Why did these pop rivets fail?

[Rudi McAnichal]

Dust shields for rear brake disks of the Panda 4x4 have both come adrift in the past fortnight (4 year old car, 43k miles). No fasteners remaining, but judging from this diagram it looks as though the shields must have been held on with pop rivets. https://www.fiatdalys.lt/en/catalog/...0/0/brake-pads
Rivet holes in the shields show no obvious signs of damage or corrosion.

What is the most likely cause? Insufficient tension in the pop rivets, allowing the shields to “chatter”? Galvanic corrosion where pop rivets meet the steel shield? Or something completely different?

Car will probably have to run without those dust shields from now on, as they are not easily replaced. It would have been a five minute job to remove the disk and re-fit the shield on the previous model, but it seems that rear disks on post-2012 models cannot be removed without dismantling the hubs, and it is almost impossible to do this without wrecking the bearings. Unless you know different?

 

[slim_boy_fat]

It's a Fiat.............

Can you not re-rivet from the other side, or is there insufficient clearance?

 

[brightspark]

corrosion on the rivet . salt the rivets aluminium with the steel pull inside . the head of rivet has corroded off

 

[Pete.]

Could be the original rivets were steel but the replacements were ally. I found a small number of steel ones on site once. They were hard to pull but very strong compared to ally ones.

 

[Ton-up]

Surprised you haven't got the pop rivets left and no Fiat!

 

[gordon stephenson]

X2 on the corrosion theory. Rivets of incorrect material

 

[Paul.]

Put some monel pop rivets in, should stop it happening again

 

[Rudi McAnichal]

It's a Fiat.............

Fiats - they don’t make them like they used to. In fact, they hardly suffer at all from tin-worm nowadays. Polish-built Pandas (2004-2012) were generally very well built, which might come as a surprise if you are old enough to remember Polski-Fiats imports of the 1960s. This 2013 Naples-built Panda has also been very good, until the dust shields came adrift. Hope the MOT inspector does not complain about their absence, but that is not due until next January.

Can you not re-rivet from the other side, or is there insufficient clearance?

Not a chance. Do they design cars this way just to cut manufacturing costs, or is there a deliberate intention to make them non-repairable?

 

[Migmac]

The ones on our Zafira rotted off, been through two MOTs without them

 

[Rudi McAnichal]

Many thanks, folks, good to hear that MOT may not be a problem. Car looked a bit odd when the shield on just one side had come adrift, better now that both have gone.

Dust shields rotting away in Angus and Kintyre, comments about corrosion from Teesside and Cleveland, and my car lives in somewhere in between (Peeblesshire). Probably related to road salt levels in the North.

Nothing left of any of the rivets, so I’ve no idea what they were made of, but a steel/aluminium junction would certainly not seem very clever on the underside of a car. Several college pals got vehicles through the MOT with pop-rivetted sills, but that was 50 years ago, when inspectors were more lenient.

 

[Cobbler]

Pop riveted sills, standard practice on Mini's in the late 60's. It allowed you to change them every year for the mot!

"Change the oil, filter & sills please" ......... joking really, but nearly that bad.

 

[Migmac]

Many thanks, folks, good to hear that MOT may not be a problem. Car looked a bit odd when the shield on just one side had come adrift, better now that both have gone.

Dust shields rotting away in Angus and Kintyre, comments about corrosion from Teesside and Cleveland, and my car lives in somewhere in between (Peeblesshire). Probably related to road salt levels in the North.

Nothing left of any of the rivets, so I’ve no idea what they were made of, but a steel/aluminium junction would certainly not seem very clever on the underside of a car. Several college pals got vehicles through the MOT with pop-rivetted sills, but that was 50 years ago, when inspectors were more lenient.

Purely sea salt here, lovely area to live in but everything metal rusts quickly

 

[pedrobedro]

Work mate of mine had a FSO Polonez and it never let him down mechanically but it was a pile of rust and the ugliest thing I ever saw on the road. The shields on discs are an optional extra aren't they ? On my sister's Metro they were a pain as they always trapped pebbles and sounded horrible.

 

[Bigjoe]

Ooh peebleshire I used to live there! How is the old place? Keep meaning to go back but not made it yet...I remember getting the hump with an mot tester who failed a Honda civic with a rotted away dust sheild

 

[Rudi McAnichal]

Ooh peebleshire I used to live there! How is the old place?

Peebles town is expanding rapidly, with new housing estates in every direction. Lots of large new dwellings, presumably to accommodate large families. Looks as though people are going to Peebles to live, whereas in previous decades it was said that they went to Peebles to die.

 

[Migmac]

I was brought up in Peebles, small world

 

[slim_boy_fat]

My nephew lives out at Lamancha, just down the road.

 

[Bigjoe]

I lived in Innerleithen for 7 years, very small world