minidoido
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| posted on 30/8/07 at 02:39 PM |
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Classic Mini Brakes
Hi!
I have a 1974 mini and I recently changed the front brakes for the 4-spoke type from a Metro.
My main problem is that I bleed the brakes and it works fine for a day. After that I have to bleed the brakes again. I already changed the sealants in
the master cylinder, but I think that since it's the small one it doesn't have the volume of hydraulic fluid needed.
I don't know. Need help.
If I’m right what type of Master cylinder should I use?
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MikeR
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| posted on 30/8/07 at 03:10 PM |
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If you mean the four pot metro brakes i'd suggest getting a metro master cylinder.
It would also mean re-doing the brake lines as i think the 74 mini doesn't run full split circuit (trying to remember what my 73 mini did).
Whats the problem with the drum brakes anyway? They used to work perfectly well for me (once i'd figured out that when adjusting them, you need
to leave a little give otherwise you can't stop - boy did that garage door get close when testing!)
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iank
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| posted on 30/8/07 at 07:26 PM |
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If you have a single circuit brake cylinder you will need to upgrade. Details here:
http://www.minimania.com/web/SCatagory/BRAKES/DisplayType/Technical%20Information/DisplayID/609/ArticleV.cfm
If retaining single circuit ( ) you need a cooper S cylinder which probably costs the earth these days if you can find one. The dual circuit master
cylinder from a post 84 non servo mini is a safer and probably cheaper choice but will require a little more plumbing as MikeR points out.
Some other good info here http://www.minispares.com/Article.aspx?aid=121
but nothing about the master cylinder.
I'm a long way from my mini books until the weekend, but I'm sure there is something about this in 'how to modify your mini'
by David Vizard. I'll check when I get back home if no-one else pops up with a definitive answer.
Having been a near victim of mini drums (sailed across a crossroads with cars passing both sides as I went through!) I'd certainly agree with a
disk upgrade, but standard 7.5 or 8.4 disks would have been fine (or even a Fiesta conversion if you want a cheap way to upgrade and retain 10"
wheels).
--
Never argue with an idiot. They drag you down to their level, then beat you with experience.
Anonymous
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minidoido
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| posted on 30/8/07 at 09:32 PM |
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I forgot to say I've 1380cc installed, so after 2 "near death incidents", I decided to upgrade the brakes.
I will take a look at the threads. Thanks!
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hillbillyracer
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| posted on 30/8/07 at 09:52 PM |
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There used to be a set of braided flexi pipes available to convert the dual circuit Metro calipers into a single circuit type. Mabye still available
from someone like Minispares, they were nothing more than a single long pipe & a small link pipe that lopped round into the second port on the
caliper.
If the master cylinder is the original from 1974 then it'll be single circuit I think & as said you'll be better off with a later dual
circuit one, you could pipe the whole lot up like the Metro or keep it a bit simpler & get the conversion pipes.
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MikeRJ
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| posted on 30/8/07 at 11:43 PM |
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quote:
Originally posted by MikeR
Whats the problem with the drum brakes anyway? They used to work perfectly well for me (once i'd figured out that when adjusting them, you need
to leave a little give otherwise you can't stop - boy did that garage door get close when testing!)
You must have had the only decent set of drum brakes ever fitted to a mini! To be fair, if adjusted properly (an almost weekly task) they worked very
well at low speeds, or from one stop from higher speeds, but even an 850cc mini driven enthusiasticly could fade them into uselessness.
I'm a great beliver in drums on rear axles as I like a decent handbrake, but a front disk conversion for a tuned mini is a priority! Even
Cooper S disks are a bit marginal for a really quick mini.
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andyps
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| posted on 6/9/07 at 12:31 PM |
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My daughter has a '77 mini and it has a similar problem with the brakes (still with drums on though). I haven't sorted it yet but I
suspect it might be the brake light switch which is causing the problem as the lights only come on if the brake pedal is pressed really hard so I
suspect that there is some air gathering there. Got to change the switch some point soon to find out if this is the case.
The Cooper S master cylinder is a good idea if using 4 pot calipers due to its higher capacity and it actually sin't that much more expensive
than a standard one from Minispares.
Andy
An expert is someone who knows more and more about less and less
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Peteff
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| posted on 6/9/07 at 01:07 PM |
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You have to join the two sides of the caliper together with a link pipe, that was all that was needed in the olden days.
yours, Pete
I went into the RSPCA office the other day. It was so small you could hardly swing a cat in there.
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britishtrident
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| posted on 7/9/07 at 11:24 AM |
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quote:
Originally posted by MikeRJ
quote:
Originally posted by MikeR
Whats the problem with the drum brakes anyway? They used to work perfectly well for me (once i'd figured out that when adjusting them, you need
to leave a little give otherwise you can't stop - boy did that garage door get close when testing!)
You must have had the only decent set of drum brakes ever fitted to a mini! To be fair, if adjusted properly (an almost weekly task) they worked very
well at low speeds, or from one stop from higher speeds, but even an 850cc mini driven enthusiasticly could fade them into uselessness.
I'm a great beliver in drums on rear axles as I like a decent handbrake, but a front disk conversion for a tuned mini is a priority! Even
Cooper S disks are a bit marginal for a really quick mini.
Agree Mini with front drums were useless --- even worse I used to autotest one and can testify they didn't stop at all in reverse.
The later diagonal split dual circuit 1275GT (ie post Denovo/12" wheels) brakes were OK but used to pull to the side after the pads wore more
than 50%
Fitting discs to drum brake really Mini involves changing the master cylinder and bias valve setting.
However in this case I think the reported problem is down to either a tiny fluid leak or perhaps the conical spring in the Lockheed master cylinder
has failed.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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