That grease-monkey feel

[FordPrefect8]

I have replaced discs and brake pads plus calipers overhaul on two Mk2 Jazzes during recent heatwave. One of them didn't have anti-seize anything applied, my 400 Nm impact wrench couldn't deal with caliper bolts
I'm not even mentioning disc holding screws, those I had to extract with manual impact driver and hammer on both cars, that's 16 screws overall each taking 30-60 mins.

Despite many rust induced rage fits, it's still great fun overall. New coated discs look amazing and braking is more even throughout the heat cycle. There was also a matter of my partner's Honda rear right brake being completely seized which didn't even show when driving!

Also I saved quite a few hundreds of pounds.

[culzean]

I have replaced discs and brake pads plus calipers overhaul on two Mk2 Jazzes during recent heatwave. One of them didn't have anti-seize anything applied, my 400 Nm impact wrench couldn't deal with caliper bolts
I'm not even mentioning disc holding screws, those I had to extract with manual impact driver and hammer on both cars, that's 16 screws overall each taking 30-60 mins.

Despite many rust induced rage fits, it's still great fun overall. New coated discs look amazing and braking is more even throughout the heat cycle. There was also a matter of my partner's Honda rear right brake being completely seized which didn't even show when driving!

Also I saved quite a few hundreds of pounds.

Good work, never had a powered impact wrench, never needed one - a manual impact one ( powered by a 4lb lump hammer) and a 600 mm breaker bar ( with full hex sockets, not those double hex head wreckers ).  If I used a powered impact wrench I would feel compelled to wear a blue and white striped apron while working... https://www.restaurantsupplystore.co.uk/whites-butchers-apron-navy-stripe?source=googlebase&kw=&ci=13146694916&network=s&cid=172061345&aid=4987707602&tid=pla-4581390076041978&dev=c&mt=e&pid=318&country=GB&source=bing&msclkid=0066d6987ae81d699a95b662bac05fa4&utm_source=bing&utm_medium=cpc&utm_campaign=Shopping&utm_term=4581390076041978&utm_content=All%20Products

I just threw the disc retainer screws away,  with 4 x M12 studs holding the discs in place why are they even there ( only to hold the disc in place during assembly at Honda factory ).

Totally lost count of the money saved over many years by doing own work on cars and bikes ( and knowing it has actually been done and which parts used ) is priceless...

[FordPrefect8]

Totally lost count of the money saved over many years by doing own work on cars and bikes ( and knowing it has actually been done and which parts used ) is priceless...

Especially knowing that you used exactly what you paid for, agree all the way.

Also, since there are no labour costs, we could invest in upgrade parts.

[cornishpasty]

Yes, those JIS Japanese standard cross head disc screws are a pain, even with the correct JIS impact driver. Torx screws would be a much better solution imho.

[Johncb500]

Strange that they still use disc securing screws,

I thought they had gone 35 years ago

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[FordPrefect8]

Yes, those JIS Japanese standard cross head disc screws are a pain, even with the correct JIS impact driver. Torx screws would be a much better solution imho.

Totally, seems like mechanic who did discs last time did not realise the difference between JIS and Philips and then re-used them
Nearly all of them were busted, had to use shank JIS bits and very sharp strong blows with the mallet.

Torx would definitely be a much better solution here.

[FordPrefect8]

Strange that they still use disc securing screws,

I thought they had gone 35 years ago

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Nope, still there

[culzean]

I find that tightening the disc retaining screws a bit ( to break the seating / rust on the huge area of countersink head ) then reversing the impact driver and slacking off seems to work - then chuck screws in the bin and don't replace them....

[FordPrefect8]

I find that tightening the disc retaining screws a bit ( to break the seating / rust on the huge area of countersink head ) then reversing the impact driver and slacking off seems to work - then chuck screws in the bin and don't replace them....

Interesting, I'll try that next time. For now I've put new coated screws supplied with the set with generous amount of copaslip.

I can see how there would be no reason to have them other than initially holding them in place while I install the caliper.

[cornishpasty]

A sad state of affairs when a mechanic (technician) does not know the difference between JIS, Phillips, or posidriv. That's why some do our own work, listen and post on this forum. Long may it continue.

