For Coccinelle, Type 3, Karmann, trumpet box.

Combi T1 03/1955- again07/1967

Combi T2 rear right 08/1967- Kave07/1979

Residual pressure valve, 2 psi, for braking systems, METRICAL (10 x 1 mm) and is generally used to maintain constant driving pressure in the system, thus eliminating the excessive pedal stroke. The result is a more firm and reactive pedal. Most people install it on the rear brake line at the master cylinder level.