Brake experts please

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mjde, May 26, 4:53am
will this work!. Clutch master cylinder pushes slave cylinder that in turn pushes a dual circuit master cylinder. It's a room issue and I need to push a larger diameter master cylinder to feed bigger calipers. BTW it's not for road use. If not, why not!
Thanks

kazbanz, May 26, 4:55am
um why not cable or a push rodto big master!

jmma, May 26, 4:59am
Sounds OK in theory, but oh so much more to go wrong.
Is the push on a slave cyl. strong enough for heavy braking!

petermcg, May 26, 5:03am
I think it would depend on how much distance the slave cyl that the clutch master cyl is pushing,can do,, see it might not be enough force to push the brake master cyl in,,,,. and the other answer was cable,cables are best when they are pulling,, you need to push,,probably a mechanical system with levers and rods from your brake pedal or lever might be the only way

mjde, May 26, 5:07am
the last cable operated brakes i had was on a 37 for v8! never again! I know what you mean but really prefer to go down the hydraulic route as I would always wonder if the cable would hold up under extreme speed.

skin1235, May 26, 5:13am
fit a remote booster ( hunter type, most of the early rootes group including some chrysler) actuated by the existing system fit the twin behind the booster
or fit twin behind the booster already in the system
damn hard to work single calipers properly without vac or pressure assistance let alone twin pots

skin1235, May 26, 5:19am
most clutch masters and slaves are the same size core, ie no mechanical advantage, all you're doing is shifting it to a remote area not in alignment with the pedals
a brake master with 18mm bore works on 4 or 6 pots much larger, huge mechanical advantage but still works better with assisted system
brake pots typically need 400 psi to be effective, thats a lot of leg power, achieved with the mechanical advantage mentionedand as mentioned better with booster, also a lot more than you will get from a leg stroke even with a 10 to 1 advantage most pedal boxes give, some are as low as 5 to 1

mjde, May 26, 5:22am
Yes Skin I thought about that but the twin circuit cylinder that is on the hunter one would be too small to feed four pots on the front and possibly the same on the rear

mjde, May 26, 5:25am
I am using 5/8master to move the 11/16 slave to move the 1" master

skin1235, May 26, 5:25am
your tradeoff is the volume required to fully activate the pots against the volume the master can deliver in the length of it's stroke, and at the required pressure, you can alter the pedal pivot to give more stroke but it then requires more leg to achieve the same pressure, you are limited eventually by the max stroke anyway ( most masters only used 30 to 40% of their stroke)

skin1235, May 26, 5:27am
so for every 1 inch you move the 5/8 master the 11/16 will move approx 1/2 inch

snoopy221, May 26, 5:28am
It'll work-and end of the day late model disc[pad setup will prob require a booster master.
Gunna bea few damn calcs-and a few redrillins of pivot points to get the right

***FEEL***

Therin is the *BIG Kicker*

skin1235, May 26, 5:29am
yet for twin large pots you may well need a lot more then that, your 5/8 master will quickly run out of stroke ( and it will feel blardy peculiar to be almost on the floor before the brakes start working) - betcha you'll do a few panic stops before the head gets around that

skin1235, May 26, 5:31am
check out light truck systems, pressure over hyd, 2 to 5 tonne range

mjde, May 26, 5:32am
so good mechanical advantage then! how far typically would you expect the final 1" master to move at full brake effect!

skin1235, May 26, 5:33am
FEEL is going to be a huge learning curve , some serious hyd fluid shifting on small bore system is not going to be easy to accomodate

snoopy221, May 26, 5:35am
Tere ya go-all fools bein equal and alla dat.
was Tinkin ezakerrroey da sayme.
I.E. Jump inta a Hino-without air up-and try and use the clutch.
one ef dem small clucth units would rock in that situation.

skin1235, May 26, 5:39am
what uses a 1 inch master!, holden ss sport perhaps, and they'd use at least 1 1/2 inches of master shifting for their twin systems, from just on to locked up, ( and thats near 6 inches pedal travel)you'd need 4 at your 5/8 to get that, and even with a nominal 10:1 pedal thats going to be a lot of leg travel to get - up around your knee to fully extended - actually way beyond safe or comfortable and certainly well outside best pressure physicals

mjde, May 26, 5:41am
so with the light truck systems you're talking about, are they assisted with vacuum or air pressure! I can just see the reaction of any scrutineer. Hey boy take that compressor outa there! LoL

skin1235, May 26, 5:45am
light trucks commonly use 1 inch plus slaves on their rear shoes, 2 each side, some do the same fronts too, ( some have disk fronts), point being their systems are designed for high pressure ( typical brake line pressure light truck exceeds 400 psi) and more importantly high volume yet have not a lot more leg move than cars - humans cannot exert sufficeand even pressure through the complete arc of their leg swing, effective pressure is limited to a few inches at full extended

skin1235, May 26, 5:47am
they can be made to work with either, some are air assist already some are vac assist already, most LIGHT trucks do not use full air, ie they are assist over hyd

snoopy221, May 26, 5:49am
Outside the square maybe!
But a pedal box and 2 5/8's tin cans feeding 2 VH40/44 remote boosters could well give ya what ya want-frnt /rear bias vh 40/44 and pedal box bias!44 front 40 rear!

mjde, May 26, 7:10am
there we are going along great then you have to mention Pedal boxes and 2 boosters Cmon Snoopy this is a budget build and I wasn't keen on one of those $500 + pedal boxes Anyway thanks for all your responses so far and it looks like I may be barking up the wrong tree. I'll carry on looking at trying to find a booster to suit the system

supernova2, May 26, 7:31am
Sometimes van/ute systems can work when you have space issues.

kazbanz, May 26, 8:16am
mjde--awwe comeon mon ---why not spill with your plans--between us we might be able to come up with a solution.
Given what you are saying I thought why not a mechanical linkage of some sort