Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing brake light switch

These are kinds of fix I can live with, just about within my engineering limitations!

I just whipped the old one out of my brake line and replaced with a shiny new Intermotor 51610 in less than half an hour. Job done, big smiley face

It's a 2004 4/4 btw

Have you bled the brakes?

Um, no.

Yes, I know I perhaps should but in my defence I had read up on the change and once the old one was out I lay there with my finger over the hole until my BF had removed the washer from old and put it to the new, then I popped it back in.

I guess less than 2cc of fluid lost, possibly only one, and no sponginess in the system after 200 miles or so.

The problem lies with the hydraulic switch in the brake pipe. They often burn out as they carry too much current. I confirmed this by sawing one in half and the contacts were knackered.

I fixed it by putting a relay in the electrical circuit. Ideally the relay should have a diode in it and a small capacitor fitted across the hydraulic switch to eliminate internal sparking.

These are the details:

http://homepages.donobi.net/sufuelpumps/Other_Subjects/Electrical/General/Brake_Light_Relay.pdf

More recently it has occurred to me that a more elegant way of dealing with the problem would be to fit LED brake light bulbs as these take much less current.

John