I owned 3 of these classics in various states of repair and spent 14 years in the motor trade in the eighties and nineties. I became very familiar with the Austin Mini and have had probably every part of one lying either on the kitchen table or the kerbside!
Now these cars are fondly remembered and have rightly deserved their 'classic' status, particularly since their replacement with the BMW version.
I want to point out a few problem areas for first time buyers of these 'work a day cars' from my own experiences.
Don't let any of my points put you off buying one of these cheap to run and normally reliable cars, just use them as a guide for what to be aware of when viewing a potential purchase.
As the Mini stretches back to 1959 I can't possibly hope to cover every version, but as the car changed very little over the years, the following points are relevant throughout it's production.
Bodywork.Oh dear. Austin and later BL were like most other manufacturers when it came to rust proofing and seam sealing etc. They paid it little attention. Although the Mini is by no means one of the worst cars of the 60's,70's and 80's, they certainly weren't the best.
The body is a monocoque and so it's integrity is essential.
The front and rear suspension assemblies are mounted on subframes attached to the body on rubber mounts.
So if looking at a Mini, start under the sills.
First check the seam between inner and outer sill.These rot readily and easily.
Now move forward to the front floor pans, again these can rot easily.
While there check the mountings for the front subframe. These don't tend to rust but they do rot and can collapse. Their not difficult to replace, just awkward!
Move to the rear of the floor and sills and check where the rear subframe mounts to the
car. While at the rear start moving up the car now and check the boot floor. The battery is mounted in the boot, and it's not unheard of for batteries to drop out on to the road!
Another common rust trap at the rear is under the rear seat and in the side pockets where condensation can gather.
Now wander to the front and check the door hinge panels, again doors have been known to drop off.
The inner wings are not a general rust trap but like any inner wing they lead a hard life so check them.
Unusually the bottom of the A-frames at the windscreen corners can rust quite badly and repairs are difficult. It requires the windscreen removed and the repair panels need careful alignment. A tricky job.
While the bonnet is up, check where the outer wings meet the front panel. This is a classic water trap and rusts easily. These panels are cheap to buy and fairly easy to replace.
Apart from all the above the Mini will rust in the usual places such as door bottoms, bonnet edges, rear wing bottoms, rear valance and because of the shape and inbuilt water traps, the rear subframe itself.
As the entire frame needs replaced, (it cant be effectivley welded) putting this right is a pain and expensive and has been the reason for many a car to be scrapped.
Also the Mini had trims fitted over the external panel seams. The external seams meant the car was easier and quicker to weld together at the factory, however these trims trapped dirt and water making ideal rust traps.
Every panel is available for Minis these days, new or second hand. So repair costs are not too bad. The problem is the amount of labour involved and the costs if you can't do it yourself.
Engines and running gear.Minis were fitted with OHV engines from 850cc to 1300cc over the years. These are simple, rugged and reliable. Even when they are completely worn out with chain rattle, piston slap, worn big ends etc etc. They will keep going!
If you come across an engine that refuses to start easily or is very lumpy on start up. Walk away unless the body work is perfect. There are plenty more out there.
The gearbox is famously inside the sump. These are reliable and long lasting with few design faults. They will become a bit noisy over time and first gear will 'whine' but this is not unusual. Live with it!
The CV joints are a bit of a weak point and often need replaced, the tell tale sign being a knocking noise on full lock.
Replace these sooner rather than later as they can collapse when very worn.
Apart from the above the engines should give little trouble.
Suspension and steering.Again simple and rugged.
Front ball joints are a weak point but easily adjusted or replaced.
At the rear the 'knuckle joints' on the end of the rubber cones do wear and are tricky for the DIY mechanic to replace. A special compressor is required, but most garages are familiar with them and either have the tool or are able to cobble something up.
Brakes.Mini brakes? Well it has got some,they're not great, but they do work! Usually.
Although to be fair late models had discs on the front and are much better.
Again simple and cheap to fix. Don't worry too much about them when buying. Everything is easy to fix,replace or upgrade.
The Mini is fun to drive, fairly easy to fix, cheap to run and the sort of car that gets under your skin!
The above are just my own observations from years of driving, owning and supplying parts for these cars. I hope you find this helpful.