That's why he is looking at extending the pushrod

Do the "late" ones have a different pedal shape?

Indigo is an engineer from memory so I don't think he has forgotten any mechanical wear points, and the indication is that it worked when originally installed. However, a few points that had been missed are the diameter of bundy tube and the length, both of which affect braking.

Yeah, miss read it. I thought he was saying the tin can had a longer rod, but what he was saying was that it will be longer when he extends it.

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Dalmeny

How are the two clutches linked to the pedal if I may ask?

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Fluid I'd guss, like they always have been.

Has the clutch ever worked properly? Are the brake lines the right size? Or is it just an issue with the amount of fluid the pedal is now expected to shift.

I ask as there's three master cylinders there. Two are obviously for the clutch pedal.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

what if you sleeved slaves down to smaller size, you'd probably need to calculate exact size. Sometihng like master cylinder stroke = 100cc @ 25mm travel to slave cylinder = 50cc @ 25mm travel? Not actual amounts/distances but you get the idea. Turn up pistons/liners on lathe.

I hope it's just a small issue. I kept adjusting my cable clutch because the damn thing was too heavy, turned out the cable was siezing in the sleeve. New cable, like a new car.

I'd be surprised if both clutches were working simultaneously, surely the rear one is slightly delayed due to the length of the lines. Lots of stories about people shortening the lines to neaten up an engine bay, not realising they're a specific length to allow for the proper fluid volume.

I'm sorry but i fail to see what the length of pipe has to the with the workings of clutch/brakes.

Master cylinder displaces x amount of fluid, fluid doesn't compress so slave cylinder receives x amount of fluid. The inbetween doesn't matter so long as there is no air. Granted flexible lines should be kept to a minimum. But what does fluid volume have to do with the price of eggs in china? And fluid doesn't compress for a time delay to the rear cylinder.

I've been wrong about things before but i'm pretty sure this isn't one of those times.

The Twini has two clutch master cylinders, one either side of the brake master cylinder.
I have extended the pedal box to the right, including the rod that the normal pedals rotate on.
The clutch pedal is now fixed to the rod which now rotates, and has an extra arm on it to activate the second cylinder. The brake pedal still pivots on this rod as per normal.

As for the length and diameter of the bundy tube. In summary, what goes in one end comes out the other. Thus the length and diameter of the tube is irrelevant unless you look at the friction of the fluid moving through the tube, which would be minimal due to the low velocity of the moving fluid. The other issue with the tube would be if it expanded under pressure, which I doubt. If it did then the tube would suffer from fatigue failure over time. This is not the case as there is a lot of 40 year old tube still in use out there.

The flexable line could be an issue as this may expand under the given pressure. As the rear line is longer than the front, I have replaced this with a braded unit which in theory expands less.

Do you get any rocking in the cross connect bar? It may cause one rod to push up a little further than the other.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Mick,
Have checked this out with a dial indicator - minimal deflection/ twisting between the two.
I also swapped the circutes around to check this. It made no differance.
Open to any other ideas.

Is it both clutches that seem not to be working properly?

Could it be something as simple as all the flywheels & backplates being machined back to true, but not the corresponding amount removed from the posts to compensate? So you need *heaps* of travel to get the clutch to work (straps aren't level on assembly).

Just guessing based on what seems to be happening on both after lots of new parts?

cheers

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project

I would use 2 master cylinders of the exact same sort, as the bypass port height in the late one might be different to the tin can one.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Err Doc, he's using two tin cyls for the clutch, placcie one for the brake

cheers,

Jacob

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'72 Clubman Van - 1022cc, 295 head, 731 cam - Daily Driver
'69 Morris 1100 S - Dinged by a bus, in shed under repair
'64 Morris 1100 - Early 1100, long term project