Brake light switch on Astro Van

All the 3 brake lights stopped working on the Astro! So checked the fuese and the bulbs, all OK.

Haynes manual says there are 2 types of switch all linked on to the rear of the brake pedal.

Mine is not one of the 2! It has a vacuum pipe on the switch? Checked it out and it was working manually, so we had to readjust the switch. All in all quite easy ..... but not according to Haynes!