8 replies to this topic

[Oskifisk]

Hey TheMiniForum

 

I bought a classic mini, that has been standing still for 4 years now and i need to change the brakes, its a Mini 850 from 1977 and it has drum brakes all around. Should i convert every brake to disc or just the front once? Is it fine for long term just to convert the front once and change the back once to a new set af drums? 

Thanks 

 

Oskar

[sonikk4]

Hi Oskar and welcome to TMF.

 

Just change the front drums to discs. I would recommend the Minispares 7.5" conversion kit. Not cheap but it works well as this is exactly what i have fitted to mine.

You do not have to replace the driveshafts as the conversion kit will fit the original ones.

 

You will need to space the rear drums or buy spacered drums which again is what i have done.

 

You will need to fit a Cooper S master cylinder if you are going to use the standard system without a servo.

[cal844]

I bought the Huddersfield Mini Spares conversion kit (it came as an unbuilt kit, my mate kindly had to build the hubs and mount the drive flanges to the discs.

I had a spare pair of drive shafts with the cv joints already off, so fitted the new CV joints to these before stripping the car, from jacking the car up to sitting in it for the test drive took me 2 hours, including the usual time loss for seized parts.

My back drums already had spacers and longer studs fitted (I'd recommend changing the wheel bearings whilst the hubs are off, check the cylinders etc too)

My car has an original Black tag master cylinder and we also kept the drum size rear wheel cylinders, which gives a long pedal before the brakes kick in, but if I want to I can lock all 4 wheels (theres a time and place for that, not on a busy road)

Apologies for the ramblings but I hope this helps!

Cal

Edited by cal844, 01 October 2019 - 06:20 PM.

[Dannyboolahlah]

Depends what you want to use the car for.  Drum brakes are fine if you're just pottering about, and will stop you just as well as disks....once, then they get too hot.

If you plan to drive it hard then yes, its worth upgrading the fronts to disks.  The rears are perfectly fine on drums. There's no weight in the back of a Mini (especially under braking), the only advantage of using rear disks is to save weight.

[richmondclassicsnorthwales]

Yes - As above - totally recommend the 7.5 disc conversion for the fronts

 

Change the rear brake cylinders for new, change the lines if they are the old steel, and upgrade to Goodridge hoses.  That gives you a total new lower brake system system .

 

If the top bits need replacing - so be it          -  I would -        then your system is good for another 12 years. apart from the 3 year bleed all the system of brake fluid to get rid of the moisture brake  fluid attracts

 

Brake systems are a bone of contempt for me, I like to replace the lot in one go - the lot - then you know they are all good to go - only on a rebuild I must add - not replace one small bit and do the lot again, but as you may not know the full replacement history.

 

The pointer I add is - that brakes are designed to stop you - don,t let them kill you   Price over life is irreplaceable - you only have one life, no second go. 

[cal844]

Yes - As above - totally recommend the 7.5 disc conversion for the fronts

Change the rear brake cylinders for new, change the lines if they are the old steel, and upgrade to Goodridge hoses. That gives you a total new lower brake system system .

If the top bits need replacing - so be it - I would - then your system is good for another 12 years. apart from the 3 year bleed all the system of brake fluid to get rid of the moisture brake fluid attracts

Brake systems are a bone of contempt for me, I like to replace the lot in one go - the lot - then you know they are all good to go - only on a rebuild I must add - not replace one small bit and do the lot again, but as you may not know the full replacement history.

The pointer I add is - that brakes are designed to stop you - don,t let them kill you Price over life is irreplaceable - you only have one life, no second go.

I totally agree with this, especially the pointer paragraph, what I will add that yes some people might find how I worded the comment above, but the car passed the MOT again this year with a verbal to tighten on the handbrake(passed though lol)

[Ethel]

A 1977 Mini should have dual circuit brakes so no need to change the master cylinder. Though, if it's stood a few years that may make it necessary.

It would help to know if it's plumbed in with front and rear circuits or diagonally split before you start.

[richmondclassicsnorthwales]

A 1977 Mini should have dual circuit brakes so no need to change the master cylinder. Though, if it's stood a few years that may make it necessary.

It would help to know if it's plumbed in with front and rear circuits or diagonally split before you start.

 

A 42 year old Mini that does not need a new master ??

 

Front - rear - upside down system - diagonal - needs something -  you got to see where I am coming from with this one

 

I wouldn,t be happy with a 42 year old master - brake - no brake - tree - oops - bend - oops - bang !!

[Ethel]

Sorry if I didn't make that clear. It very likely will, but the type of cylinder is suitable.

I was also hinting at the next issue. If it's a diagonal split and the only readily available replacement is the yellow band master - with stepped bore.