Sorry- don't have a manual but I've worked on several of these- there are gears inside the timing case cover driving the hyd & P/S pumps, etc. Your symptoms indicate a suction of air into the intake side of the hyd pump- usually caused by either a leak in the hose which feeds the pump or the pump itself.

Make sure all the fittings are tight (& hose clamps) on the suction side- don't make the mistake of thinking that all's good on the suction side because it's not leaking hyd fluid- air will leak in where oil can't leak out. This will be the hyd pump on the carb side of the engine.

If all's tight & you're still pulling in air- then the hyd pump is faulty.