29 replies to this topic

[Spider]

I only ever fit the shields on period restorations.

I've found they cause grief from holding stones or the fixing tabs breaking. They also hold the heat in the disc longer too. I've never found them to have any effect on wet roads etc in regards to keeping the disc any dryer.

 

Generally, it's a no from me.

[Bobbins]

Thank you all for your very helpful replies. I’m tending to think that I will assemble the from end without them and fit them later if there’s any issues, brakes pulling to one side etc.
When finished the car will be summer use only, I gave up on a Mini for all seasons 40 years ago, although I do intend on some sizeable trips onto the continent so reliability will be massively important.

[Spider]

I did mean to add to my last that for what ever it's worth, there was a number of locally produced cars we had here (not Minis) that were never fitted with Shields, eg, Holden HQ to HZ is one that comes to mind that never had them.

[roblightbody]

Ever since I bought my first disc-braked Mini, exactly 60 years ago this week - a new 998 Cooper, I have removed the disc shields to improve brake cooling, eliminate a source of rusting components and prevent bits of grit from getting jammed between shield and disc.
They are really unnecessary.

So why does absolutely every new car have them?

[stuart bowes]

I'll be putting mine on because...

 

- as already said they must have some purpose otherwise why fit them in the first place

- in England it rains a lot

- if it comes to selling it looks 'right' being more complete I suppose

- I've already gone to the effort of cleaning them up and painting them

- it's not a high powered build so extra cooling won't be an issue

 

the only one thing I'd agree with as a negative really is potentially stones could get lodged in there. granted, but that's never happened to me with any car I've ever owned and they've all had shields

 

I might make a couple of stronger brackets though because reading above they apparently can be a point of failure

 

but that's not to say I disagree with anyone wants to take theirs off or anything 

Edited by stuart bowes, 26 June 2024 - 12:01 PM.

[sonscar]

My 2008 Kia does not have them.I removed them from all my classics and have not experienced any problems.YMMV,Steve

[imack]

Disc back plates on modern cars do little to prevent spray from the roads getting onto the inner face of the discs. Both my cars have numerous gaping great cutouts in the backplate exposing the disc.
I've never run backplate on my minis. Never noticed any issues in wet conditions.

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Edited by imack, 26 June 2024 - 04:27 PM.

[lsto]

My car is a daily. I fitted them as I do a lot of motorway driving, in my head it keeps water, road detritus and stray grease from the suspension away from the disks.
Wether it actually makes any difference, God only knows.

[bobyg]

The first time I used 'S' discs with no shields, on a Mini in the 1960's on a wet day I nearly went into a hedge. If you don't use the brake shields, cut a vertical slot in the pads (Girling DS 11 race pads in my case) with a hacksaw as some Fords used to have. This immediately clears the water and I did 80,000 miles or more with no problem in the 60's and 70's. We all did that at the time. Warning, be careful. Unless you use very good quality pads they could come apart,!!

[Spider]

Out of curiosity I looked up in one of my engineering design books why shields are fitted to get an engineering reason for them.

 

Before I pass on what it said, I'll just add that there was a whole chapter on Brake Drum design, another covering Disc Rotors and a very lengthy chapter for Calipers.

 

On Disc Shields there was barely one paragraph. While there was a little waffle, what it boiled down to was  " to reduce disc rotor wear and scoring from road debris, generally not used in Motor Sports ".

 

I thought this maybe of interest here.

[bpirie1000]

The spray suppression capacity of the back Sheild's is huge.

These days there are so many air ducts under and in bumpers these are also shaped for air cooling and direct the colder forced airs through the bumpers and into the brakes.

Not only to dissipate the heat but to remove the brake dust and just stay cool


But I have absolutely jo idea why newer cars have gone for the alloy back plate with the steel hub... just a metal disaster after a couple of years. Where the metals react together.... thanks engineers... just brilliant...

Goes with my theory of cars only being engineered to last around 4 years then be recycled into baked beans tins...or the plastics recycled into 2nd use plastics...

Edited by bpirie1000, 11 August 2024 - 04:51 AM.

[unburntfuelinthemorning]

Out of curiosity I looked up in one of my engineering design books why shields are fitted to get an engineering reason for them.

 

Before I pass on what it said, I'll just add that there was a whole chapter on Brake Drum design, another covering Disc Rotors and a very lengthy chapter for Calipers.

 

On Disc Shields there was barely one paragraph. While there was a little waffle, what it boiled down to was  " to reduce disc rotor wear and scoring from road debris, generally not used in Motor Sports ".

 

I thought this maybe of interest here.

Sounds like an interesting book.  What is it?

[unburntfuelinthemorning]

I don't personally find any problem with brake operation in wet conditions despite having no disc shields.  The water spray is constantly being centrifuged off of the disc by the rotation of the disc when the vehicle is in motion - especially at motorway speeds.  

[Midas Mk1]

The first time I used 'S' discs with no shields, on a Mini in the 1960's on a wet day I nearly went into a hedge. If you don't use the brake shields, cut a vertical slot in the pads (Girling DS 11 race pads in my case) with a hacksaw as some Fords used to have. This immediately clears the water and I did 80,000 miles or more with no problem in the 60's and 70's. We all did that at the time. Warning, be careful. Unless you use very good quality pads they could come apart,!!

That's more from using race pads, as they tend not to work until hot, rather than lack of shields.

 

[Cooperman]

 

The first time I used 'S' discs with no shields, on a Mini in the 1960's on a wet day I nearly went into a hedge. If you don't use the brake shields, cut a vertical slot in the pads (Girling DS 11 race pads in my case) with a hacksaw as some Fords used to have. This immediately clears the water and I did 80,000 miles or more with no problem in the 60's and 70's. We all did that at the time. Warning, be careful. Unless you use very good quality pads they could come apart,!!

That's more from using race pads, as they tend not to work until hot, rather than lack of shields.

 

 

That's quite right.

The older race pads, the copper/asbestos ones. were poor when cold, but modern Pad materials, especially the Carbon-Metallic ones, are fine from cold and damp right up to red hot discs.