Primary pressure regulation valve (page 4 of 5)

The engine braking valve allows the engine RPM to maintained relatively high, when it is necessary to have good engine braking (e.g. on steep descents or mountain roads).

When the selector lever is in position "D", the engine braking piston blocks the lubricating oil (17) and pressure is maintained at the engine braking valve. The pressure forces spring (13) to compress and pushes coil (14) towards the right.

1. "D" position
2. Sliding sensor
3. Engine braking lever
4. Engine braking piston
5. Pitot pressure
6. Modulation linkage
7. Safety valve
8. Transmission control valve
9. Transmission control cam
10. To primary pulley
11. Circuit pressure
12. Lubrication circuit valve
13. Spring
14. Coil
15. Engine braking actuation rod
16. Engine braking valve
17. Lubricating pressure
18. Pressure retaining valve