I want to use tin can master cylinders for my mini with 7.5 discs, but Im not sure what size or type are available or safe.

Also what size is best for the clutch since we are on the topic.

Thanks in advance.

You want a .70" bore for the brakes and a 0.750" for the clutch.
Cooper S Mk1 0.70" brake MC had a taller tank- not necessary provided you keep an eye on fluid level.
I have a nylon extender screwed onto mine, is easy to see the fluid level and adds a bit more capacity.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I recently learned that its not hard at all to remove and replace the tin tank if it needs to be repaired, swapped for a larger one or rotated on the cylinder for clearance.

Tim

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1951 Morris Commercial J Type Van
1955 BSA C11G
1961 Morris Mini Traveller
1969 Triumph TR6R
1977 Leyland Moke Californian

do you mean it's possible to take the tank off the cylinder/pushrod assembly?

Yes, they are just soldered on. I just had my original ones re-sleeved in stainless and the tanks had to come off to drill the ports. I did a deal with the re-sleeving guy where I took the tanks off and replaced them afterwards. It turned out to be pretty easy. I took the opportunity to swap one of the tanks for a better one off a spare.

I've also seen them with a big dent hammered into the side of them for clearance, when all that was needed was to unsolder it and turn it around.

Tim

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1951 Morris Commercial J Type Van
1955 BSA C11G
1961 Morris Mini Traveller
1969 Triumph TR6R
1977 Leyland Moke Californian

rotating the tank for clearance means you have the wrong type for the job,,, the brake one is different to the clutch one for clearance reasons

but as the good Doc said, i like running .7 for the brake & .75 for the clutch so however you can sort that part, i would

& i have plenty of 2nd hand tin-tank master cyls here if anyones keen

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

I always wondered how they redrilled the ports after resleeving!

Most of them drill though the tank and then solder a patch over it.

The guy that did mine says he puts a rivet in the hole and solders over it. I wasn't buying into that, I want them to look factory, not patched. Having looked at the drilling that's required, I'm amazed that they can do it blind. He did a lovely job of mine.



Yeah sure, but there are at least two different orientations of clutch master cylinder reservoir. I think the later cars with the twin circuit brakes needed a different one to the early cars, and if you only have the wrong type...



Likewise, sometimes the reservoir gets in the way on cars with engine conversions.

Tim

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1951 Morris Commercial J Type Van
1955 BSA C11G
1961 Morris Mini Traveller
1969 Triumph TR6R
1977 Leyland Moke Californian

yeah Timbo, i know,,,, i`m not getting upset at anyone who uses the wrong one,,, just saying there are the right options out there , & i have plenty of the early ones here if anyone needs them

& yes the later type "clutch" cyl is a twin "seal" type, as opposed to the early "single seal & cup" type... & yes , also different reservoir orientation too

i have the early pressed-tin caps here too if anyones interested??? very very hard to get these days, i only have a few so get in quick

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Forget me if im missing the point but I would just buy a brand new one

http://www.minispares.com/Product.aspx?ty=pb&pid=38303&title=

Cheers

I forgive you Brand new ones aren't the same as the old ones, which is important when you are trying to do the perfect restoration.

The old ones have a different shaped top to the cylinder (in fact there were two different early styles), the plating on the modern ones is too bright (or khaki depending on what you get) and their bore is smaller than the early ones.

On the left is a 1960 - early '61 and the later one on the right. The '59 had a separate threaded nut on top of the cylinder which can be removed to access the bore from both ends.



Matt, I'll send you a PM about metal caps. I'm not trying to be argumentative, just pointing out that if you want to rotate the reservoir its pretty easy.

Tim

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1951 Morris Commercial J Type Van
1955 BSA C11G
1961 Morris Mini Traveller
1969 Triumph TR6R
1977 Leyland Moke Californian