Brake lights slow to come on. Daimler SP250

[geeman237]

I have to press the brake pedal very firmly for the brake lights to come on with my Daimler SP250. The brake set up is, master cylinder to in-line residual pressure valve (see http://www.summitracing.com/parts/WIL-260-1874/ for details of the specific part), then onto a 4 way brake valve which also has a port for the brake light switch. The cars were originally built with an inline valve and this Wilwood one is a modern day replacement.

I have a new brake light switch to fit, but before I do, does anyone have any experience of this on their car and it might be something else? The brake pedal is firm and the car stops well (no servo fitted) but under normal driving and brake the brake lights don't come on. You really have to press down firmly for the lights to come on. Obviously this is a safety concern if some is coming up behind you!

Thanks in advance.

[1954etype]

The E type also works on a pressure switch which can be slow to react or fail. I solved it by fitting a mechanical swtich located near the pedal.

[832ark]

Must be the brakelight switch. Are they a known weakness?

[geeman237]

Thanks for the quick responses. I will go ahead and swap out the switch and see if that works. I do know other owners have had some problems in this area.
.....Oh, the joy of bleeding the brake system....

[TVR keith]

This four way valve, is the brake light switch pointing upwards?
Could it be that although you have obviously bled the brakes that there is a small air bubble right where the switch screws in, so you would have to compress the air before the switch operates, hence the excessive pedal pressure needed. Why not slacken off the switch with someone pushing the brake pedal to see if air comes out, might solve your problem

[larrylamb11]

You shouldn't need to bleed the brake system after just swapping the pressure switch. Fill the new one as best you can with fresh brake fluid (it will only take a couple of drops), undo and remove the old one. Brake fluid should start trickling out of the mounting hole. Then whack the new one in. Job done. Check the pedal feel after fitting and bleed if necessary, but generally its not necessary.

[geeman237]

Thanks for the extra tips. I will give them a go, hopefully at the weekend.