1986 Hynautics H50 steering. One question

[Porchhound]

I just replaced a lower helm steering pump and now I need to top off and bleed the system. The problem is, the manual shows two bleeder screws on the cylinder (one on each end) and mine only has one on one end. Anyone know if this one screw can bleed both port and starboard lines? It doesn't seem likely for obvious reasons.

Adding to the problem I don't know which line this one screw bleeds, and if I have to remove a line from the other end to bleed I don't know which one. Trial and error?

 

[Portage_Bay]

Does your system use a pressurized reservoir? Do you have the manual for your system? It will describe the bleeding procedure, a bit different that other systems due to the use of a pressurized reservoir. In my 1983 vintage system the bleed screws are not on the cylinder but on a block at or near the cylinder. According to the manual some of the sytems have the bleed screws at the reservoir.

 

[rslifkin]

Does your cylinder have 2 lines going to it or 4? If it's 4, then you probably won't need to use the bleeder screws on the cylinder at all. Just do the normal bleed process, then move the steering hard over to one side, open the relief valve back up and bleed again, then move to the other side and repeat one more time.

The 4 line cylinders have fluid flowing through them to the relief valve block from the helm pump (vs the relief valves being teed in before the cylinder if it's only got 2 lines). So they're easier to bleed.

 

[Porchhound]

It has the reservoir and there are two bleed screws at the bottom, but the manual also says to bleed the cylinder. With only one bleed screw that is confusing!

 

[mike66]

I just replaced my autopilot pump, which is lower than the lower helm pump. I just refilled from the upper helm, Turning the lower helm to the stops several times and repeating at the upper helm bled the system just fine. I didn't touch the cylinder. I got a few burps when I turned the rudder with the autopilot pump, but just kept filling at the upper helm until the level stabilized.

 

[Porchhound]

It has two lines coming in. I guess I could use the one bleed screw and crack one of the other two lines. Seems easer to just use both lines to purge and forget the bleed screw.

 

[Porchhound]

I don't have the option to fill from the upper or lower helm. No ports in either location. That would be easier!

 

[Gdavid]

It has the reservoir and there are two bleed screws at the bottom, but the manual also says to bleed the cylinder. With only one bleed screw that is confusing!

Assuming your reservoir is close to and mounted higher than the ram, any air will probably find its way back into the reservoir as long as you open both bleed screws at the bottom of the reservoir. Air has a way of working its way up to the highest helm pump, be sure to work the helm in bothe directions for 45 turns while the bleeder screws at the reservoir are open, this will ensure all air is chased down and into the reservoir.

 

[Porchhound]

Thanks. The reservoir is above the cylinder. I'll go that route and see if it is sufficient to purge it out.

 

[Gdavid]

Thanks. The reservoir is above the cylinder. I'll go that route and see if it is sufficient to purge it out.

It goes without saying but make sure your reservoir doesn't go empty during all of this or you will be starting all over and kicking yourself. On mine the clear view sights are too blurry and I have to open the fill cap to check.

 

[Portage_Bay]

I don't have the option to fill from the upper or lower helm. No ports in either location. That would be easier!

Ok, here's what I would do. I have no bleed valves on my ram.
- Fill and pressurize the reservoir per instructions in the manual
- Open the single bleed screw at your cylinder until you get a solid air free flow of oil. Lots of rags and absorbent pads at the ready.
- Maybe crack the connections at the ram looing for a solid air free flow. With no bleed valves on the ram that's what I had to do. But I was starting with a dry system after a full overhaul of all components and installing new lines.
- Check reservoir level and pressure
- Use the bleed valves at the reservoir and turn the wheel on the UPPER helm per instructions in the manual.
- Repeat with the lower helm.
- Follow the instruction in the manual to bleed the AP pump.

Resist the urge to start at your lower helm. Don't run the AP pump before the instructions indicate you should.

This really is a simple process and easily accomplished.

You'll know you've got all the air out when with the bleed valves, all of them are closed, and you turn the wheel hard over and get a hard stop. No spongy feeling.

It may help you to understand that in normal operation the helms and AP pump only "shuffle" the oil one way or the other to move the ram piston. My understanding of the bleed valves at the reservoir, or in my case a block near the ram, is than when open and you continuously turn the wheel one direction it allows the oil to cirulate driving the air out of that line.

There is a statement in my manual that I can go straigh to the step of opening the bleed valves, in your case at the reservoir, and cranking the wheel. You will eventually clear the air but it will take longer. If your lines from lower helm and AP pump are still full of oil that may work well for you. There wouldn't be air in the lines "after" the lower helm and AP pump.

 

[Porchhound]

My sight glass is is almost opaque. I have to remove pump handle and use a dip stick I made.

 

[smitty477]

I don't have the option to fill from the upper or lower helm. No ports in either location. That would be easier!

Use this link - please note there is a sperate detailed link at the bottom to follow for bleeding the system.
Hydraulic Helm Rebuild