While you don't NEED a kit ..it can be a useful way of getting all the bits.. Just make sure you compare what you need with what they include in the kit ..  Some places sell "disc brake" upgrade kits ..  The kit I bought included swivel joints which you may or may not need.... not sure whether bearings are common as well??

While you don't need new uprights you will need new drive flanges, and CVs (and pads) in addition to the bits noted above.... and maybe new flex hoses?.. I've always used the disc version and I think these are different from the drum types (different lengths). Drive shafts should be fine as I've done a few drum to disc conversions without any issues with drive shafts. New rear cylinders *might* be a good idea but I've been running a conversion where I only updated the front for many (20?) years... seems to work fine (although I do have a long wheelbase Mini).

I also disagree with the opinion regarding "road/race" pads... Fade is your big issue and you don't have to drive like a looney to have problems.  I find Greenstuffs (the S size) work "OK" from cold and only need a few applications to get up to full operating temp.  They're not race pads and you can overdrive them on the road (10Kms of downhill hairpins stretches them a bit ..but they come back reasonably quickly

Good luck, Ian

Big CV s also, at my first cold vintage I pulled out pits full blast down a 3000 ft. straight hit the brakes less than nothing! Great run off with long way to sand trap and tire wall good info to have. Always dragged brakes out of pits after that. Steve (CTR) 

All this talk of a conversion kit? you don't need a kit, all the Disc brake hubs are the same, all you need is a pair of disc's and calipers to get the bigger brakes? In an earlier post you spoke of machining the 7in disc's? this is not something I would ever do! they are thin enough already and skimming them will only get them hotter inducing more fade. So for the cost of a pair of disc's and calipers and rear wheel cylinders (Don't forget the rear cylinders or you'll be doing 180's in the wet!!) you will have good brakes that will stop and not fad.

One other comment, you stated you had bought road/race pads for the 998 set up? These will reduce fade with race type braking but not much else, they won't stop any better and may need warming up to operate with max efficiency not ideal for a road driven car. Good Std. type pads will be a better fit for your use. 
Use good quality brake fluid and a bleed the brakes, this will probably be the cheapest and best improvement to your brake system!!

To my knowledge there was only ever one axle set with a different spline count. It was a very early 850 set that had a different spline count on the CV end. It would be a small CV ( drum / 7 inch ) assembly and if removed the CV end has one less or one more spline. I have only ever held one in my hand in all these years. Steve (CTR)

A PO had done such a great job on rebuilding the front end and transmission that I wimped out on changing the discs. I did install EBC green pads as well as new shoes at the back. I am just waiting on a new clutch slave and pipe but will report back after I try it out (cautiously). I can get a new servo for $166 so will probably go ahead and do that anyway. I do appreciate all of the input.

If I can just ask again about the drive shafts. Am I wrong in thinking that the 998 Cooper had fewer splines on the shafts?

Steve

I'd have to agree with Chuck, I drove our 1000E around 100,000 miles with a single master and 7.5 s. I also raced and built vintage racers using 7.5 s with a single or dual master without booster. I currently run 7.5 s with a late LHD torque tube and boosted master all in one set up. Son Alex age 17 starts driving soon and I felt the best brakes would be just barely enough for a kid. Looking for a Cooper dip stick last night I think I saw a 7 to 7.5 kit in the UK for around 200 lbs. Much cheaper than front end wreck repair. Steve (CTR)  

Steve, reading what Ian usually posts leads me to believe that we would agree on most things Mini; however, the booster with 7.5 brakes is evidently one we don't. I much prefer the real feel of the brakes without the booster. I'd suggest if you go to 7.5s that you start without the booster (save some money); break in the new pads; then give the non-boostered brakes a good work out. If you still don't like the feel, add the booster.

If the 7's work keep them It sounds like pedal effort is the issue. You can get a simple power brake booster for not a lot of money from a hot rod supplier, and yes it will help with pedal effort.

I have a set of new in box 7 inch rotors, rebuilt calipers, spindles and pads looking for a project. Maybe one day :)

B

It looks like the 7" to 7.5" kit is getting more expensive as an option. I would also need to change the axles from the earlier 998 type to the newer "pot" type. At this point, I am leaning to more aggressive pads with servo
Steve

Ian - that is great input. I have the 998 style calipers/pads and am looking at the GBP102Ultimax pads - "road use with some racing". I agree with your comments on the booster. When one of the two boosters on my MGC failed, the bugger didn't want to stop at all!

I will be in the UK in a few weeks and find myself wondering about the weight of the 7.5" conversion kit to bring back...LOL. I suspect it would not fit in our carry on....

Steve

Hi Steve..its no big deal but seemed a waste to go off typing on a tangent..

The next step is to work out whether you have the 997 or 998 version..  998 pads are rectangular with two holes for the retaining pins where the 997 versions are more rounded on the sides with no retaining pin holes.  the earlier ones are about 30 odd % smaller than the 998 type.  I've been told that the 997 caliber can be modded to take the larger pad.  While a set of drums *might* be cheaper (depending on your access to second and parts) I would prefer the later pads which are much larger..

A booster would be worthwhile IMHO.  Many poo poo the idea and you'll get the usual comment "it won't make it stop any better".  Don't believe them.... While it might be true that in calibrated test the booster might not reduce the stopping distance it will make the car a lot nicer to drive.  The problem with the older discs is heat buildup and fade.  A booster would allow you to use a harder pad which delays the onset of fade..... if you can actually find any these days.  The booster can also be retained when you eventually upgrade to the S brakes.

