Morris Minor Owners Club

Has anybody ever re-bored their master cylinder very slightly, in order to get rid of a slight indentation. I has a neighbour come and talk to me, saying he'd owned a few minors in his time and he said he once rebored his very slightly to make it smooth again, but not so much that the seals would no longer seal. Is this a wise money saver, or risky?

Risky.......... spend £50 and get a new one. It's not worth the hassle and constantly driving around worrying that you know it could fail at any time. A new one buys you piece of mind too!

Pattern ones are only £37ish plus VAT from Bull Motif..

The main problem with the master cylinder in the Morris Minor is that it is lying horizontally at the lowest point in the circuit. Normal brake fluid absorbs water which builds up in the master cylinder. Because the water is heavier than the brake fluid it sinks and causes localised rusting along the bottom of the master cylinder.
Whereas it might be possible to remove a little rust that was equally distributed around the insides of the master cylinder it is not really possibly to get rid of deep pitting in one place.
Fit a new one and consider using silicon brake fluid.

I see, yeah i came to my senses earlier on today and ordered one from bull motif, although i like the guys at charles ware, they can be a little dear for all their help. New ones on the way!

consider using silicon brake fluid

what kind of brake fluid is that? Is the normal DOT 4 brake fluid on a silicon base?

i think that regular stuff is generally known as synthetic, but mineral or silicone based is supposed to be better, and i think it needs replcing less often as it pulls in less moisture, but not intirely sure someone will know.

it will say on the tub whether it is silicon based or not.

It's very common here to have master & wheel cylinders resleeved in stainless steel - no more corrosion problems.
Is this not common in the UK?
50pounds seemed quite expensive compared to a resleeve.
Master cylinder sleeving here costs about $50.00 + seals ($30.00) which would make it around $80.00 or 32pounds (sorry, we don't have a pounds key here).

Is this not common in the UK?

Scott this only seems to be done on cars with spares problems and I believe its more expensive than your local prices, certainly more than a new one.

So there is some Minor parts cheaper here.
I feel better now.
Surely it would be better to go stainless sleeving if marginally dearer than a new cylinder - you'd come out in front in the long run. Or is this not the case.

So there is some Minor parts cheaper here.
I feel better now.

Well parts are cheaper over here but your local services appear cheaper, and I think that re-sleeving over here would be a lot more than a replacement cylinder as its done so rarely.

think that regular stuff is generally known as synthetic, but mineral or silicone based is supposed to be better,

Please please please people DONT put mineral fluids, oils or greases anywhere near the brakes!
Silicon brake fluid is 'silicon' based. Other brake fluids are brake fuid based..
Mineral oil (engine oil, gearbox oil, general purpose grease etc..) is a complete different kettle of fish and mixing them up will cause seal failure.

Silicon fluid is ok with most brakes systems (although it can be hard to bleed), but it is advisable to replace all seals with new ones as there are reports that old seals used previously in brake fluid for decades have swollen and failed when the fluid was converted to Silicon.

sorry!