MOT failed. Left rear produces 1560N of braking force, right rear only 140N...should explain the ****ty vibrations I've been experiencing from the rear.

My question; after a new brake cylinder was fitted, we tried to bleed the system. The pedal took ages to go down with the open nipple and there was little to none fluid coming through. So it's etiher a mangled brake pipe restricting the flow or a knackered regulator. This being MY car, it's bound to be the second, expensive option.

Where do I locate this bugger, what does it look like, how much effort to fit/adjust/whatever?

Could be a blocked pipe

Only way to clear it is to keep bleeding it

Unless you've got a Rear Load Valve (on the rear axle) sometimes they can fail (uncommon)

Follow the brake like back from the cylinder, and see where you can bleed it from
If you can bleed it at the flexi - the flexi to cylinder pipe will need replacing

could be a huge airlock - which bleeding normally clears

Ziggy