dual circuit master cylinder.

[bmcecosse]

Depends how much traffic is around you at the time.... I have spun a newly purchased Mini at high speed on a downhill - surrounded by traffic - without touching anything..... But it was a very near thing... The split system had been connected wrong way round with the main force going to the rear drums (one of which was soaked in brake fluid) and the lesser force to the front discs - one of which was seized. The car had an MOT that was one week old...
On the Minor - the handbrake should lock the wheels at 20/30 mph and is a pretty effective brake - IF it has been properly maintained, of course. It's even better if the 8" drums from a Wolseley 1500 are fitted!

[rayofleamington]

I wanted the dual circuit to limit the possibility of a total brake failure

Having had total brake failure a few times in my life (including once on a Minor coming down A MASSIVE HILL) I understand why it's important to avoid total brake failure, but am still VERY dubious about some of the claims on some split circuit m/c s

As for the Minor - knowing how to drive properly (engine braking) and eventually the handbrake saved the day on the hill.
The cause was a floppy brake pipe on rear axle that had no clips (not my car!! I'd only borrowed it!) and the vibration made it fracture.
The Fiesta that failed on me had a seal failure on the front caliper (caused by using copper grease), and the diagonal spilt breaking circuit did nothing, but fortunately it was not a dangerous scenario at the time, and handbrake worked well.

Many morals to many stories, but keep copper grease away from brake seals (if required, use a very small amount on brake pad slideways only!) and make sure that sufficient brake pipe clips are used!

[bmcecosse]

Hahaha - just last week while investigating slight brake 'pulling' I discovered the pipe to the rear nearside cylinder had slipped up on top of the axle - and had been battered FLAT by the exhaust...... New pipe made and fitted - and well secured to the side of the casing - and the exhaust re-hung to keep it further away from the axle - even on full bump (Trav has cut down bump stops).

[MinorMagic]

Hello All

The reason I did not split the braking system diagonally is very simple. Many owners fitting the system are using a booster( I think you call them servo's) and that makes it impossible to split the system in any other way than to simply split the system front to rear. The front brakes are the only set that is boosted. Boosting the rear also would cause the rear to lock up causing the car to be unpredictable under braking.

The master cylinder diameter is 13/16 which is exactly the same as the Lockheed Master cylinder currently available for the Morris Minor.

As for braking improvement, all I can say is that the pedal feel is really good and from comments I have received the pedal is much more progressive using this system over the standard system. This system was developed not to give you better brakes but safer brakes. Two braking systems are much better than one.

Added benefits are that the reservoir is engine bay mounted which will mean the brake fluid is checked and replaced more often. Brake fluid should be changed at least every 18 months. Getting down on your hands and knees, lifting up the carpet, spilling the fluid in the rail and not to mention how much dirt and grime enter the master cylinder every time the cap is removed would mean that the brake fluid on a standard system would rarely get replaced except at routine wheel cylinder changes.

Australian design rules have changed meaning that all newly modified cars have to have a dual circuit master cylinder fitted. This makes our roads just that little bit safer. My argument is why only modified cars? All cars should have this system regardless if it is my system or someone elses kit.

Darren

[simmitc]

You could open another can of worms about whether to boost front only or all round. I have always used a servo on all four wheels (front disc, rear drum) and it is perfectly balanced.

Incidnetly, Staffordshire Vehicle Components have a server that has a single feed in, but dual circuit out to allow a split. I don't know full details, but it's another option that some might like. There is still a single point of failure, but it's greatly reduced in length.

I have always thought that dual circuit diagonal split is the way to go, and so am very interested in the Australian experience. The only question now is: Do I need two servos