Drum to Disc conversion

[gr8kornholio]

I searched for disc brake and didn't get a whole lot, so I'm going to throw this out there.  Converting from all Drum to 7.5 disc in front and drum in the rear.  I have seen that I need new rear drums to accommodate the added distance the front wheels will stick out when going from drum to disc.

Looking for experiences with different parts.  Minispares has original style parts and they have their genuine copies for about half the cost.  If they are similar in quality then I'll go with theirs since I'm not restoring an actual S car.  Thanks for any input on this.  I did read the thread on miss mini and her broken ball joints and checked out the beefed up hubs but ouch on the price. 

[John Gervais]

I was really jazzed about my new EBC 'S-type' rear drums, got 'em all painted nice and shiny and ready for my winter tire/brake change.  Well, it didn't go so well; the drums weren't exactly round - more like thump-thump-thump eggs.

I then ordered MiniSpares rear drums (GDB106) and they're fantastic.  During the summer months I use SuperFins.


Front brakes I can't help with, other than recommend one of the conversion kit from MiniSpares; I installed 8.4" when I changed from drums.  I have the MiniSpares 8.4" disks (21A2612), my second set in 17 years, with EBC Greenstuff pads - again, fantastic quality from MiniSpares.

There might be some information regarding the quality of the MiniSpares (commonly known as MSC) brand copies of the genuine AP calipers on one of the UK forums (fx. The Mini Forum).

[MPlayle]

I have done the disk brake conversion a couple of times.  Drums to 8.4" and drums to 7.5".

The past times I bought the kit and did all the assembly myself.  One time the kit was from MSC, the other it was from GB Car parts.

For my current Moke, I got new, fully assembled 7.5" disk brake sets from MiniSport for less than the kit (they did the assembly of the kit versus me - same parts - took advantage of a sale on the pre-assembled sets).

The rears can use either spacers (which come with the longer studs) or new drums with the built-in spacer (the longer studs are still required, but are extra when swapping to spacered drums).

I have used the kits with the after-market calipers and found them just as good as the "genuine" caliper kits.

[ADRay]

It's one of the best things I ever did for my Mini. It actually stops like a car should now.

I had the Seven Mini front disc conversion kit installed for me at the local mechanic, so I can't speak to the ease of the job. I also had new rear dum assemblies installed too.

the only thing I missed was ordering the correct rear drums - the ones with the 1" rear spacer. I went around for 2 seasons with a mismatched wheel track, which was visibly noticeable. I have since replaced them last summer with the correct ones.

[Willie_B]

This is all you need. From the gearbox out.

[gr8kornholio]

Thanks for all the information and that's a really cool picture.  I'll double check minisport for a complete assembly.  I've seen their hub assembly with the bearings and ball joints installed. 

Update: found it, under brake assemblies.  Odd it isn't also in the brake conversion area.  Outside of the bearings in the hubs and shimming the balljoints properly I'd think the rest of the assembly should be fairly simple.  Only reason I ponder this is they are using all S parts but I can save a couple hundred bucks if I use the minispares calipers and discs.

Huddersfield spares has a complete assembled kit, but their site doesn't exactly have a lot of explanation with the part listings.  Anyone had any experience with them.

One other thing I've noticed in the picture above and on minisport they include the stearing arms but the minispares kits do not.  Is this a required change or just a might as well while I'm in there thing?

[Willie_B]

In my photo that is all the parts I had bought or overhauled to do the change-over. I bought just the calipers from Mini Spares, the generic versions. I figured whie I was in there I would go over everything while it was apart. I used the steering arms that came off the old hubs.

[MPlayle]

In my past conversions, I reused the old steering arms - the kits did not come with arms.  I have not yet installed the assemblies from MiniSport (set aside for after the March drives) and do not remember right off if they had new steering arms.  I think they do.  I can check tomorrow and let you know (not likely to get back by my apartment today).

