Brake switch woes

Pete's been running for 4 years now and I'm putting in the fourth brake switch. It is solid mounted to the frame rail with rubber isolation. What am I doing wrong?

 

Maybe time to switch brands?

RockAuto shows six different brands: Omix, Delco, Airtex, BWD/Neihoff, and a couple I don't recognize. I'd likely pick Delco 1st, then Airtex.

 

NAPA/Echlin. Echlin is good stuff.

 

Echlin is the one I'm replacing now, Delco was before that, Niehoff before that. I'm losing faith.

 

Have you ever changed the brake fluid? Maybe there's something in your fluid (solvent? particles?) that's attacking the switches.

 

It was completely changed out (I use a jet pump type bleeder) before our trip to Idaho last year. I change it pretty much annually.

 

I just bought a painless brand one.. said it was made in the USA on the package.

 

I get about 2 years out of a switch.
There was a thread on one of the WWII sites where a guy installed a lever actuated switch from a Chevy pickup on the master cylinder floor cover plate of his jeep. It was a slick idea.