How to Purge the Air From an Invisible Touch Hydraulic Steering

The Invisible Touch Power Steering system is a hydraulic steering system used on boats. Understanding how this design works is the secret to making it perform as it is intended. The unit comprises two separate closed hydraulic systems. The first has a high-pressure line from the pump to the helm and a low-pressure return line. The second is made of a pair of high-pressure lines running from the helm to the motors slave cylinder. Treating each of these as individual systems is paramount to properly bleeding the unit.

Instructions

1

Connect one hose to the inlet fitting on the hand pump and a second hose to the outlet fitting.

2

Connect the open end of the pumps outlet hose to one of the two barbed fittings on the helm. At this point it doesnt matter which fitting you choose.

3

Slide the capped hose fitting over the helms open barbed fitting. This takes care of where the new fluid will be going in to the unit.

4

Screw the barbed elbow fitting into the cap on the slave cylinder corresponding with the fitting you selected on the helm.

5

Slide the remaining hose onto the elbow fitting. This will be used as the return line.

6

Pour the power steering fluid into the reservoir, and insert the open end of the pumps inlet hose and the return hose into the reservoir.

7

Turn the hex-headed needle valve on the helm for the selected fitting a half a turn with a three-eighths-inch wrench to allow the fluid in.

8

Pump the fluid slowly through using the hand pump. Slow circulation and low pressure is needed to properly bleed this system.

9

Turn the boats steering wheel slowly from one side to the other to purge out any trapped air pockets.

10

Close the hex-headed needle valve on the helm once no air bubbles can be seen in any of the hoses. This side of the system has been successfully bled.

11

Exchange the inlet hose and the capped hose on the helm, and install the elbow fitting on the slave cylinders corresponding cap.

12

Repeat steps 7 through 10 to complete the bleeding of the Invisible Touch power steering system.