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Discussion Starter · #1 · (Edited)
R53 Front Brakes Upgrade – ‘Big Brake’ Options

Don’t know if anyone is interested on here, but I have set about this on my 2005 R53, so here it is. Long one I’m afraid.

This is an attempt to help those who want to upgrade their Gen 1 front brakes to the more effective Gen 2 front brakes (including the JCW alternatives). It deals with the calipers and carriers. There are many aftermarket caliper upgrades available but this sticks to BMW OEM. The manufacturers of these are ATE and TRW.

So What’s the Problem? Why Do It?
It is widely accepted that the Gen 1 brakes are unsatisfactory, particularly on R53 Cooper S models. The standard brakes lack stopping power, feel and are prone to fading with harder, more spirited use. The easiest and least expensive improvement is to fit the Gen 2 Cooper S front brakes.

Change the Rears?
The rears on Gen 1 and Gen 2 (including both JCW kits) use the same 259mm solid disc set up. Most advice is that it is not worth changing/upgrading the rear brake calipers and disc size, although clearly changes to discs and pads may be fitted. It is simply not worth the effort as the original R53 calipers are perfectly acceptable on the rear.

What is Involved?
Upgrading the Gen 1 front brakes to Gen 2 brakes involves changing:
• Calipers
• Carrier brackets
• Discs
• Pads
• Brake hoses

Gen 1 Standard Fronts
Exactly the same braking system was fitted to all Gen 1 MINIs, One, Convertible, Cooper and Cooper S, from launch to September 2006 (later for convertible), when the Gen 2 R56 model was introduced.
The fronts use a single piston sliding caliper system with a 48mm diameter piston acting on 276mm solid vented discs.
Gen 1 JCW Upgrade Kit
The JCW engineers picked a single piston sliding caliper with a larger 54mm piston and 294mm disc. This provided a bigger piston in the caliper for more ‘squeeze’ and a larger ‘swept area’. This was the set of front brakes that the R53 Cooper S should have had all along.
This kit just bolts on the existing hub and has the same ‘banjo’ hose fitting, so the standard R53 hoses are fine and can be used with the JCW caliper without modification.

The JCW kit was available with either a solid vented disc or a grooved and holed vented disc. The ‘holes’ were not drilled but formed in the casting process.
The JCW kit has red painted front calipers with the JCW sticker. The rear calipers were not painted red and neither the rear disc nor caliper was changed.
They were supplied with upgraded pads by Jurid for both front and rear brakes.
Not all cars with the JCW engine upgrade were fitted with the JCW brake upgrade - some had the JCW engine conversion but still with standard R53 brakes.
The JCW brake kit is no longer available new from main dealers.

Gen 2 Front Calipers
The Gen 2, from September 2006, uses a single piston sliding caliper with a 54mm piston caliper across the whole range. They have a standard electroplate finish. The brake hose fitting on the Gen 2 calipers is the ‘screw in’ type, not the ‘banjo’ type used on the Gen 1 calipers.
But the S carriers and disc size differs – see next.

Gen 2 Non S Discs & Carriers
The One, Diesel and Cooper have a 280mm disc. They all use the same carrier bracket fitted on both sides, non-handed (denoted TRW 15, stamped on the carrier). They have a standard electroplate finish.

Gen 2 R56 Cooper S Discs & Carriers
The R56 Cooper S has a 294mm disc – the same disc size as the R53 JCW kit. The 294mm disc is accommodated by using a different carrier bracket (denoted TRW 16 for the S, stamped on the carrier) to the non S models and they are handed left and right.
The S caliper carriers look identical but the sliding pins are set up differently with one of the pins having a rubber like part on it to stop the caliper sliding too much, thus making the caliper carrier handed L or R. They have a standard electroplate finish.

Front Brake Hoses for R56 Calipers
There is one significant difference with the R56 caliper when fitting to an R53 or any Gen 1 MINI. The brake hose fitting is a ‘screw in’ type not ‘banjo’. So you must use R56 front brake hoses when fitting the R56 calipers. They fit easily to the R53 models.
At the same time you may also wish to fit braided brake hoses front and rear.

Paint and Stickers
If you use the Gen 2 Cooper S electroplated items you won’t have the red calipers and JCW sticker. But you can get these professionally finished in red (or another colour of your choice) by the various companies that specialise in this. One such is Bigg Red. Or do it yourself.
It is also possible to buy the JCW stickers on eBay. Main dealers do not sell them. These should be affixed to the calipers after powder coating and then the whole caliper is lacquered to protect the sticker – make sure this is in high temperature lacquer.

Master Cylinder
The R53 has a relatively small brake master cylinder. So you may find the top of the pedal is softer once you have increased the size of the pistons in the calipers. It is not a major issue and does not impact on the enjoyment of the car.
This can be fixed. The larger R56 master cylinder does not fit on the R53. They are visibly different.

Gen 2 Cooper S or Gen 1 JCW Upgrade Kit?
So you can see that the Gen 1 JCW brake upgrade kit is basically the same as standard Gen 2 Cooper S brakes. The actual engineered solution is identical. Fitting standard Gen 2 Cooper S fronts will provide the same improvement as the Gen 1 JCW kit. It will be significantly less expensive, unless you can find a used JCW kit for sensible money.

