Hi

Does anyone know where I can buy a switch ( pressure sensor probably) that goes into a brake line to trip a brake light on and off

Try this thread

http://www.locostbuilders.co.uk/viewthread.php?tid=10508

Mac#1 sell em

http://www.mac1motorsports.co.uk/

Jason

Thanks

Talked to the guy in Mac 1 very helpful.

justo,
just a little tip (and this is imo and experience) when deciding where to fit your brake pressure switch, mount it horizontally, not vertically, therefore not allowing air to get trapped at the switch, which would cause you to have to put more pressure on pedal to operate lights (may not even work), note this has happened to me.

Is it ok if we all take note of that ? I'll be fitting mine soon i hope and had'nt thought of that little gem

Many thanks
Jason

If you use a hydraulic operated brake light switch, you might get away with putting it only the front circuit (as per old construction & use law) but I suspect you need two wired in parrallel one on each circuit .
Personally I an using a mechanical operated pull switch.

Our's is hydraulic switched and we've just charged the system. However, I understand the point regarding the airtrap. Now can I run this by you - if the switch triggers at 3MBar (typical pressure) what pressure will the airtrap be in the pressure sender? 3MBar... so unless there is a lot of air (and there shouldn't be) it will still fire. We had excess air in the calipers before we finished removing all air but the switch still fired... and the brake lights triggered. Could it be different pressure senders?

We mounted our sender:



there!

and got this:



Sorted!

[Edited on 12-3-04 by Hellfire]

my pressure switch looks the same as yours, i dont know what pressure is required to operate the switch all i know is that my switch only came on with my foot hard down on the pedal, then we held the pedal down while loosening the pressure switch to release any trapped air, then it all worked without any problem,with only a small amount of pedal pressure.
air at the calipers is very different to air at the switch, the air is compressed, if compressed at the calipers it will still operate the switch, but air at the switch may not operate the switch.
i'm not saying it is wrong to fit the switch vertically, just saying you are less likely to have any problems if mounted horizontally.the choice is down to the individual, i know that most people would like to build there cars right the first time with out any questioon marks!

[Edited on 13/3/04 by elitewiring]

[Edited on 13/3/04 by elitewiring]

Mines working fine,must admit i never gave the air lock at switch a thought.
Rescued attachment stop switch.jpg

yes, im sure yours does work ok, it is mounted horizontally, so there is unlikely to be an air trap.

As long as the system is bled so pedal is solid the switch will work -- pressure switches work equally well in gas or liquid.

Just to point out that according to the constructionand use regs brake light switch must operate any brake that works on the FRONT wheels --- putting a hydraulic type switch in the rear circuit of a fore/aft split system dosn't meet this requirement.

Likewise if anybody uses a diagonal split system either 2 hydraulic switches are required or a mechanical pedal operated switch.

In the highly unlikely event of anybody building a Locost with a handbrake operating on the front wheels this would have to operate the brake lights also just as it did on old Commer/Dodge PB vans.

[Edited on 20/3/04 by britishtrident]

is this screw you have used a self tapper? Just wondering how to do my p clips... Thanks!


Image deleted by owner

Yes joel,its a self tapper

I like to use self tappers instead of rivets as sometimes you need to add another P-clip or use hole for an earth.

cheers bob, looks like an easy solution to me!