Brakes - Fitting Discs and Required Ancillaries

What you actually need for the disc/drum conversion is pretty straightforward. Disconnect the steering arms, top and bottom swivel-pins, CV joint, and flexible brake pipes at the subframe - that’s it. There are, however, a number of ancillaries to consider.

Basics

Basics Fitting discs designed for the Mini is easy enough. Just make sure you use CV gaiters for the disc-brake set-up - these have a different bellows shape to stop the gaiter rubbing the inside of the hub. The drum type will rub, then split, shedding grease all over the place. Moly grease is mighty mucky stuff to deal with and doesn't assist braking at all! A tip for racers - to stop the gaiters over-expanding when getting very hot and imitating the aforementioned, put either a decent sized split pin or (my favorite) a piece of very small bore pipe - as in the type supplied with WD40 aerosols, etc. - under the retaining strap on the drive shaft. This allows air to escape and return,

CONTENTS OF C-AJJ4028 BRAKE 7.5”DISC KIT LESS PROTECTOR SHIELDS

CONTENTS OF C-AJJ4028 BRAKE 7.5”DISC KIT (NO PROTECTOR SHIELDS)

1. 1 x 27H4656 CALIPER GENUINE AP R/H 
2. 1 x 27H4657 CALIPER GENUINE AP L/H 
3. 1 x FAM2390 HUB BARE R/H 
4. 1 x FAM2391 HUB BARE L/H 
5. 2 x 21A1270MS DRIVE FLANGE 
6. 2 x GBD101MS BRAKE DISC. etc.....

Brakes. Pad Types and Choices

I know I keep dragging this one out for an airing but it’s continually ignored by far too many folk - the only way to get the best from what you have is to be totally honest with yourself about your Min’s main usage. Delusions of grandeur cause severe disappointment, and tears before bedtime. Fitting a set of pads to your road Mini because you think you drive like Michael Schumacher, and your Mini’s built around a ‘race’ theme, with ‘race-spec’ brakes is going to get you into severe bother. Nine

Despite a particular pad type having a high ‘Mu’ designate doesn’t mean to say it’ll give you the best braking potential. They’re generally made in a harder compound so may also give unacceptable levels of disc wear, noise output (squeal), or judder. A pad that gives excellent performance at lower temperatures may have unacceptable pad wear, and create excessive corrosive dust.

So what you need is a pad tha...

Brakes - How They Work

This time we’re going to look at just how brakes do what they do, and ways to improve them. Without a doubt the most important point to get sorted at the outset is just what makes brakes do their thing - FRICTION. The sole purpose of the brake set-up on any vehicle .....

Brakes - Fundamental Considerations

When looking to increase their cars performance, most folks immediately turn to considering higher engine power outputs. Because of this pre-occupation brakes tend to slide down the improvements priority list. However, they are far more important - being able to accelerate at warp speed to hyper-space in the twinkling of an eye is all very well, but disastrous if you can’t stop. You will make a very big hole in the scenery, and possibly end up wearing an wooden over-coat. Getting the braking system sorted out can help to make the car quicker, as you will be able to more confidently, therefore maximising speed in any given situation. Being one of those ‘sciences’ used in the automotive industry I hope to shed some light on the subject as it's another of those where many questions from confused and mislead folks that clog up my e-mail board. The advent of the Metro, and the brakes used on it has spawned a lot of activity in this direction. It was soon discovered that they could b

Brakes - Pads, Function and Parameters

The past few years have witnessed a great deal of activity in the brake-swapping department by Mini enthusiasts world wide. The reasons are quite diverse, ranging from fashion to necessity. Some fit vented Metro 4 pot brakes because it’s the ‘in’ thing to do, giving max pose value. Some believe it’s a performance improvement, usually misguided by a misinformed vendor hell bent on making a sale. Some do it because they’ve been given a Metro, and their Mini’s endowed with drum-brakes. Some fit 7.5” S-type brakes because they want to fit 10” wheels on their late-type Mini. Some fit them because the racing discipline they compete in won’t allow anything else. Some even fit the disastrous 7” Cooper-type because it’s all they have. Whatever the reason or type of disc-brake set-up used, the effectiveness of the installation can be honed to perfection by the type of brake pads fitted. Indeed, using the correct brake pad on a current set-up could out perform any intended swap, such is their in

Brakes - Rear brake bias adjustment

When altering the front brake set-up away from the standard installation, it invariably alters the amount of rear brake bias needed to re-balance the cars brake balance.

The problems start occurring when folk graft alternative brake set-ups onto the front of their Minis. Be this 7.5" discs onto a previously drum-braked model, or going from current standard disc set-ups to one of the 4-pot varieties. The question then is 'what bore size rear wheel-cylinders do I need?' Unfortunately this isn't straightforward. Actually, that's not strictly true - more on this later. The pressure developed in the lines determines brake effectiveness - aside from disc size, pad type, co-efficient of friction, etc. that is. Understanding this may assist in choosing which way you should go for your particular set-up.

The basic facts you need to remember when dealing with brake pressures is how they are affected by the components you use.

Brakes - Silicone brake Fluid

To use or not to use - that is the question! BRAKES - Silicone brake fluid, to use or not to use - that is the question! Over more recent years I've had affair number of discussions on the use of silicone brake fluid as opposed to the more common type. I have to say some folk are vehemence in their belief that this stuff is 'the answer' to all kinds of brake maladies. Some time ago I contacted the two major brake specialists in this country (UK) to see what they had to say. Their reactions was as vehemence as those believers above. For what it's worth, I thought I'd spread the word according to the manufacturers - which happens to be similar to my limited experience with this 'liquid savior'. Some has heralded silicone-based brake fluid as being the last word in brake fluid, yet also brings a look of horror onto the faces of some. The classic car folk swear by it, particularly for vehicles that are not used much where brake seal failure can be experienced, and because it does not

Engineering - Consistent measurements

During a recent discussion with a few overseas Mini brethren - who were experiencing various engine-related problems - something cropped up that I have always taken as granted (in the sense of ' a standard for the application'); the matter of consistency in measurements.

