Stage 1 V8

Until Saturday afternoon when it ran out and left me driving through 2 town centres with no clutch at all....

Just in case you need it, the technique is to switch off the engine, select first gear and turn the key with a touch of throttle and you'll be driving along nicely. At 5-10mph smoothly back with the gearstick as you lift off the throttle and it'll snick silently into 2nd. Same again at 15mph and you're into 3rd.

For changing down, go into neutral, prod the throttle a bit to get the revs up and then put pressure on the gearstick and it'll go down into 2nd. If you're going a bit fast you'll need a bootful of revs or wait until you're going slower. Then when you need to stop knock it into neutral and keep the engine at a fast-ish idle to keep the battery charging nicely.

Anyway.... where's the leak likely to come from? There's a metal pipe from the master cylinder which goes into a rubber pipe across the top of the bellhousing and then into a metal pipe down to the gearbox and I assume the slave cylinder is inside the bellhousing? There's a bleed nipple next to where the pipe goes in.

All seems dry except for the last bit of pipe into the slave cylinder which is covered in grime but I can't see any drips and it would have gone right onto the exhaust pipe.

Where should I be looking? Is this the excuse I need to buy a brake pipe kit? Are the ends metric or imperial? My Stage 1 is 1982.

Thanks in advance!

Is the reservoir on the master cilinder empty?

99% sure it's either one of the clutch cilinders itself.
Change it for a new one. (Caution: Don't use shitty aftermarket ones, they are likely to start leaking again after a year or so)

Should be fine within a matter of time. The bleeding takes more time then changing the cilinder itself. The only bad thing that might happen is the pipe connector won't come out. Use excessive amounts of WD40
You can already start spraying that now..

Yes, the reservoir was empty although it's holding fluid fine at the moment.

Where's a good place to get new cylinders from? And how do I change the slave cylinder?

Slave cilinder replacement is done by undoing the 2 bolts and the pipe. Nothing more nothing less

I'd recommend to see the workshop manual. This tells you step by step how to do it. Even with pictures/drawings..

I order my parts just here in the Netherlands, but I guess ordering from craddocks etc will work out fine for you.

If you can't spot any leaking fluid on the slave cilinder.. Can you find a trail of fluid on the bulkhead underneath the master cilinder? You might need a spotlight to see it.
When it leaks excessively you will finally see it pouring thru the clutchpedal leaking on your shoes or in the footwell.

Let us know how you get on