Bad Brake Switch?

Scooter · Post by **Scooter** » Sun Jan 14, 2007 5:36 pm

Now that I have LED tail lights. The brake lights on the back seem to flash and come on intermitaly, even when the truck is sitting still and the brake pedal is not moving. Bad brake switch is my guess? I looked at the schematic and found the wires. But where is the switch located? How do you replace it?

Any help would be apreciated.

Scooter

Jim LaGuardia · Post by **Jim LaGuardia** » Sun Jan 14, 2007 5:50 pm

The switch is on the master cylinder facing forward. Check for missing insulation or melting of the wires near the switch

The switch just threads into the master cylinder.

Scooter · Post by **Scooter** » Sun Jan 14, 2007 7:35 pm

thanks Jim, I'll give it a look see.

Scooter

Profpinz · Post by **Profpinz** » Sun Jan 14, 2007 8:10 pm

I was forever having problems with the hydraulic brake switch .... something I put down to the fact that I use silicon brake fluid ("maybe" it was migrating into the internal workings/contacts or something) as nobody else seemed to have anywhere near the failure's I did.

Replacement was a "b*^*&" given my Pinny is RHD, so I cured the problem by fitting a mechanical switch to the pedal box .... and all's been sweet ever since!

....so "if" anybody is using silicon fluid keep an eye on the standard switch.

Scooter · Post by **Scooter** » Mon Jan 22, 2007 8:45 pm

Well I have been trying to find the problem with the intermitant flash on the brake lights. It seem the brake switch has some votage going thru it even when not used. I has about 1.5 to 2 volts on the meter at times. My guess it should always read "0" when not used. I am thinking there is a contact going bad or something make contact when the brake is not pressed.

Is the brake switch wet or dry? Can it be removed without loosing the brake fluid? I want to replace it, but not sure how? thanks for the help.

Scooter

Jim LaGuardia · Post by **Jim LaGuardia** » Mon Jan 22, 2007 9:52 pm

Wet, you must bleed the masterafter installing the new switch.

Scooter · Post by **Scooter** » Tue Jan 23, 2007 5:47 am

thanks Jim. I am going to look at doing it.

Scooter

Jimm391730 · Post by **Jimm391730** » Tue Jan 23, 2007 11:45 pm

The switch will have ~24V between the two terminals when the brake is NOT depressed, when the switch is activated then you should see ZERO volts between its terminals.

Jim M.

Scooter · Post by **Scooter** » Wed Jan 24, 2007 5:35 am

Jim M.

That is completly opposite of what I measured with the meter. When I pushed the brake, that is when I got the 24V. I'll have to look at that again. :?: Thanks

Scooter