Volvo P1800 » Brake Pressure Switch

If you have a '67 or earlier Volvo it's a good idea to check the brake light function often. The most common failure is the hydraulic brake light switch. To test that the wiring is not the problem, pull the two wires from the switch and, with the key on, touch the tips of the two wires together.

Have a friend tell you whether the brake lights function. If the lights function while crossing the wires but not when you step on the pedal it's likely the switch has failed.

To replace the switch you'll need: One 7/8" wrench to remove the switch and a good set of Vise-Grips to keep the junction block from turning. If you proceed quickly, there should be no need to bleed the brake system.