I would carefully checking the prices though, upgrading the callipers (if necessary) and a booster may not be that
attractive when compared to the S upgrade... at least you don't have to buy the full conversion kit (all discs uprights are the same).

Cheers, Ian

I had NZ MK1 997 cooper from NZ.. K A2S4/12862 a few years ago.. sure mini mover will remember Tyrekicker and I towed to MME in Magog, Quebec in 03.. what a beauty.. but finding brakes pads were NO fun. and paid DEARLY for them.. later bc ps came across the BMHT  cert for it today.

Ian - sorry, I thought my post was clear. A previous owner replaced the original drum brakes with Cooper 7" discs. My car is relatively original and I want to retain the 10" wheels. I want to improve the braking without dropping $900 to do so.

As I see it, after comments received, my options in order of affordability are;

More effective modern disc pads and skimming the discs

Adding a servo to the above option

Sourcing a used set of twin leading shoe drum brakes

Replacing the lot with an upgrade kit to give me 7.7" Cooper S setup.

My existing setup is in excellent condition - they just take a LOT of pressure to stop the car. It would be great to get comments on the advantages of better pads as well as a recommendation.
Steve

If I could start with a bit of a quibble... It does help if we know what to comment on..  Do we read the second sentence to say that "one of the period upgrades .. that you fitted ..was .... Cooper 7in discs?? The reference to "pads" suggests yes.... If so, are they early 997 or later 998 types??   As I understand it (meaning I've not actually done it) the later type work (a bit) better... and the earlier type can be modded to take the later pads.

However, I would suggest that there really only is one option - S type discs.... or, if you're happy with 12/13" wheels, then 8.4" discs are OK.

If you already have discs then you can keep the uprights.  Otherwise you will need to add them to the discs, callipers/pads, drive flanges and CVs you need.  While a booster is optional with S discs I definitely prefer them.... especially when you move to harder (more fade resistant) pads.

Like Alex says, a good set of drum brakes can have better initial bite .. but you only need one hard stop..downhill from a decent speed to understand why the world has moved on to discs......  and there are a squillion different grades of pad from endurance race to city commuter.

My first Mini ...and my Daughter's ... had drum brakes and they're fine (unless you commute down the Stelvio .. but discs are just better.

Cheers, Ian

I had 998 brakes. I change them over to 7.5 discs when I got it done I went out Driving, driving hard and driving fast. I don't know what I was doing but I looked up and saw that all the traffic stopped in front of me. I literally stood on those brakes and the car came to a halt. I know that with those 998 breaks I would have been in his trunk. I figured that day those breaks paid for themselves .

I'm running 7.5" alloy 4-pots on my cars, but I still reckon that the initial bite of a properly adjusted twin leading shoe is better than a disc.

Just for the record: a few weeks ago I was asked to look over a late 80s / early 90s jap spec mini and I noticed it was the whole "retro conversion" with MKI tail lights, MKI grill, center binnacle etc etc but it also had(has) 10" wheels. I noticed it had the factory horizontal brake booster and then asked myself, "Huh?". It had twin leading drums fitted. Presumably this was the easy way to get 10" wheels, or maybe going disc to DRUMS is "the thing" in Japan.

Dunno.

Anyway, I took the car for a drive expecting it to be horrendous, with pull to left, right, pitter-pat, double pumping to get rear unadjusted shoes tightened up-- ALL the joys of drum brakes.

I was wrong.

They worked BEAUTIFULLY. They stopped VERY positively, in a straight line, and made me a believer: A Servo mounted to a drum braked car CAN indeed be an improvement.

I can't speak to spirited driving where the brakes get heated up and fade is induced. But for around town driving, a servo to some drum brakes really, dare I say, inspired some confidence! Pedal was high. Pedal had plenty of room for travel. 


All that said: Step 1 I'd say get some GOOD pads if you can. Someone like Porterfield or Hawk can make you custom pads. Just send them a set of old pads and they can make they for you using them as a pattern.

Barring that, and if you can swing it (under $1K), I'd do the 8.4-7.5 Disc Brake conversion kit. It is calipers, discs, drive flanges, pads. You'll need to add some large CV joints to it. MSSK013 or MSSK013MS which uses aftermarket calipers.

YMMV, Caveat Emptor, etc etc. 

As for the 7 inch disc depending on weather 997 or 998 the pads are different. I'm considering a set of 7 inch for my Moke with 850. Not sure I'd like them on anything faster or heavier. I have a number of twin leading shoe sets collected over the years a couple of sets include all new parts. I think they were installed then quickly removed and replaced with 7.5 disc.
 
If you have 7 s all you would require is the 7.5 drive flanges, 7.5 disc, 7.5 OE or after market calipers and the large CVs. The last three minis I have bought have had heavy front end damage. Each was running a metro 1275 and still wearing drum brakes up front. I recently tested my 7.5 disc with late servo to the limit. Six more inches of stopping distance and I would require body work. If I pick up a set of four pot calipers I will upgrade again, before turning it over to my 17 year old as a driver. Steve (CTR)

twin leading shoes stop as well as the S setup but tend to fade in repeated use, and sometimes can grab when hot. 


Forget about the brake booster, and spring for the S brakes. I think you can bolt the calipers to your existing uprights and swap the discs for 7 1/2"s. 


someone please verify this for us.