Hydro-Boost at Rest
With the Hydro-Boost at rest (engine on, brakes released) oil flows from the inlet (pump) port, across the number 3 land and out the gear port. In this position, steering pressure created by the steering gear and pump is isolated from the boost cavity by the spool valve. Lands 2 and 4 block this steering pressure avoiding activation of the unit. Any leakage goes directly back to the reservoir.
For disassembled photos, see
this post.
![hydroboostrest.jpg Hydro-Boost at Rest
With the Hydro-Boost at rest (engine on, brakes released) oil flows from the inlet (pump) port, across the number 3 land and out the gear port. In this position, steering pressure created by the steering gear and pump is isolated from the boost cavity by the spool valve. Lands 2 and 4 block this steering pressure avoiding activation of the unit. Any leakage goes directly back to the reservoir.
For disassembled photos, see [url=http://www.dieselplace.com/forum/showpost.php?p=4292833&postcount=6]this post[/url].](https://www.supermotors.net/getfile/280881/fullsize/hydroboostrest.jpg)