Now we're not talking about the sort of measurements you make with a ruler, since discrepancies of a small nature don't tend to matter a whole lot. No, we're talking about the sort of measurements made with fine measuring instruments such as micrometers or vernier calipers.

Now, the discussion that was going on was with reference to the best clearance to run between the bore and piston for a given piston type for race or street purposes. I hade quoted figures that I generally use for both situations for forged and for cast piston types.

KNOW YOUR MINI TYPE

This is to help you understand which mini you own from a spare parts point of view. Officially There were only Mk1/Mk2 and Mk3 on sales brochures but the Mk4 was introduced by Keith Dodd in 1976 to help people understand the main parts changes. From here we eventually got to MK7

What mini do you own-Make your Mark from this list Confused what mini you own,...

SILICONE VALLEY

For some reason, I have recently had a spate of queries about this stuff. So I thought I'd do a quick tech thing on it, seeing as most of the little available information is seemingly misleading.

'Into the valley of death, rode the six hundred.........' No, this isn't about silicone microchips, or anything about computers at all. Having just done that stuff on disc brakes, it prompted me into thinking about the braking systems as a whole, one thing lead to another, and, well, and brake fluid. More exactly, silicone based brake fluid. For some reason, I have recently had a spate of queries about this stuff. So I thought I'd do a quick tech thing on it, seeing as most of the little available information is seemingly misleading. Silicone based brake fluid has been heralded by some as being the last word in brake fluid, yet also brings a look of horror onto the faces of some. Strange, eh?

SU Carbs - Poor idle quality

Something that crops up when any modifications are made to an engine - mainly in the form of improving induction and exhaust capability - is that of idle quality.

After applying aforementioned freer-breathing products to enhance power output, many complain that no matter what - including post rolling-road tuning - they can not get a satisfactory, steady idle setting. And this after checking for manifold/gasket air leaks and spindle to carb body play (usual suspect as the spindle wears quite dramatically over several thousand miles). There is one thing that is often over-looked - the air valve found on many later model cars. This sprung-loaded air valve is built into the butterfly, sometimes called a 'poppet' valve or anti-dive valve. It is primarily there to reduce emissions when the engine is on the over-run - closed throttle at speed, i.e. anything other than at idle and gearbox in neutral.

Suspension - Dampers, basic knowledge

The damper's job is very simple to explain - to keep the tyre in contact with the ground wherever and whenever possible...

Wheels & tyres - Bigger wheel fitment consideration

Predominantly 13-inchers, but 12s as well, the main thrust of the questions being 'what do I need to do?'

This subject is a regular visitor to the message board and 'Knowledge' section of Mini Magazine for whom I write - fitting bigger wheels. Predominantly 13-inchers, but 12s as well, the main thrust of the questions being 'what do I need to do?' along with 'which wheel arch extensions will I need?' The answer has always been somewhat 'clipped' purely because of the space availability issues both in the magazine and on the message board, so something a little more detailed was required. Although the Mini suspension was designed around the use of 10-inch wheels with cross-ply tyres, a quick dash through history reveals that fitment of these bigger wheel sizes isn't a recent, 'modern' application.

C-AJJ4029 Vented disc/Caliper conversion kit

For use when converting cars which already have hubs fitted that hold calipers except 997/998 Cooper which will also require larger Constant velocity joints and Timken bearings, If you have brake shoe front drum brakes a kit C-AJJ4029A is available which contains all parts required..

The contents of this kit ...

C-AJJ4023 4 POT ALLOY CALIPER CONVERSION KIT

These calipers are intended for use on 10”wheels with 7.5”diameter solid brake discs.

The kit contains:-

2 calipers, one right and one left hand. Please ensure that they are installed correctly with the bleed screws in the vertical position (i.e. at the top)
4 longer hub fixing bolts(53K1049)
4 bolt washers(21017Z
4 round spacers (AN1380) which go between hub and caliper where the fixing bolts locate. Bolts and spacers not required when fitting to vented discs
1 set of brake pad split pins (GBK1025) BUT NO BRAKE PADS.

Alex Comis in the Super Mighty Minis Championship at Donnington Park

The picturesque countryside of Derbyshire was the setting for rounds 5 and 6 of the Super Mighty Minis Championship at the epic Donington Park. With pole positi

Fitting Instructions for C-AJJ4021 Spacer Kit

This kit allows the Minispares Alloy 4 Pot Calipers ( C-AJJ4022 / C-AJJ4023 ) to be used with the vented discs from the Metro.

Contained in the C-AJJ4021 spacer kit are the following: 4 Spacers, 8 ‘O’ Rings, 8 Bolts, Pad Pins and Retaining Plates.

When using the vented brake kit with 10” wheels the Metro brake disc will need machining down from 8.4” to 7.5” and the fitment of Minispares drive flange ( NAM6450F )

C-8G8993 - Fitting Instructions - Carbon Metallic brake pads bedding in procedur...

New Brake Discs

Thoroughly clean the new discs with a solvent degreaser such as brake cleaner or cellulose thinners to prevent pad contamination, then follow the following procedure to bed the new brakes in.

1. Perform several light stops (‘snubs’) on the first lap using progressively higher pedal pressure and braking force from higher speeds.

Minilite Wheels

Mini Spares are proud to announce that we are now the sole distributors of genuine Minilite wheels in both 10" and 12" wheel sizes.
Available sizes are: 4.5" x 10" , 5.0" x 10", 6.0" x 10", 5.0" x 12"