Brake light switch

[Peter Lethbridge]

Can anyone recommend a reliable brake light switch for 1988 7. Thanks 

[Jonathan Kay]

There's a switch from Car Builder Solutions that is widely recommended. I don't know old a Seven it will fit but I haven't heard of any problems.

Jonathan

[rkeywood]

Possibly a hydraulic switch? '88 sounds a too early for a mechanical switch (my '89 is hydraulic)

[Peter Lethbridge]

Yes hydraulic,needs a lot of pressure to activate.Looking for a replacement 

[toldfield]

You might try here

https://kelvedonlotus.co.uk/product/hydraulic-brake-light-switch/

It appears to be the same as an Elan S3 switch.

 

tom

[Jonathan Kay]

Hydraulic brake switch:

Full search of the archives.

The thread is 1/8" NPT. The part number isn't  Lucas SMB 423, might be Lucas SWITCH2SH SPB401 900 09/01.

Caterham Parts out of stock: their ref 5161-B.

At this point I'd talk to Redline.

Jonathan

[Jonathan Kay]

"You might try here

https://kelvedonlotus.co.uk/product/hydraulic-brake-light-switch/

It appears to be the same as an Elan S3 switch."

Thanks. That's SKU: X036J6017Z.

Jonathan

[7 wonders of the world]

or convert to the later mechanical switch using the switch listed in #2

[rkeywood]

It's a standard 3/8" x 24 UNF parallel (same as brake fittings), 5 bar, NO switch as used on loads of old British Cars. The Caterham supply is/was an Intermotor 51610. The Lucas equivalent is SPB401. Both are widely available. The Kelvedon switch is their equivalent. I'd go for the Lucas.

Not sure how you'd convert an '88 pedal arrangement to a mechanical switch

[orangepeel61]

I can confirm that the hydraulic switch requires too much pressure to operate. 

I found I was able to bring the car to a complete stop without the brake lights coming on! Replacing the switch made no difference, in the end I fitted a secondary switch, a cheap micro switch from flebay and an angle bracket! 

In more recent times I have replaced the master cylinder, that made no difference either!

I'm convinced there's a lot of cars (not just Caterhams) out there with these hydraulic switches and the owners don't realise that they don't work!

[Peter Lethbridge]

Thanks everyone,ordered from Reline

[Nigel Riches]

The hydraulic switches are hopeless, replace it with a proper switch, leave the hydraulic thing to bung the hole. something like #10 is the way to go, I have fitted a similar arrangement with a plunger style switch, much more reliable and can be set to activate at various  pedal travel., to suit when you want the tailgater to go away. 

[aerobod - near CYYC]

It is also worth using a relay unless the switch is well designed to switch the full brake light current. The cheap switches fail quickly when passing 4A or so through a lightly brushed brake pedal (arcing a lot when the contacts are only lightly closed), whereas 30mA through the switch to a relay that can quickly activate the brake lights with minimal arcing increases switch life significantly.

[John Vine]

#13. Good point. I imagine an LED set-up (JAL, for example) will draw a much lower current.

JV

[7 wonders of the world]

biggest issue with the OE switch is the pedal smacks it once released and breaks the plastic pieces inside, partly cheap component, more down to poor adjustment of the switch.