Hi guys, I recently tried to change the brakes pads & discs on my 06 1.2 dynamic, but the bolts that hold the caliper bracket to the wheel hub were rounded so I was only able to switch out the pads.

Does anyone know where to buy replacement bolts online?

I can't seem to upload a photo of the bolts I'm referring to, but hopefully I've made it clear.

I'm looking at buying a bolt extractor set soon so I'll need some replacement bolts to make future jobs easier. Would be greatly appreciated if anyone can help, been looking around for a while and haven't found anything.

Cheers

Main dealer

I don't know whether it applies to the non-vented disks on the petrol model, but the vented disks on the multijet can be wriggled out without removing the carrier bracket - just remove the caliper itself and hang it out of the way?

they are a standard high tensile flanged bolt. You can buy a kit of several sizes that do the majority of cars. Carlson or something like that ?


Unfortunately they are fitted with thread lock


I doubt they will undo easily with the application of heat


I might be confusing with a different vehicle but i thought it was just possible with the pads out to slid the discs out. But i might be confusing a different car.

I took them out last time i replaced my discs and pads. The bolts were high tensile 8.8 with a thread length of 22mm and pitch of 1.25 (M10x1.25). Can't remember if they had thread lock on but they came out fine.

The M8 bolts which hold the brake pad carrier is usually supplied with the brake pads. The OEM might be 10.9 high tensile. You'll need a good anti seize top to bottom on the threads.

The bolts holding the caliper to the hub might be socket head and again high tensile. I believe M10 fine, but I've never had to replace them.

Phone Shop 4 Parts as they dont list anything on the website.

Bolts grades
https://www.wrightsautosupplies.co.uk/different-grades-of-high-tensile-bolts/

Ians Panda said:

I took them out last time i replaced my discs and pads. The bolts were high tensile 8.8 with a thread length of 22mm and pitch of 1.25 (M10x1.25). Can't remember if they had thread lock on but they came out fine.

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useful information

Ians Panda said:

Can't remember if they had thread lock on but they came out fine.

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I took mine out a few days after I bought my car new and can confirm that they are fitted using threadlock at the factory. No problem removing them on a new car, but if left in for a few years, I'd expect them to be 'challenging'.

Becky (1.2 Panda Dynamic Eco) needed a bit of disc "fettling" when we bought her at around 7 years old. Because I needed to remove the discs I took the caliper carriers off (didn't think to check if the discs can be "wriggled" out with them in place - must check that out next time I'm doing pads etc) The caliper carrier bolts were very tight but came out fine with a single hex, 6 point, impact socket and my old 14" Britool power bar. Wire brushed and a wee bit of blue thread lock on installation. I think it likely a bi hex, 12 point, socket might have rounded them off.

Cheers for the info guys! The car is booked in for a possible wheel bearing replacement soon, so I've asked the garage if they can also replace the bolts too(since they might need to come out anyway). After that I'll try Trimdoner's suggestion when doing the brake discs

DaveMcT said:

You'll need a good anti seize top to bottom on the threads.

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Hi Dave. I may have misunderstood what you are advising here. Are you advising the application of antiseize to caliper and/or carrier retaining bolts? I can see the temptation to do this - to avoid possible future seizing problems and make future dismantling easier - However I would strongly advise against it on the grounds that these parts are subject to extreme vibrational forces (just look at the condition of our roads these days) and anything which might encourage a component to slacken, especially brakes, should be avoided. I always apply blue thread locker, partly because it will tend to stop things coming undone but also because it seals the threads against water ingress and thus corrosion of the threads.

Pugglt Auld Jock said:

Hi Dave. I may have misunderstood what you are advising here. Are you advising the application of antiseize to caliper and/or carrier retaining bolts? I can see the temptation to do this - to avoid possible future seizing problems and make future dismantling easier - However I would strongly advise against it on the grounds that these parts are subject to extreme vibrational forces (just look at the condition of our roads these days) and anything which might encourage a component to slacken, especially brakes, should be avoided. I always apply blue thread locker, partly because it will tend to stop things coming undone but also because it seals the threads against water ingress and thus corrosion of the threads.

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correct


the exact opposite to what you need

Pugglt Auld Jock said:

Hi Dave. I may have misunderstood what you are advising here. Are you advising the application of antiseize to caliper and/or carrier retaining bolts? I can see the temptation to do this - to avoid possible future seizing problems and make future dismantling easier - However I would strongly advise against it on the grounds that these parts are subject to extreme vibrational forces (just look at the condition of our roads these days) and anything which might encourage a component to slacken, especially brakes, should be avoided. I always apply blue thread locker, partly because it will tend to stop things coming undone but also because it seals the threads against water ingress and thus corrosion of the threads.

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I would agree if wet were talking about greased threads. A good quality high solids anti seize will not lubricate the threads. I've never had one come loose ever and the same on pump and motor mounts when I worked in engineering with vibration 24/7. I have more than a few that were so stuck solid to be close to shearing before they loosened and at least one that sheared off.