Buying New
1) Buy the R56 S calipers and carriers from a MINI main dealer
2) Buy the R56 S calipers and carriers from a factor or on-line

The R56 Cooper S prices are (June 2017) for new from main dealer, inc. VAT – they won’t give out part numbers, but hopefully these are the correct OE numbers:
Caliper N/S/F £256.01
Caliper O/S/F £236.00
Carrier N/S/F £80.00
Carrier O/S/F £80.00
Hoses (front pair) £72.22
Total: £724.23

R56 Cooper S prices, from factors on-line – with the TRW part numbers:
Caliper N/S/F TRW BHW907 £67.46
Caliper O/S/F TRW BHW908 £67.46
Carrier N/S/F TRW BDA947 £44.96
Carrier O/S/F TRW BDA946 £41.36
Hoses (braided by HEL or Goodridge) £40 a pair.
Total: £261.24

So the TRW solution is £460 cheaper. Same product. No brainer.

Buying Used
You can buy the calipers and carriers used from any of the normal sources – breakers, eBay, forums.
When buying second hand parts you need the Cooper S caliper carriers but the actual R56 calipers are all the same 54mm piston type. So you can acquire any Gen 2 caliper and couple it with the R56 Cooper S carrier brackets for the big brake upgrade.

Discs and Pads
The disc and pad choice is down to you. Just make sure they are the 294mm items (for the Gen 2 Cooper S). There are many permutations of disc and pad available from a myriad of aftermarket manufacturers. Huge choice, many opinions, depends on what you are using the car for.

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2,316 Posts
Discussion Starter · #4 ·
Nice one Nigel. I'll stick to my occasional left foot braking which seems to be my big brakes alternative and works quite well. hehehe
Jeffo, left foot braking. I haven't tried but someone told me the other day that in a Mini if you put the brake on with your left foot the software won't let you apply the throttle. Is that true? I've done it in other cars when people are tailgating me, light the brake lights and accelerate at the same time.

Incidentally people, if I've got anything wrong or need to add anything, please do let me know and I'll update it.

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59 Posts
Hi Nigel,
I've no idea if thats the case when the software won't let one apply throttle when also braking? I'll be looking into that and whether its only with certain models of mini's or not.
It seems to work great for me maybe cause I lift off the accelerator before using my left foot to get enhanced braking power. I've not tried it where I'm covering my accelerator pedal a little whilst applying the brakes though. I'll be trying it out before updating the news here.
These days I mostly don't do a lot of braking hard apart from certain scenarios that warrant it. Just when you think your right foot has given all its got, you'd be surprised how much more stopping power ones left foot has over the right foot. :)

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2,316 Posts
Discussion Starter · #8 ·
Nice read Nigel, have you any idea what the difference is in Master Cylinder capacity on the R53 and the R56 ? or by fitting braided lines overcomes the reduced volume of fluid ?
I've tried to find out. No definitive answer but someone reckoned it was something like 21.8 bore on R53 and maybe 22.4 on the R56? Don't think there is much difference though. You can't fit an R56 master, they are completely different, see pic. R56 top, R53 bottom.

JohnnyC is spot on. No-one bothers about it. Even the racy, pacy chaps on MT. I'm told talking to people who have done it, and all have left the master cylinder as is, that you get a little more intial peddle travel, but it works fine. As JohnnyC says, the JCW engineers didn't think it was worth bothering with.

When at 'my man's' the other day changing the fuel fuel filter and freeing off the selector cables at the gearbox end (what an improvement, the change was awfull, so heavy!) we chucked on a set of new front EBC pads he had lying about. Not anything special, think they call then 'OE' equivalent. Just that has improved things considerably for road use.


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59 Posts
I've just tried the braking with left foot while right foot is covering the accelerator and it works fine between the two.

Like you, I sometimes use my left foot to give the brakes a quick jab if the car behind is far too close to me.

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110 Posts
Windy, Is it a major improvement? Maybe your car had the big brakes when you got it so you can't compare? Do you track it or just road use?
Brakes had been done prior to me getting the car however compared to standard MCS brakes that I had tried it is a noticeable improvement, increased braking power and more resistant to fade though this is still evident under real hard braking, I also have uprated cross drilled grooved rear discs. Only used on the road.

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1,203 Posts
Just came across this video on YouTube, the only thing I can see that he missed in the video was to clean the disc rotors with brake cleaner and grease the slider pins.
He made a rather large error, he's using EBC brake pads :big_grin::eeksurprise::eeksurprise::eeksurprise::eeksurprise::big_grin:

Some discs though specify that they shouldn't be wiped clean upon installation (Ferrodo discs are one that I can think of).

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1,203 Posts
I didn't go for 'new' calipers, but didn't want tatty old ones either. So I went with refurbished from Brakes International.
But they looked pretty much brand new anyway (as every refurbished caliper I've bought), worked out at £50 per caliper (old ones have to be returned).
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