401 brake light switch adjustment?
 

Is there any?

My brake lights only come on after severe pressure on the pedal. Crawling underneath I find a stiff wire hook going to 2 spring hooks, going to the switch. The switch works well by finger, but there is a tiny bit too much play it seems. I can't see the other end of the wire from below but assume it goes to the brake pedal.

To adjust it properly, what do i do? Is it from above with a floor & seat out job? Or a rather un Bristol bodge from underneath, a rather hit n miss attempt at shortening the wire hooks?

Brake light
 

Sounds like someone put in a mechanical generic switch often used on motorcycles.
Just shorten the wire or spring so it comes on sooner. You will do this from under the car whilst humming " Rule Britannia" !
Cheers,
Dorien

401 brake light possible alternative solution to problem
 

Why not track down a 406 (I think that it is this model) adapter which goes on the front end of the master cylinder and has a switch to replace the mechanical unit existing.
Regards
Mike Say

Thanks guys, having now worked out how to use the excellent original jack, and protected by a couple of large logs, I crawled underneath. I'm certain the switch is original, pretty much everything on this cars seems to be apart from having a re-wire & new interior trim etc. The switch looks ancient & is a perfect fit to the holes in its support plate (which is mirrored on the other side for LHD). I've pinched up the wire spring hook a little & fixed it, but I rather expect it to open up again & the fault come back. Had expected a better system on a Bristol, and indeed perhaps the change on later models is something to look into if it recurs. Thanks.