I'd be getting a 2nd opinion, this sounds over the top to me (just my uneducated opinion)

No it is not dangerous. This is how boosting was done from the factory.

The rear drums are not boosted and the hydraulic pressure is limited by the limiting valve (funny how that's its name). It does not take a lot of pedal effort to exceed the maximum hydraulic pressure that the rear brakes are allowed by that limiting valve. The rear drums can only take a little hydraulic pressure before they lock up, which is why the factory limits it. The only reason to brake the rear at all in a mini is to ensure that the rear does not try to swing around under hard braking.

The front discs require significantly more pedal effort than drums to get effective hydraulic pressure for braking. This is why there is a booster on the front. Having said that, the booster only reduces pedal effort and if it fails you can still brake effectively by pushing harder on the pedal. In fact, as with my own car, you don't even need the booster to have effective, i.e. safe, braking. The booster is all about reducing driver leg size needed for pressing the pedal, or in other words, driver comfort.

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

Nah it's cool I'll do it anyway. It's important to me that the brakes are well setup, so I'm willing to get it done. There is a place that does this test that is about 3 blocks from me so it won't be a hassle.

Maybe it's over the top and another engineer wouldn't need it done but it's no biggy. Also this way I'll find out in a controlled environment whether the proportioning is set up properly (front/rear bias).

I am in the ballpark of tripling the power output as compared to its original 998cc engine. So worth getting brakes right.

Edit: and yep re the post above I'm going to see what pedal feel and effort is like un boosted before I decide whether to run a booster. Or I'll install one if the braking test shows pedal effort required is outside of acceptable parameters.

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

Ok I get it thanks.

Morbo 28
If you use a tandem (dual) brake master cylinder you can not use imperial fittings
the master cylinder you made reference to. uses the original pipes that were fitted to the original dual master cylinder
the master cylinder with the yellow band is gmc227 , this is the one where they swapped the front and back outlets around
all dual brake master cylinders are METRIC , the dual brake proportioning valve mounted at the front of the car are all METRIC
pm me if you wish , imperial fittings will go into the metric hole, vey loosely , not advised

Mark

Aha okay that is good to know thanks. I guess I'll have to get a brake place to change over one end of the fittings.

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

Those are the requirements for NSW as I stated, I've no idea on SA

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Thanks for your help everyone, it sunk in eventually Does anyone know the thread pitch of the M10 and M12 outlets from this dual circuit MC? The brake place will make them up, just need to confirm this. (see below from my pm to MINImal Effort)

Hi MINImal effort. Your picture below has been really helpful to me setting up my brakes, thanks very much! Heaps easier to see what I need by looking at your well labelled pic

I'm getting some brake hoses made up. Do you know what the thread pitch it for the M10 and M12 outlets on that MC?

The brake shop has the following thread pitch options for M10: 1.0; 1.12; 1.5
And for the M12: 1.0; 1.25

Thanks, Simon (PS I'll put this on Mini chat too incase you're not around )

Subject: Switch to Dual Circuit brakes

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

Update - I found on a UK forum that they are 1.0 pitch, thanks.

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo