6 replies to this topic

[087dave]

Hi all,
i have a 75 mini which i have changed drums to disc brakes for 12" wheels

i was thinking of changing from the single bean can to the later type servo brake set up
from a doner car
but i think the brake pedals are different
so can you remove the pedals in place without removing the pedal box
Thanks

[OfMini&Men]

Not really you've gotta take the whole pedal box out to do it

Why not just run a remote servo?

[tiger99]

You actually need a different pedal box and lots of other bits. See the Somerford Mini web site.

http://www.somerford...page=page&id=58

A remote servo misses the point completely, as it remains a single line system. I believe that dual line remote servos exist, but are expensive and were never used on Minis. You could use a servo in the front brakes line only, but you would need larger bore rear cylinders, and a PRV set at much lower pressuer than normal, to get proper balance under light braking, while avoiding locking. It can be done.

[Ethel]

You can fit different master cylinders, as they all have the pushrod in the centre, but it's not a good idea to change pedals.To connect to the pushrod centrally, they can only move the pivot shaft to achieve different lever ratios. The pre 76 pedal has a longer lever, the post 76 is shorter, for more mechanical advantage; it's also cranked further from the floor to allow for the extra travel.

The easiest option would be to fit a remote servo, though the horizontal servo cylinder has the biggest bore of them all so you shouldn't run out of reserve pedal travel. Though it would be sensible to check the bell crank doesn't alter the lever rates (i.e has equal length arms). I haven't tried that combination myself so couldn't say for sure. If you want dual circuit brakes you can plumb a remote servo into just the front circuit, the rear brake limiting valve would stop it contributing anything to the rear anyway.

[KernowCooper]

Remote servo would be a good conversion.

[087dave]

Thanks for the replies i have everthing to change over from a single line to dual servo
because i have a doner car
The car that i have the disc on is a automatic with a single line set up and want to put a dual system in

if i can take out the shaft in place that the padels mount on, should there be any problems putting on the servo type pedal?
Can you take the shaft out in place with out removing the pedal box?
Thanks

[Ethel]

You could if you took the heater out, just as fiddly in my view since you'll have at least the brake master off anyway. You could look up the part numbers for the shaft to see if it changed too; the pedal boxes are certainly different, as I tried to explain above.

Put late pedals into a pre '76 pedal box and they won't push squarely on the master cylinder pushrods.