New caliper bolts?

[Stratman]

I'm looking to renew the brakes on my W203 200CDI. The Haynes manual (yeah, I know) says the caliper bolts are not to be reused and must be renewed as well.

Is this necessary? I've never come across it on any other cars I've owned. If it is are they readily available from the usual places (ECP, GSF)?

 

[Will]

The bolts usually come with a thread locking compound applied to them. Considering all the salt/dirt/moisture etc that they're exposed to it's not a bad idea to renew them.

Shouldn't be more than a quid or two each from MB, or some of the GSF/Euro kits include caliper bolts with he brake pad sets.

Will

 

[johnsco]

I've never replaced caliper bolts on any vehicle I've worked on.
Never came into my head ... Any more than replacing my wheel bolts every time I change a wheel.

Unless someone has over-tightened them and stretched them, I don't really see the need .

BUT.
How would you ever know ?
AND
Does the tightening torque take them close to the elastic limit ?

 

[silver_star]

I have never bothered. The same goes for the bolts that go into the caliper sliders, "oficially" they should also be changed.

I would just wire brush the bolts (provided the thread and head is good) and apply some thread lock compont. That is what I did when I changed my discs.

 

[johnsco]

Again ... I would never change the sliding-caliper bolts.

 

[Stratman]

Thanks one and all.

 

[BlackC55]

If the pads have the new bolts in the box use them.

 

[robotech]

Many thanks for all your help in this matter

 

[optimusprime]

Some of us have no option.When you car is 27 years old ,getting them out can damage them ,so you have to replace them on re fitting . On removal try and use a good spanner not an old one .Or socket if you can get one in there . Spray them with penetrating oil brfore you start.If you find one that wont come free ,pop a bottle jack under the spanner or ratchet to help you undo it.

 

[hotrodder]

As said in this case it's probably because they come with a thread locking compound preapplied. When this is the case some workshop manuals state replace or use a thread locking compound if reusing, at least for less important stuff than brakes. Others just state they shouldn't be reused, presumably to discourage numpties from trying to sue and/or becasue it's easier than trusting in (nearly extinct) common sense to inspect threads and replace any bolts which look manky/suspect

Dunno what size the bolts are on a 203 but it's M12 x 1.5 class 10.9 on my s124 and the torque setting is 115Nm, slightly higher than for the wheel bolts (same size) and between standard 'book' numbers for dry (131Nm) and lubricated (98Nm) i.e. the torque value is relatively conservative (probably due to the female thread?) hence loctiting them rather than relying the elastic properties and torquing close to their yield point [/gross simplification]