[jedduh01]

Don't forget Brake Hoses = time to replace  Disk hoses are a touch longer than Drum Hoses... And AGE! replace

Minisport / Minispares Alloy 4 Piston brake caliper sets are very nice. but be ready to clean calipers. Using Greenstuff dirty pads  will etch and discolor the anodizing of the calipers... (if you want clean calipers)

Standard AP or normal style 2 piston calipers are just fine too.

[gr8kornholio]

The minisport kits come with the arms but the minispares do not.  The previous owner replaced all of the components, except upgrading to disc.  Bummer that the lines are longer, cause it already has braided ones on it.

[Jimini II]

Some cars (not all) after being converted tend to lock up the rear brakes, the cure is to fit 5/8" wheel cylinders in place of (i believe) the 3/4" ones.

[MiniDave]

Isn't it he other way around? You need the larger ones in the rear to reduce the travel and pressure so they won't lock up?

[John Gervais]

I have the AKM2 parts catalogue, so I'll look it up - it's invaluable at times like this.

'S' brakes - 5/8" Bore (GWC1101 & GWC1101MS)

Fortunately, MSC has these pages available on their website:

Diagram, Descriptions and Part Numbers

[gr8kornholio]

That was going to be my next inquiry, is what all need modified on the rear.  I know I need spacers or the drums with the spacer or the finned S drums, but what all do I or should I change in the rear along with the new drum.

[John Gervais]

I've always studied the parts and assembly diagrams in order to find out which parts the factory originally put together with which other parts.

For example, when I converted to 8.4" disks in my front/rear split system and without servo assist, I looked up the appropriate diagrams and figured out what bits and pipe configuration I needed to maintain a harmonic and balanced system.  If you're not sure of which wheel cylinder you've currently got, then order new ones.  The same with the master cylinder - wouldn't help to have one which doesn't match the newly converted system, and if you've a diagonal split system, now's a good time to change it to something safer.

It takes a bit of back and forth on the website, but you'll be able to compile a parts list and go shopping from there.

You might need new rear wheel studs also -

[gr8kornholio]

That sounds like a good idea, I'll dig through my big orange manual and the websites to get a good idea of exactly what I have and all that's different with what I want. 

[ADRay]

I used 56mm rear wheel studs

[gr8kornholio]

Ok, any pad recommendations for the front 7.5" and the rears?  Or anything I should shy away from.  I haven't seen any evidence of the previous owner doing the rear brakes so if I'm getting new drums will probably do the rears also.  Looking for good quality parts for spirited but not extreme driving.

[MiniDave]

I'm running greenstuff pads.

Stay away from race pads, you don't need them and they're hard to get hot enough to work properly, plus they're noisy.

Minispares sells Mintex shoes and pads, which I think are good stuff.

[John Gervais]

Although I'm on 8.4" disks, I also recommend EBC GreenStuff pads.  They work very well from cold, relatively low dust (very fine powdery dust, easy to wipe off) and get only better as they warm up.  Be sure to break them in properly. 

I'm using MinTex GBS834AF shoes on the rear, both with stock winter GDB106 'S' drums and summer SUPERFINS. 

New springs are GBK1834.

Attached are .pdf documents that I made some years ago with bedding-in information, part numbers and pad-type info. 

I did, however, have a bad experience with the EBC rear drums - they weren't exactly round, so they're in their boxes gathering dust and taking up space until I figure out what to do with them.

[gr8kornholio]

Anyone have experience with so called speed bleeder valves?  The ones that allegedly have a little ball valve inside so you don't have to open and close with the press of the pedal. 

http://www.russellperformance.com/mc/speed-bleeders/index.shtml

http://www.stahlbus.com/products/en/bleeding-system/index.php

Or is there another alternative for bleeding brakes and clutch.  Thanks.

[MiniDave]

I just use a small bottle and tube, put enough brake fluid in the bottle to cover the end of the tube, open the bleed screw  and it won't draw air or fluid back thru it, then slowly cycle the brake pedal.

For a clutch I use the same setup....about three strokes of the clutch pedal and it's done!

I've never used the speed bleeders, but they seem like a good idea.....