[Spridgets] Brake light switches - hydraulic and non-hydraulic types

[WeslakeMonza1330 at aol.com]

Hi list,
 
A bunch of spridgetly brake light switch questions:
 
The brake light switch on my 69 Sprite is hydraulic and if I gave the pedal 
 a good hard push works fine and the brake lines come on.  However, if I  
'dab' the brake pedal or press slowly the brake lights don't come on.
 
Is the reason for this poor switch action due to air being trapped right  
behind the switch sensor or is that unlikely/not possible with any air  being 
purged when I last bled the brakes, noting the brake pedal is good and  
firm. Or is the problem I'm experiencing simply due to the switch going bad  
and needs replacing.
 
I had decided to simply buy a new non-hydraulic/mechanical switch and since 
 I have both a later pedal box with provision for the mechanical switch and 
the  later 'hammer head' brake pedal to go with it.  However, having 
ordered a  switch last night but not looked at the pedal box until a moment ago I 
hadn't  realised that fitting the mechanical switch requires the pedal box 
to be  removed.
 
Other questions:
 
If I do fit the mechanical switch and want to remove the hydraulic switch  
does anyone know what thread it is?  I'm guessing it's BSPT and that I'll  
have to plug it with NPTF - but which BSPT and NPTF?
 
If I want to replace the 4 way union altogether I see I can use the 3H424  
later 3 way union from a later car which is also the same as the one fitted 
to  the rear axle (I have a spare).
 
Anyone done this and any comments on switch life or anything else  
whatsoever?
 
Thanks
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/spridgets/attachments/20150502/c3886748/attachment.html>