ausmini :: View topic - Drum Brakes

Now, to "improve the performance" (reduce pedal pressure and travel) of the drums we can:
- Have drums machined or buy new ones - definitely buy new drums, machining drums oversize makes it that much harder to adjust them, and you lose half of the life of the shoes - they just don't have enough meat to reach out to the friction surface
- Keep them well adjusted - that's the key with drums, gotta keep them adjusted
- fit minifins (do these actually help??? better cooling I so less fade???) I have superfins on the back of my cooper, and I reckon it makes a real difference in motorkhanas, less weight means less inertia to stop, which means it's easier to pull them up.... but yeah, better cooling means less fade
- fit upgraded shoes? (Is there such a thing?) yes, there is such a thing, EBC etc. do them, I had some on the back of my van, but with disks on the front, I've no idea if they made any difference

Author:	albino235 [ Mon Feb 18, 2008 6:11 pm ]
Post subject:	Drum Brakes - The Options
Ok, I have done a search and I want to know how one would go about upgrading drum brakes, this does not include changing to disks as this thread is about making the most of what you have... reasons include keeping the car close to original eg. no flares. The way I see it drums are just as good as disks. If they can make the car skid (which they can) then they have enough stopping power to stop the car, sure it does take more pedal force with drums than with disks but in an emergency you get the same result (Is this thinking completely wrong?). Now, to "improve the performance" (reduce pedal pressure and travel) of the drums we can: - Have drums machined or buy new ones - Keep them well adjusted - fit minifins (do these actually help??? better cooling I so less fade???) - fit upgraded shoes? (Is there such a thing?) All ideas/thoughts and comments other than "just get disks" are welcome Thanks, Alex

Author:	Spaceboy [ Mon Feb 18, 2008 6:55 pm ]
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yeah you can get new compound fitted to your old shoes, very expensive but very effective. any brake place should be able to do that. fit a brake booster.

Author:	Morris 1100 [ Mon Feb 18, 2008 7:06 pm ]
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Make everything as good as you can, hoses, wheel cylinders, drums, shoes and adjust regularly. Make sure that all the shoes are assembled the right way. A booster will help but you lose feel which is a pain when you lock a wheel and want to back off a touch to unlock it. Front drums have two leading shoes which will make them prone to lock and hard to unlock, it is just a part of the design. The Yanks would drill the brake drums but that is frowned upon here. (it is just like drilling disks only with drums) I don't know if the real good lining materials are available anymore. When I was racing HQ Holdens we could not get the good linings anymore and had to use "Taxi" linings. Bendix was supposed to be making good material lately but I don't know if they would do them for a Mini.

Author:	Kennomini [ Mon Feb 18, 2008 7:12 pm ]
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I'd say fit a booster. Drilling them could be interesting and I'm pretty sure you can fit minifins all round.

Author:	Morris 1100 [ Mon Feb 18, 2008 7:15 pm ]
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You can fit Minifins all round but I doubt that you would notice the difference on the road. And the price of them these days is more than a set of disks.

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Drum Brakes - The Options https://www.ausmini.com/forums/viewtopic.php?f=2&t=39368	Page 1 of 2

Author:	albino235 [ Mon Feb 18, 2008 8:33 pm ]
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I am interested in this drilling of drums, has anyone here tried it? Also why is it frowned upon? Maybe a machine shop could put some rifling type grooves in the drums instead of holes to make it like slotted disks Also has anyone got any info on these possible uprated linings? I will have to try and do some searching for these... Are they likely to improve the brake fade or is it an overall improvement sort of thing? Cheers, Alex

Author:	sports850 [ Mon Feb 18, 2008 8:42 pm ]
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albino235 wrote: I am interested in this drilling of drums, has anyone here tried it? Also why is it frowned upon? It can cause the brake drums to explode when really hot/stressed which will leave you brakeless . I've seen mini's with 4 X 12 mm holes drilled in the face of the drum between the stud holes but further out towards the edge of the drums . No idea how effective it would be in cooling there though . I had always thought a couple of grooves across the friction area of the inside of the drum and a hole in the face of the drum would aid cooling them but I was never game to try it .

Author:	simon k [ Mon Feb 18, 2008 8:42 pm ]
Post subject:	Re: Drum Brakes - The Options
albino235 wrote: Now, to "improve the performance" (reduce pedal pressure and travel) of the drums we can: - Have drums machined or buy new ones - definitely buy new drums, machining drums oversize makes it that much harder to adjust them, and you lose half of the life of the shoes - they just don't have enough meat to reach out to the friction surface - Keep them well adjusted - that's the key with drums, gotta keep them adjusted - fit minifins (do these actually help??? better cooling I so less fade???) I have superfins on the back of my cooper, and I reckon it makes a real difference in motorkhanas, less weight means less inertia to stop, which means it's easier to pull them up.... but yeah, better cooling means less fade - fit upgraded shoes? (Is there such a thing?) yes, there is such a thing, EBC etc. do them, I had some on the back of my van, but with disks on the front, I've no idea if they made any difference I had a booster on drums, and I can't recall if it made a lot of difference, I think it did mean less maintenance with adjusting them.. I did a heap of front-end work on a clubman last year, and the brakes were utterly miserable - the front drums had been machined oversize, and while there was plenty of meat on the shoes, there was no adjustment left at all... when I stomped as hard as I could on the brakes, the back ones would just lock up, but nothing at the front. On top of that, there was (still is) a lot of play in the pedal, the master cylinder piston, and the pin that connects the two. It doesn't take a much wear in there to lose an inch of pedal travel, which equates to a fair amount of fluid that doesn't get pushed out into the wheel cylinders... when the bloke got the car back, he couldn't believe it, he thought it was like a new car Mini Deluxes and K's did the Armstrong 500 at Bathurst on drums, they're good enough to stop our little cars, just gotta keep them in top condition - like everything else

