easily

 

[Parrotman]

You can reuse the locking bolts if you use something like locktite on them. Assuming they are in good nick. If you buy the front pads from Merc they come with the locking bolts. The sensors and high temp grease you have to buy separately and if you are working on fixed caliper brakes like at the rear you have to buy the pins and anti shake clips separately.
Iam assuming you have the floating calipers on the front?

Graeme, thanks for that. Forgive my ignorance but is the ' high temp grease 'the same stuff as the ' copper-slip ' stuff that I've used on previous cars when doing the brakes. If not and to satisfy my interest, what is the difference please?

A further question if I may, would you happen to know what torque the wheels should be tightened to please?

Thanks once again, John

 

[television]

Graeme, thanks for that. Forgive my ignorance but is the ' high temp grease 'the same stuff as the ' copper-slip ' stuff that I've used on previous cars when doing the brakes. If not and to satisfy my interest, what is the difference please?

A further question if I may, would you happen to know what torque the wheels should be tightened to please?

Thanks once again, John

Excuse me answering but it is the copper grease, there are some now that are copper free to avoid possible ABS problems, Its called Cera TEC and it is thinner than the copper one.
I asked Ian Walker what he though of it , but he was unsure at the time. Its a TMD friction product, thats OE to MB

 

[grober]

Sorry just back from the pub. Malcolm has answered your question on the grease. As I recall Merc used to sell it in little sachets. The old stuff used to be blue/green in colour. Something to be aware of is that older cars just had pad wear sensors on the front but later cars using ESR and other traction/stability controls may have wear sensors on the rear brake pads on at least one side also. So make sure the rear pads are OK too. Wheel bolts for older models were normally 81 lbf ft-- 110Nm BUT don't know for certain the value for your W203 model.

 

[television]

Sorry just back from the pub. Malcolm has answered your question on the grease. As I recall Merc used to sell it in little sachets. The old stuff used to be blue/green in colour. Something to be aware of is that older cars just had pad wear sensors on the front but later cars using ESR and other traction/stability controls may have wear sensors on the rear brake pads on at least one side also. So make sure the rear pads are OK too. Wheel bolts for older models were normally 81 lbf ft-- 110Nm BUT don't know for certain the value for your W203 model.

Thanks Graeme on the wheel bolt torque thing, in Sweden they are more fussy than we are, they do them at as you say 100,, and all alloys are the same torque, and they say that they should be reset after one week, or a few hundred miles

 

[FNG08]

In regards to when to replace discs, call me a little prehistoric, but i judge it based on feel.

the last time i replaced them it could fee that it wasn't pulling up as quickly and it was getting a little long in the foot. i check it out (pads looked great) and sure enough the discs were shagged.

i was told by my mechanic that when the outer lip gets to be about 3mm deep then its time to replace.



L

 

[television]

In regards to when to replace discs, call me a little prehistoric, but i judge it based on feel.

the last time i replaced them it could fee that it wasn't pulling up as quickly and it was getting a little long in the foot. i check it out (pads looked great) and sure enough the discs were shagged.

i was told by my mechanic that when the outer lip gets to be about 3mm deep then its time to replace.



L

As per dieselmans post 2½ mm would be spot on for the lip.


Ignore the re tightening thing in my post 8, it is when the temp goes down say to -20c at night, so not for us here

 

[Alps]

i changed my rear discs and pads over the weekend, and had to file away some of the paint on the side of the pads to help them slide easily, remember to get a new disc screw as well, other than that, you shouldnt need anything else.

 

[television]

i changed my rear discs and pads over the weekend, and had to file away some of the paint on the side of the pads to help them slide easily, remember to get a new disc screw as well, other than that, you shouldnt need anything else.

I hope that I am not over posting here, but that scewbit is important, a cheap torx but will shear off in the hole, off the top of my head its a torx 30, using no extension and just the wrench, shock is better than pulling by banging with the palm of your hand

 

[Parrotman]

Thanks for all your help and advice, very much appreciated. Just hope the sun is still there when I do it but knowing my luck it'll probably be peeing down!

Regards John