Midas Cars Forum - www.midascarsforum.com

Ok here's the problem:

My Mk1 was based on what appeared to have once been a 60s Cooper S judging by the previous engine number (not with car of course...) and the fact it was previously fitted with a twin bolt subframe. It also had the single-circuit brakes & master cylinder of a Cooper S.

What I need to know is this: What do I need to convert it to Dual-circuit? You will need to be specific as all the cars I have dealt with in the past had everything fitted. Part numbers would be useful.

I am assuming that I need the right type of master cylinder (I am not interested in having a servo), then the proportioning valve which mounts onto the front bulkhead and a splitter at the rear of the car. However, which ones am I looking for???

Or should I just ditch this idea and stick with single-circuit? Both the single-circuit MCs I have need rebuilds - so either way will cause headaches.

PS For info the brakes will be standard 8.4" discs & callipers with spacer drums on the rear. I have a set of brake pipes ready to bend up still in their packaging which came with the car.

I'm biased (geddit?) towards using twin cylinders on a balance bar. You can make this like I did or buy the KAD kit that's intended for Minis. The master cylinders are easily available (Series Landrover) and you can lose the proportioning valve so the rear brakes will actually be doing something.

http://www.kentautodevelopments.com/shop/product/kad-adjustable-bias-pedal-box

I've got a .625" cylinder for the front and a .700" cylinder on the rear.

Lovely idea Rich but I am on a budget and that is beyond it!!

MrBounce wrote:Lovely idea Rich but I am on a budget and that is beyond it!!

Mine too, which is why I took the other option and made my own.

Sadly I don't have the skills to make one of those. I can't weld and don't have the necessary equipment. Will have to stick to the original plan I'm afraid...

MrBounce wrote:Sadly I don't have the skills to make one of those. I can't weld and don't have the necessary equipment. Will have to stick to the original plan I'm afraid...

Welding is just frying metal. I was fed up going to a metal shop everytime for my welding jobs. So I bought a good quality secondhand MIG welder with large CO2 bottle (these are exchange bottles) and it has been a joy to work with. It took me a few days of getting the hang of it and still have trouble seeing where I am with the torch. But any excessive weld is easily ground off. The first things I welded broke again, so turned up the power and the metal just fused. Eventually I was confident enough to weld my subframe spring bushings in. It's now one of my treasured workshop tools and highly recommended. Just don't make the mistake of buying a cheap electric arc welder. These things are rubbish.

Guys I love the idea of teaching myself to weld and fabricate but this is not something that my wallet can handle at the moment as I don't have that sort of money to spare.

Is it worth changing to dual circuit of not?

MrBounce wrote:Guys I love the idea of teaching myself to weld and fabricate but this is not something that my wallet can handle at the moment as I don't have that sort of money to spare.

Is it worth changing to dual circuit of not?

Only from a safety point of view, whatever you do I'd still suggest getting rid of the limiting valve and fitting an adjustable one (about £35). You can do this with either a single or dual circuit system.

I agree with Hans about buying a welder, I also got fed up carting bits of metal round various workshops, being charged each time.
Bought mine new from Machine Mart many years ago, prob should've bought more expensive, but it has stood the test of time and saved £££ in the long run.
Mind you, I had to buy a cheap pair of reading glasses as I go long sighted in my advancing years, could hardly see the metal I was welding till I bought them.

Stick with what you've got, has anyone ever had a second circuit fail on them? So why complicate matters with a dual circuit? Brakes give you loads of warning when they start to pack in, I know that you are on a budget but my best brakes purchase was a Gunson Easy Bleed kit, this gets rid of all trapped air. I would also agree that you need a bias adjuster set up correctly,as well as the master cylinder kit. Oh dear this is starting to get expensive isn't it, however you could cheer yourself up by phoning a Porche dealer and asking them what all this would cost on a classic 911.

Incidently has anyone ever used residual pressure valves on a Midas, if so what do you think about them? No I had never heard of them until I saw them in the Car Builder Solutions catalogue recently.

Regards Mark