Technical Fiat 500 Brake drum removal

[Tropicalmike]

I was servicing my daughters newly purchased 2016 Fiat 500 lounge. It only has 33000 on the clock but I thought I would check the back drum brakes as there was no service record to suggest they had ever been looked at let alone brake shoes replaced. But I couldn't get the drums off with the usual penetrating oil, screw driver leverage and a bit of hammer action that has been sufficient on other drums I have removed before. The hubs didn't look particularly rusty . Then I noticed that the holes for the 2 drum securing bolts / wheel locator pin in the drum were also threaded that looks like extractor bolts could be used . The size being a bit larger that the drum securing bolts thread , But I didn't have any suitably sized bolts in my odds and sods and neither did my neighbour in his! Any one ever used these extractor threads before ? It looks like M8 but I am not sure so just want to know the size please ???? I tried looking at the E-learn website but it didn't give details in the R-R part, just said remove the drum.

Or anyone got any other clever hacks for freeing up a drum off the hub . I was a bit pushed for time today otherwise I might have tried giving it a blast with my blow torch

Thanks in advance

 

[PuntoHowTo]

With a flat screw driver, poke it though the wheel bolt holes to the self adjuster and wind it back.

Usually there is no need to be bashing things with a hammer.

 

[varesecrazy]

I was servicing my daughters newly purchased 2016 Fiat 500 lounge. It only has 33000 on the clock but I thought I would check the back drum brakes as there was no service record to suggest they had ever been looked at let alone brake shoes replaced. But I couldn't get the drums off with the usual penetrating oil, screw driver leverage and a bit of hammer action that has been sufficient on other drums I have removed before. The hubs didn't look particularly rusty . Then I noticed that the holes for the 2 drum securing bolts / wheel locator pin in the drum were also threaded that looks like extractor bolts could be used . The size being a bit larger that the drum securing bolts thread , But I didn't have any suitably sized bolts in my odds and sods and neither did my neighbour in his! Any one ever used these extractor threads before ? It looks like M8 but I am not sure so just want to know the size please ???? I tried looking at the E-learn website but it didn't give details in the R-R part, just said remove the drum.

Or anyone got any other clever hacks for freeing up a drum off the hub . I was a bit pushed for time today otherwise I might have tried giving it a blast with my blow torch

Thanks in advance

Yes - it's a finer pitch though

And rusty threads convince you it's the wrong bolt.


Be warned, you may find the drum has worn a groove, and using bolts will risk shearing the pin-clips that secure the brake shoes


It's possible to apply pressure with the extractor bolts AND rotate the hub..

Twisting the Drum over the Shoes

EDIT - the parallel tube of the hub is actually a snug fit on the drums mounting bore.. So a wire brush and emery could prove useful

I seldom have success with the self-adjusters.. Seen 6 or so designs over the years, most are problematic

 

[Tropicalmike]

Thanks guys for the prompt replies

So is it an 8mm thread ? but a finer pitch than a standard M8 x1.25 pitch . Looks like 1.0 pitch also readily available . do you think that is it ? Probably difficult to remember I guess unless you have the said extractor bolts in your toolbox/workshop. TBH it looked to be more coarse that the 6 mm thread in the hub.

With a flat screw driver, poke it though the wheel bolt holes to the self adjuster and wind it back.

Usually there is no need to be bashing things with a hammer.

The drum centre is seized on the hub , It is not an issue with the brake shoes as far as I can tell , the pedal and the hand brake work ok and the drum turns freely with out any binding so need need to touch the self adjuster at this stage. Just need to crack the seizure off then carefully wiggle the drum off over the shoes. I have already wire brushed the hub so the drum will pass easily over the hub.

Thanks

 

[varesecrazy]

From memory it's M10 x 1.25
So Metric Fine

Not the standard M10 x 1.5 = Metric Coarse

Mine are old wheel bolts, with a fine M10 thread cut on them instead of the standard M12

Very handy as I use the same wheel brace to drive the hub off

 

[John202020]

If you get the drums off, replace them they're cheap enough or grind off the lip on the inside edge

 

[Ralf S.]

The Younger Mrs S' Cinquecento traumatised me for drums.. I haven't touched her 500 yet, but I can't run forever..

I found it was easier to remove the drum after undoing the brake bleed nipple on the back.. that allowed the shoes to press in the slave cylinder enough to escape the groove they had worn for themselves, so that the drum could be removed.

I can't remember Cinquecento had anything too sophisticated like a windable self adjuster in it.. but hopefully 500 might have a gadget that makes it easier.


Ralf S.

 

[steveras57]

The Younger Mrs S' Cinquecento traumatised me for drums.. I haven't touched her 500 yet, but I can't run forever..

I found it was easier to remove the drum after undoing the brake bleed nipple on the back.. that allowed the shoes to press in the slave cylinder enough to escape the groove they had worn for themselves, so that the drum could be removed.

I can't remember Cinquecento had anything too sophisticated like a windable self adjuster in it.. but hopefully 500 might have a gadget that makes it easier.


Ralf S.

You think Fiat might make it EASIER!

 

[rmjbn1]

Mine had a rusty lip on the inside of the drums.

Combination of hammering, prying and turning got the drums off.

Had to drag the drums over the shoes though.

I like the idea of undoing the bleed nipple, maybe backing off the adjusters if you can manage, to try and avoid damaging the shoe linings.

Then either grind off the rusty lip or replace.

 

[John202020]

I found it was easier to remove the drum after undoing the brake bleed nipple on the back.. that allowed the shoes to press in the slave cylinder enough to escape the groove

It's the auto adjusters that keep the shoes out if they're still working, the bleed nipple usually seized ?

 

[Tropicalmike]

I have ordered some M10 fine thread bolts to use for extraction. I can check it is the correct size on my wife's 500 before my daughter next visits. I found out that the two drum securing bolts/wheel locator pins are listed as M8 via the e-per so the the extraction threads must surely be 10mm.

I've noted the tips about opening the bleed nipple and the adjuster . TBH the two sets of drums I have opened before on 500s only had <35k miles on them and the lip was miniscule and the shoes had plenty of meat left on them. I guess it depends on on how hard you brake but I think shoes and drums can last to 50k miles without issue. So I am hoping that at 33k it will just be a brush clean and blow out and stick the drums back on .

I'll keep you posted.