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.

 

[Ralf S.]

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

To be fair, on the Younger Mrs S's Cinquecento, the only time the drums needed any attention was when one of the cylinders started leaking.. so the couple of times I did it, I replaced the shoes and fitted a new cylinder (which came with a new bleed nipple) at the same time.

The beast had worn a fair lip on the drum by the second time I did it, so I fitted new drums then too.. and that was the last time I needed to touch it.

Both times, the shoes I replaced seemed almost like new... so I'd say the shoes can almost out-last the drum.


Ralf S.

 

[Pugglt Auld Jock]

Rear shoes do seem to last just about "for ever". When you get the drum off have a very careful look at the bonding between the friction lining and metal shoe, I've seen more than one where the bond was failing.

Probably not impossible to wind back the self adjuster through a bolt hole, but not easy and you risk damaging the mechanism. I like to completely disconnect, or at least wind back, the handbrake cables until they are really slack thus ensuring the shoes are completely returned against the stops. If the drum is seized to the hub, by which I mean not freeing off at all rather than sticking on the shoes, then take a hammer (a 1lb ball pein works for me) and strike the drum on it's face between the holes for the wheel securing bolts - so at right angles to the axis of the axle. So not on the outside of the drum as you'd think normal. The shock usually frees the drum. As soon as it starts to move swop the ball pein for a copper or leather mallet and hit the drum on it's edge which will tend to tilt it and further free it. As long as the drum is still hard against the hub you can nit it really pretty hard without any damage being done but I prefer to hit it moderately hard several times to spare the wheel bearings from shock damage. As soon as the drum moves then be very careful as you can crack it if it's not hard against the hub flange. It doesn't seem like the obvious thing to do but I was shown how to do this back in the days of cars with drum brakes all round - Morris Minor, A55 and 60, Ford Anglia, etc, etc. It nearly always loosens them and I've never broken one doing it.

The rear drums are prone to developing a wear lip on the inner edge which, even with the hand brake cables completely slackened off, can make the drum difficult to remove. If you have this problem then screw a couple of the wheel bolts into their holes but only by two or three turns - so not tightened down - and slip a strong screwdriver under one edge of the drum between it and the back plate and lever the drum towards you. At the same time use the copper or leather mallet to hit the opposite side of the outside of the drum to encourage it to tilt. Once the drum is sitting at an angle to the hub and you can see the edge of one of the linings peeking out from the drum then you can use another screwdriver/tyre lever/ or whatever lodged against the wheel bolts, to turn the drum and "walk" it's lip over the shoes. If you try to remove a really stubborn one simply by levering then often the shoes get stuck under the lip and you'll damage stuff or simply not be able to remove it. However, by encouraging the drum to tilt in relation to the linings and then rotating it as you try to pull it off usually "walks" it over the ridge. It'll be quite tight to turn though so you need a big long and robust screwdriver.

My cars all get serviced every year and part of that is removing the rear drums - where drums are fitted - and filing/grinding off any lip which makes it a breeze to remove them the next year.

 

[PuntoHowTo]

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 had 100K miles on the rear shoes on my 2004 Punto when I finally replaced them, and only because I got nervous and decided I didn't want to continue driving on 100K mile brake shoes.

As Jock pointed out the bond between the friction material and the backing plate can fail, also after 100k things start welding themselves together with rust.

On fiat's they have never been an issue for me to get the drum off, just winding the adjuster back. I am not sure how much benefit you get from opening the bleed nipple as then you have the hassle of bleeding the brakes afterwards.

 

[Ralf S.]

Rear shoes do seem to last just about "for ever". When you get the drum off have a very careful look at the bonding between the friction lining and metal shoe, I've seen more than one where the bond was failing.

Probably not impossible to wind back the self adjuster through a bolt hole, but not easy and you risk damaging the mechanism. I like to completely disconnect, or at least wind back, the handbrake cables until they are really slack thus ensuring the shoes are completely returned against the stops. If the drum is seized to the hub, by which I mean not freeing off at all rather than sticking on the shoes, then take a hammer (a 1lb ball pein works for me) and strike the drum on it's face between the holes for the wheel securing bolts - so at right angles to the axis of the axle. So not on the outside of the drum as you'd think normal. The shock usually frees the drum. As soon as it starts to move swop the ball pein for a copper or leather mallet and hit the drum on it's edge which will tend to tilt it and further free it. As long as the drum is still hard against the hub you can nit it really pretty hard without any damage being done but I prefer to hit it moderately hard several times to spare the wheel bearings from shock damage. As soon as the drum moves then be very careful as you can crack it if it's not hard against the hub flange. It doesn't seem like the obvious thing to do but I was shown how to do this back in the days of cars with drum brakes all round - Morris Minor, A55 and 60, Ford Anglia, etc, etc. It nearly always loosens them and I've never broken one doing it.

We will know, if Jock is ever abducted by Aliens; His posts will not include reminiscences of old Austin models that nobody still alive even knows what they were...


Ralf S.

 

[Pugglt Auld Jock]

I had 100K miles on the rear shoes on my 2004 Punto when I finally replaced them, and only because I got nervous and decided I didn't want to continue driving on 100K mile brake shoes.

As Jock pointed out the bond between the friction material and the backing plate can fail, also after 100k things start welding themselves together with rust.

Becky's were starting to delaminate at about 11 years old and 65.000 miles

On fiat's they have never been an issue for me to get the drum off, just winding the adjuster back. I am not sure how much benefit you get from opening the bleed nipple as then you have the hassle of bleeding the brakes afterwards.

I can't see any need to slacken the bleed nipple either? there is nothing to stop the pistons retracting if needed - the fluid would simply be forced back into the master cylinder reservoir. Being able to wind the sef adjuster back would be of far more benefit.

 

[Pugglt Auld Jock]

We will know, if Jock is ever abducted by Aliens; His posts will not include reminiscences of old Austin models that nobody still alive even knows what they were...


Ralf S.

Ha, ha. I was just trying to demonstrate that it's a technique that's been around for many years. D'you know? I've tried for years to do that "Spock" thing with the fingers, just can't do it!

 

[steveras57]

Ha, ha. I was just trying to demonstrate that it's a technique that's been around for many years. D'you know? I've tried for years to do that "Spock" thing with the fingers, just can't do it!

At our age you need to be careful just like the cars there is a fair chance of snapping something!.

 

[Pugglt Auld Jock]

At our age you need to be careful just like the cars there is a fair chance of snapping something!.

That's why I'm not allowed to ride motor cycles any more - Mrs J says that at my age I won't bounce any more if I fall off!

 

[steveras57]

That's why I'm not allowed to ride motor cycles any more - Mrs J says that at my age I won't bounce any more if I fall off!

I still have 7 of the dam things! -wifey dont seam to mind maybe the insurance pay-out is quite good?