Author:	simon k [ Mon Feb 18, 2008 8:46 pm ]
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albino235 wrote: Also why is it frowned upon? weakens the drum - they're scared it'll break albino235 wrote: Maybe a machine shop could put some rifling type grooves in the drums instead of holes to make it like slotted disks the slots in a disk help scrape the crap off the pads, then flings it out and away from the rotor. No such effect possible with drums - any slots there would simply trap the dust and it couldn't get away, unless you managed some fancy spiral pattern... ?

Author:	1018cc [ Mon Feb 18, 2008 8:49 pm ]
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My mech told me that the really good stopping linings that used to wear well (and with a minimum of brake dust) had asbestos in them (I still run some on the back of my car). Of course we all know how availible asbestos is these days......... I don't reckon there has been any difference in stopping power since I now have (about 1yr ago) new pads in the front. The only noticable difference is that they do create alot more brake dust compared to the asbestos ones and they don't last as long. I have no idea what brand pads it now has in the front, I was told but have forgotten.

Author:	drmini in aust [ Mon Feb 18, 2008 9:00 pm ]
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Re machining drums out- when you do this, you do NOT uses standard shoes. The brake shop that machines the drums supplies rebonded shoes with (thicker) facings, which have been radius ground to suit the drum size. Standard drums are 7.0", the industry standard oversizes in Oz are +1/32" and +1/16" on diameter. As others have said we used to be able to get competition grade linings back when they contained asbestos. No idea if premium grades are available now.

Author:	matt van'74 [ Mon Feb 18, 2008 9:17 pm ]
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I agree that you can get drums to work as well as discs. But, Discs due to their increased surface area and their design dissipate the heat produced from your brakes more effectively. This means your chance of experiencing brake fade under road conditions is pretty limited. If you dont experience it with drums then this is probably irrelevant. Discs require no adjusting which in my opinion is a bonus. Drums need constant adjusting and the fronts are a little more tricky to adjust and also getting them to brake straight. It is just a feel thing though. After a couple of goes it will be easy. But it is just another thing to do on the car and after all driving it is why you own it. I run a set of 7.5 discs on one of my cars with no booster. The pedal is harder to push in comparison to drums but i have lost no feel and dont find it too hard to push. A booster would reduce it but I dont find it neccessary. I would not fit a booster to drums. A booster reduces pedal effort and with drums your pedal should not be hard to push at all. There is no problem with fitting one but in my opinion the decreased pedal effort will not really compensate for the loss of pedal feel that you will result. Drums have more parts to fail too. I have seen lots more burst or leaking wheel cylinders than leaking or failed caliper pistons. Also replacing pads is easy and only takes minutes. Whereas, replacing shoes can be a more long winded process and then you have to adjust them afterwards. To get a good set of brakes using drums I would: 1. Replace all hoses (Old hoses can "balloon" and give a spongy pedal) 2. Fit new wheel cylinders all round 3. Clean up and free up all adjusters 4. Machine or buy new drums. 5. Buy the correct shoes to suit ie) Std or OS 6. Adjust and bleed them correctly Inspect all the connections and dont forget to refit cooper washers. I find heating them up until red hot and cooling them rapidly makes them more malleuble (spelling). Discs are more expensive than overhauling your drum brake system if you are doing them yourself. If you have a spare $1500 lying around I would go for discs (remember you will probably have to change your rear wheel cylinders to 5/8 ). If not there is nothing wrong with drums but discs are more conveinent. Matt

Author:	brickworx [ Mon Feb 18, 2008 9:46 pm ]
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our mini 998 race car had drums all round... also had air scoops into the backing plate and drilled out to relieve the hot air out the back. Linings were rebonded with black tac material... not sure if still available. drums were standard. this car could do 6 laps of mallala where others could only do 3 before brake fade would set in.

Author:	albino235 [ Tue Feb 19, 2008 5:42 pm ]
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brickworx wrote: also had air scoops into the backing plate and drilled out to relieve the hot air out the back. That is very interesting... Do you have any pictures of these mods? Thanks, Alex

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Author:	Morris 1100 [ Tue Feb 19, 2008 5:53 pm ]
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albino235 wrote: I am interested in this drilling of drums, has anyone here tried it? Also why is it frowned upon? Maybe a machine shop could put some rifling type grooves in the drums instead of holes to make it like slotted disks http://www.chtopping.com/CustomRod4/ Or google "drilled drums"