I have the tech manual for the 830, 930, 1030, 1130 and 1630 (think these are all German built) and it has a troubleshooting section. May be of help.
For "Fails to Rise or Rises too slowly":
1. No pressure in system - chek hydraulic pump
2. Discharge valve stuck open - Turn in rate of drop screw compeltely. If arm rises, check valve for froeign particles. Check o-rings and back-up rings of valve plug for proper condition.
3. Return spring of valve operating lever unhooked or weak. - Remove plug on right side or rockshaft housing and watch valve linkage. If linkage moaves with the engine shut off, spring will be unhooked or damaged. Hook in spring or replace.
4. O-ring of rockshaft damaged or worn - replace o-ring and back-up ring.
5. Clutch petal depressed. Release clutch pedal so transmission oil pump can operate again.
6. Low pump output - check and adjust hydraulic pump.
7. Load control arm negative stop screw improperly adjusted.
8. Cam follower adjusting screw improperly adjusted (improper reaction inload control)
9. Rockshaft flow control valve improperly adjusted.
10. Transmission oil filter contaminated or restricted.
For "Fails to Rise or Rises too slowly":
1. No pressure in system - chek hydraulic pump
2. Discharge valve stuck open - Turn in rate of drop screw compeltely. If arm rises, check valve for froeign particles. Check o-rings and back-up rings of valve plug for proper condition.
3. Return spring of valve operating lever unhooked or weak. - Remove plug on right side or rockshaft housing and watch valve linkage. If linkage moaves with the engine shut off, spring will be unhooked or damaged. Hook in spring or replace.
4. O-ring of rockshaft damaged or worn - replace o-ring and back-up ring.
5. Clutch petal depressed. Release clutch pedal so transmission oil pump can operate again.
6. Low pump output - check and adjust hydraulic pump.
7. Load control arm negative stop screw improperly adjusted.
8. Cam follower adjusting screw improperly adjusted (improper reaction inload control)
9. Rockshaft flow control valve improperly adjusted.
10. Transmission oil filter contaminated or restricted.