25 replies to this topic

[TopCatCustom]

Hi, as I'm working from a bare shell I'm wondering what is best for my brakes, it's going to be used for rallying but I dont want a twin MC adjustable fancy box, can I just use a single outlet MC and split the pipe for front and rear, and run an adjustable bias valve in the rear line? It will be in car so easy to get to, just not sure what my options are with master cylinders as I cant remember!

I'm running 4 pot alloy calipers up front and drums on rear by the way.

Thanks,
TC

[ado15]

If you want a single line master cylinder, there isn't a choice in terms of bore sizes. The specific Mini items currently available are 0.7" bore. You can get the GMC171 small reservoir one and the GMC172 Cooper 'S' large reservoir one. Both, however, have identical cylinders so provide the same fluid displacement/pressure.

[Ethel]

Strictly speaking, you can't use an adjustable valve inside a road car and it should have dual circuit brakes if it's post 1976.

[ado15]

The main reason for the larger 'S' cylinder is the capacity, 4 pots displace more fluid. So as your pads wear you need all the capacity you can get.

Quite true, but your brake fluid level should be checked regularly anyway..... of course, we all do this weekly as the handbooks tell us...... don't we???

Strictly speaking, you can't use an adjustable valve inside a road car and it should have dual circuit brakes if it's post 1976.

Is this a Construction & Use Act requirement?

Of course, not a problem if it isn't a road car.

Edited by ado15, 28 January 2011 - 05:36 PM.

[TopCatCustom]

I wouldn't mind a twin outlet one but I meant I don't want 2 cylinders, the only reason I wasn't sure if a twin outlet one would work was because I will be using an adjustable valve in the rear, but if they are cheaper and easier to get then it suits me!

[jamie@thefatgarage]

Strictly speaking, you can't use an adjustable valve inside a road car and it should have dual circuit brakes if it's post 1976.

Really? Every car I have has one (apart from my daily company thing). I presume most MOT testers are unaware of this rule... thank deity of you choice.

[mini-geek]

I have just been playing brakes on mine this winter..

I have a yellow tag MC with the pressure limiter on the X-member removed and adjustable bias valve plumbed into the rear..





Don't know how well it will work yet though! still not got my engine back in.

[Dan]

I presume most MOT testers are unaware of this rule...

No, it's just nothing to do with the MOT is all. It's still illegal. To get a bias pedal box through the IVA for example the adjustment has to be welded up, and not just a little spot of weld that you could chip off but complete seam welding of the nuts to the thread and the unused thread destroyed. It's considered acceptable to have an adjustable bias in a car that hasn't been IVA tested but just modified if the adjustment cannot be reached from the driver's seat, but I don't know if that's actually legal or if it's been tested in court.

[jamie@thefatgarage]

I presume most MOT testers are unaware of this rule...

No, it's just nothing to do with the MOT is all. It's still illegal. To get a bias pedal box through the IVA for example the adjustment has to be welded up, and not just a little spot of weld that you could chip off but complete seam welding of the nuts to the thread and the unused thread destroyed. It's considered acceptable to have an adjustable bias in a car that hasn't been IVA tested but just modified if the adjustment cannot be reached from the driver's seat, but I don't know if that's actually legal or if it's been tested in court.

That fine then.

"IVA's are make believe, like elves, gremlins and eskimos" Homer J Simpson.

[TopCatCustom]

I have just been playing brakes on mine this winter..

I have a yellow tag MC with the pressure limiter on the X-member removed and adjustable bias valve plumbed into the rear..





Don't know how well it will work yet though! still not got my engine back in.

So a twin outlet one will work fine with an adjustable rear line? If so is the MC you are using a standard mini one or are there still differences- and can I assume it will be cheaper than the big reservior cooper s type ones I seem to remember as being rather expensive?

[mini-geek]

if you look on Minispares website there's a tec article on there about it that'a what I based my setup off..

yes it's just a standard mini mini yellow tag MC usually on ebay for about a fiver

it can be expensive though as the regulator costs a bit...

[TopCatCustom]

Cool thanks, sounds like my brake set up is exactly the same as yours, alloy 4 pots and drums, will check it out.

[mini-geek]

this is the bias valve I bought, it's the best value for money and comes with the correct fittings. I would recommend it!

http://cgi.ebay.co.u...a4#ht_502wt_905

[TopCatCustom]

Ah from Caprisport! I beat the owner in his Camaro (IIRC) last year at Santa Pod in my blown V8 Mx5, by a good 2 seconds

[dfmini]

I am reading this topic with interest because i plan to do the same modifications.

But is it not suppose to be the top hole of the master cylinder linked to the rear brakes?