The strength required to steer a boat equipped with a hydraulic steering system is inversely proportional to the number of turns of the wheel lock-to-lock. The wheel turns are determined by the ratio between the cylinder volume, the pump displacement and the free movement of the steering device, e.g. the rudder. A large cylinder volume and small pump displacement results in a greater number of wheel turns and a small cylinder volume and a large pump displacement results in less number of wheel turns. Fewer wheel turns means quicker steering response but more effort needed and more wheel turns means slower steering response but less effort. The QL Hydraulic Steering Helm pumps are available in three different displacement sizes, i.e. 28 cc, 33 cc and 39 cc. Each of them are available for three different ways of mounting, i.e. front mount, rear mount and tilt mount. Three steering cylinders are available, all for rudder installations, and comprising volumes 116 cc, 168 cc and 215 cc respectively.
| Part no. | Pump | Displ./rev | No. of pistons | Relief valve setting | Max. wheel dia. | Weight |
| 3809971 | Front mount helm pump | 28 cc | 5 | 70 bar | 710 mm | 5 kg |
| 3809972 | Front mount helm pump | 33 cc | 7 | 70 bar | 710 mm | 5 kg |
| 3809973 | Front mount helm pump | 39 cc | 7 | 70 bar | 710 mm | 5 kg |
| 3809975 | Rear mount helm pump | 28 cc | 5 | 70 bar | 710 mm | 5 kg |
| 3809976 | Rear mount helm pump | 33 cc | 7 | 70 bar | 710 mm | 5 kg |
| 3809977 | Rear mount helm pump | 39 cc | 7 | 70 bar | 710 mm | 5 kg |
| 3809978 | Tilt mount helm pump a) | 28 cc | 5 | 70 bar | 508 mm | 5 kg |
| 3809979 | Tilt mount helm pump a) | 33 cc | 7 | 70 bar | 508 mm | 5 kg |
| 3809980 | Tilt mount helm pump a) | 39 cc | 7 | 70 bar | 508 mm | 5 kg |
| 3841280 | Tilt mechanism |
| a) Requires the tilt mechanism, which has to be ordered separately. |