[Kenneve]

As someone who has worked in the Car Manufacturing industry, for all of my working life, may I be permitted to make one or two observations.
The use of the Disc fixing screws is essential for the following reasons:-

In the factory, the Disc is assembled to the Hub in clean conditions and the screws are used to ensure that the disc is properly located against its location face. Run-out (wobble) of the assembled disc is held to very tight limits, in the order of 0.1mm total Run-out at 300mm diameter. (smaller disc would have a proportionately smaller tolerance).
This is done to ensure smooth vibration free braking.

Now, consider what would happen at the roadside, should you wish to change a wheel, if these screws were not fitted.
When you take the wheel off, the Disc is no longer fixed to the Hub, because you have removed all the wheelnuts  and so could easily move on its register, and away from its location face. You may say so what! Well, you are longer working in clean conditions and some road dirt could easily find its way into the location face joint.
Thus, when you assemble your spare wheel and do up the nuts, there is a distinct possibility of excessive Disc run-out occurring, leading to possibly dangerous vibration when braking.

Certainly the move to Torx or maybe Allen key head would be desirable but rest assured, the use of these screws is very important.

[culzean]

As someone who has worked in the Car Manufacturing industry, for all of my working life, may I be permitted to make one or two observations.
The use of the Disc fixing screws is essential for the following reasons:-

In the factory, the Disc is assembled to the Hub in clean conditions and the screws are used to ensure that the disc is properly located against its location face. Run-out (wobble) of the assembled disc is held to very tight limits, in the order of 0.1mm total Run-out at 300mm diameter. (smaller disc would have a proportionately smaller tolerance).
This is done to ensure smooth vibration free braking.

Now, consider what would happen at the roadside, should you wish to change a wheel, if these screws were not fitted.
When you take the wheel off, the Disc is no longer fixed to the Hub, because you have removed all the wheelnuts  and so could easily move on its register, and away from its location face. You may say so what! Well, you are longer working in clean conditions and some road dirt could easily find its way into the location face joint.
Thus, when you assemble your spare wheel and do up the nuts, there is a distinct possibility of excessive Disc run-out occurring, leading to possibly dangerous vibration when braking.

Certainly the move to Torx or maybe Allen key head would be desirable but rest assured, the use of these screws is very important.

Every time I have ever removed a disc it has required jacking away from hub with the 2 x M8 holes that are there for that purpose, once a disc has been on for a short time it is basically bonded to the hub mounting face with ferrous oxide       

[Kenneve]

Maybe with old bangers and conventional cast iron discs,  but there are several alternative materials available nowadays such as, ceramic, stainless steel, aluminium matrix, etc that won’t stick to the hub.
Even a brand new car can get a puncture.

[Johncb500]

As someone who has worked in the Car Manufacturing industry, for all of my working life, may I be permitted to make one or two observations.
The use of the Disc fixing screws is essential for the following reasons:-

In the factory, the Disc is assembled to the Hub in clean conditions and the screws are used to ensure that the disc is properly located against its location face. Run-out (wobble) of the assembled disc is held to very tight limits, in the order of 0.1mm total Run-out at 300mm diameter. (smaller disc would have a proportionately smaller tolerance).
This is done to ensure smooth vibration free braking.

Now, consider what would happen at the roadside, should you wish to change a wheel, if these screws were not fitted.
When you take the wheel off, the Disc is no longer fixed to the Hub, because you have removed all the wheelnuts  and so could easily move on its register, and away from its location face. You may say so what! Well, you are longer working in clean conditions and some road dirt could easily find its way into the location face joint.
Thus, when you assemble your spare wheel and do up the nuts, there is a distinct possibility of excessive Disc run-out occurring, leading to possibly dangerous vibration when braking.

Certainly the move to Torx or maybe Allen key head would be desirable but rest assured, the use of these screws is very important.

Thanks for this,

Back in the mid 80s I had a Toyota   ,and the discs only fitted on the studs, no screws,

They were a snug fit, a simple wheel change would not appear to  disturb the disc,

I figured on small relatively light vehicles such as Jazz,Corolla etc. It would be perfectly ok.

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[culzean]

Maybe with old bangers and conventional cast iron discs,  but there are several alternative materials available nowadays such as, ceramic, stainless steel, aluminium matrix, etc that won’t stick to the hub.
Even a brand new car can get a puncture.

Even more recent cars that I have worked on ( never had any with exotic disc materials that didn't succumb to oxygen and water + salt ).