Technical Snapped a bolt on the rear caliper

[d0mokun]

Hello again everyone,

In the process of renewing the A500 I've snapped one of the rear caliper bolts. It had the strength of chocolate, something I didn't find until I was doing the thing back up.

The bolt in question is the one in the photo I've attached (I borrowed the photo from the net). There are two on each rear caliper and they appear to attach the carrier to the caliper.

Where can I get these bolts? I want to renew them all. The dealership tells me they can't order the bolts by themselves and instead I'd need to order OEM pads at £stupid per side.. pointless when I've fitted Brembo stuff for a fraction of the cost.

Thanks again
Dan.

 

[Davren]

Hello again everyone,

In the process of renewing the A500 I've snapped one of the rear caliper bolts. It had the strength of chocolate, something I didn't find until I was doing the thing back up.

So, it was stronger than chocolate when you undid it, but didn't have the strength of chocolate when you did it back up.

It's probably the same size bolt on several similar size Fiats. Take a non-chocolate one to any breakers yard. They should be able to match it.
.

 

[d0mokun]

Haha, this is true. I don't particularly trust brake related bolts a second time around, but nowhere suggested these ones might not make it through being torqued.

A breakers yard is a valid one, thanks for that. The only thing I'd be worried about is that the bolts had been weakened previously, something I don't guess is expected with a new bolt.

Dan.

 

[John202020]

Measure the bolt and look on EBay stainless ? Noting they're probably metric fine 1.25 pitch? Why not also buy some stainless screws for the front and rear inner wing guards mine were really hard to remove once totally rusted.
How about a torque wrench too?

 

[d0mokun]

Measure the bolt and look on EBay stainless ? Noting they're probably metric fine 1.25 pitch? Why not also buy some stainless screws for the front and rear inner wing guards mine were really hard to remove once totally rusted.
How about a torque wrench too?

That was the problem, I did use a torque wrench set to the correct settings. The bolt had other thoughts on its tolerance rating, clearly.

Thanks for that idea though, will have a look with those parameters.

Exterior trim screws I've already bought a bag of, for a fair few of them were AWOL or chewed up too!

Dan.

 

[John202020]

Can you get the snapped off piece out easily?

 

[Ralf S.]

Can you get the snapped off piece out easily?

The bolt sits with an open end in the carrier which is where they get wet/corroded...then the thread becomes very difficult to remove, since it's a fine pitch (so no room for the bolt thread to cope with any dirt/distortion/corrosion).

But at least when they snap off, you can drill them out, since the wrecked thread can screw "out" of the hole by passing through the hole and dropping out the other side, just if you give it some regular clockwise drilling.

Easiest source for these bolts is fleabay.

They're very likely M12 x 1.25 (fine pitch) c.35mm (but measure yours... they mustn't be too long since they pass through the carrier and would catch on the disc).

When you fit them, clean out and de-grease the carrier hole first and stick some instant gasket in the end of the carrier hole, where the bolt thread will appear. This will help it seal out any water/salt ingress so the bolt stays dry and the threads at that end uncorroded.

Then grease up the whole bolt to buggeration, including the head, so that it has more protection.

The bolt has to be high tensile (I think they're marked 10.8 but they may be 12.9).. but if you buy fine-pitch they're likely to be that grade anyway. Don't use stainless steel.. apart from it's virtually impossible to find fine-pitch stainless (because fine-pitch usually suggests high tensile) .. it's nominally not strong enough for this job.


Ralf S.

 

[typecastboy]

Shame I got rid of my breaker last week. I could have sorted you out. Try Club500Italia on eBay they are very good?

 

[d0mokun]

Thanks for the notes and help, guys. I must have missed the post notifications.

In the end I managed to get the bolts from.. you guessed it.. a Fiat dealership! It's amazing how one dealership will tell you a totally different answer to another one.

Bolt wise, the snapped one came out quite easily because it snapped with just enough metal proud of the hole. Meant I could work it out with some good grips, slowly but surely.

Dan.