I'm doing a complete overhaul of my MK2's braking system. It's never been perfect. One of the rears was sticky, and recently, the booster wouldn't release. The fronts have been upgraded at some stage to a 3-piston ventilated setup, and the rear is standard.
If I'm going to all this trouble (and expense) I wanted to ask if anyone has converted to a dual system and what parts they used.

 

I'd spend the cash making the single circuit as sound as possible: steel braided hoses and good quality cunifer (copper-nickel) pipe. It will be as safe as a dual circuit with inferior pipework.

The easiest way to go (almost) dual circuit is probably to adopt the master cylinder and remote servo from the 420 and series 2 E-type. I've heard of people using the series XJ master cylinder-servo, but that will require modification to the pedal box to make everything fit.

 

Pete not sure about this but someone told me once that the 420 system was not a true dual circuit system. Not entirely sure what they meant but they referred to the master cylinder not being dual circuit.

 

Rob, That's right. It's dual hydraulic from the servo to the slaves. There's only a single hydraulic line from the master to the servo. However, the air valve is on the master so that might provide some sort of unprogressive braking if the hydraulic line fails. Those master cylinders are quite expensive compared with the ones in the Mk2 and S type.

 

That "dual" braking system in the 420 is only from the servo onwards as Peter says. And the master associated is a pain in the ar----e. It was also used with some notoriety on E types.
I have had 6 Mk2s and 5 Mk1s and the single circuit system is quite OK if it is well maintained.
Perhaps we have become "cotton wool" people associated with a lot of the later systems fitted to more modern cars with expectations of multiple backups etc. built in.
And there is aways the handbrake provided you have properly adjusted the pad clearances with a 4 thou feeler gauge as per the workshop manual

 

I fitted an X300 master cylinder and servo to one of my MK2's, really as an exercise to prove it could be done, I had to make a new mounting plate and weld it in and buy a brake pedal from a LHD car to move it to the correct position in my RHD MK2. The car was an auto and so I didn't have to worry about the clutch which would have made things more complicated.







I had to go back and cut the corner off when the engine went in to get the carbs to fit but this should give the general idea. I moved the battery under the offside rear wing and the wiper motor to above the brakes (changed to one off a mini).

 

Thanks for the responses.

I was hoping there would be a mix and match combination to do what I'm after.
It seems the remote booster and master cylinder is the stumbling block. Without both it doesn't seem worth the trouble as you're not really getting a redundant system.

Looks like I'll refurbish what I've got.

 

Homer, When you wrote under the offside rear wing, did that mean near the tail light (directly opposite the fuel pump) or above the axle?

Another option would be to put a modern servo in the place of the heater. On a RHD car, it would require a cross shaft to connect to the pedals. I think MG used one on the F and TF and Alfa on some RHD Alfettas. Since the old heater isn't the greatest device and many want a system with A/C, it might not be a sacrifice.

 

Sorry that's an error, it should have been the offside front wing at the rear of the headlights.