Saying that, new M8 bolts for the brake pad carrier are supplied with a blue patch and blue thread lock should be used on refitting them.

DaveMcT said:

I would agree if wet were talking about greased threads. A good quality high solids anti seize will not lubricate the threads. I've never had one come loose ever and the same on pump and motor mounts when I worked in engineering with vibration 24/7. I have more than a few that were so stuck solid to be close to shearing before they loosened and at least one that sheared off.

Saying that, new M8 bolts for the brake pad carrier are supplied with a blue patch and blue thread lock should be used on refitting them.

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Thanks Dave. My "anti seize" arsenal consists of Copper, Aluminium and Ceramic based greases. A product with the properties of which you speak is not coming readily to my mind, but I'm always very keen to expand my knowledge base. Can you identify the products for me, I could see myself using something like this if there is zero risk of it causing the fixing to loosen in service.

odd

New bolts are supplied with thread lock (glue) already applied.

to work properly the other part has to be clean. Often requiring degreased. Normally with isopropyl

I'm not sure the argument one has never fallen out on me holds water ?

I have never had a starter motor bolt fall out and that hasn't got any thread lock on it at all but if it did my life or that of others are less likely to be affected

I must be missing something obvious.

I put anti size on these bolts as well and none ever worked loose
Mind you I've only been doing it the last 4 years or so but still not not had an issue

koalar said:

I must be missing something obvious.

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We live in a world where manufacturers operate under the constant threat of litigation should something go wrong.

If you degrease eveything, use new bolts, threadlock, assemble dry, and tighten to the manufacturers recommended torque setting. there is (almost) zero chance of these bolts coming loose in service. This is the manufacturers recommended procedure for replacing the bolts. If you then subsequently want to remove them in five years time, there will be a reasonable chance that they won't easily come loose when you want them to. With air tools and high quality impact sockets you'll likely be OK; the odds are less good with a breaker bar and a draper socket set.

Some folks are concerned they may not be able to easily undo these bolts in the future, so not everyone follows the manufacturers procedure.

It isn't appropriate for a moderator to condone this.

koalar said:

I have never had a starter motor bolt fall out and that hasn't got any thread lock on it at all

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I've never had any greased bolt, tightened to 2/3 of the dry torque setting, come loose in service. If you go over the 2/3 figure, there is a serious risk of overtightening and taking the thread beyond its elastic limit; this is likely to result in it subsequently becoming loose.

jrkitching said:

We live in a world where manufacturers operate under the constant threat of litigation should something go wrong.

If you degrease eveything, use new bolts, threadlock, assemble dry, and tighten to the manufacturers recommended torque setting. there is (almost) zero chance of these bolts coming loose in service. This is the manufacturers recommended procedure for replacing the bolts. If you then subsequently want to remove them in five years time, there will be a reasonable chance that they won't easily come loose when you want them to. With air tools and high quality impact sockets you'll likely be OK; the odds are less good with a breaker bar and a draper socket set.

Some folks are concerned they may not be able to easily undo these bolts in the future, so not everyone follows the manufacturers procedure.

It isn't appropriate for a moderator to condone this.



I've never had any greased bolt, tightened to 2/3 of the dry torque setting, come loose in service. If you go over the 2/3 figure, there is a serious risk of overtightening and taking the thread beyond its elastic limit; this is likely to result in it subsequently becoming loose.

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Thanks for your input

but still don't get why you wouldn't install these critical bolts as per recommendation

thread locked bolts on the outside of a 10 year Old car are about the only ones that don't internally corrode up

the thread lock covers the gaps and spaces with a kind of plastic covering sealing it from water.

Perhaps there's also the insurance factor to consider too? difficult perhaps to justify the anti seize, which is not recommended by the manufacturer, after "the event" when an "independent automotive expert" has submitted a damning report to the court?

Anti seize paste is not a lubricant. Decent quality products also do not need to have the recommended torque settings reduced. Cheap jack copper-coloured grease from Halfords is another matter.

Ah but what about cylinder had bolts, which are very fussy?
Indeed, but once the cylinder head has been removed some (if not al)l of the bolt holes will be contaminated with oil and coolant. This must be cleaned out to avoid the bolts hydraulic locking into their holes. However. I defy anyone to clean the threads to the state they were in the factory. Even there, machining coolants will remain in the holes which will lubricate the threads to some extent.

Going back to brake mounting bolts, the forces in use put the metal in shear. The stretch forces are provided by the tightening torque only. These not added-to when the brakes are used.

On motorcycles, the callipers and the mounting brackets are aluminium alloy often cast. If they are assembled without an anti seize paste, the bolts risk shearing off when you try to remove them due to alloy corrosion seizing the threads. Then what? I've had 1970s bikes, through to East German and modern day European and Japanese. The brake mounting bolts have never come loose. Why should they? Just as with a car the bolts take the brake loads in shear. The threads merely provide the clamping force to keep the caliper in place and aligned to the disc.

I would add that if the brake mounting bolts loosening was a genuine issue, they would be fitted with locking split pins. Then what about the rear stub axles? or every other fastener on the car suspension and chassis?