Hydraulic steering issues, air, leaking, valves??

[Xmtbiker]

Hello,

A problem began with my hydraulic steering system on a recent passage from San Carlos to Mazatlan, Mexico.

A brief overview of my hydraulic setup:
I have a cockpit wheel and a hydraulics pump for the autopilot both connected to a hydraulic ram pushing the quadrant on my rudder post. The whole system has a valve I can open to allow my to turn the steering with the emergency tiller and allows a bypass for the fluid.

The problem is:
The autopilot and to a lesser extent the wheel seem to be able to turn the rudder fine to stbd, however when trying to return to rudder to center or turn to port the rudder does not move for some time and then seems to "catch", even though both the wheel or pump have been turning to port. After a few hours of autopilot the hydraulic oil seems to expand and start coming out of the fill hole on the steering pedestal.

I do know that some of the joints in the system leak a few drops of oil on occasion, although this has never seemed to be a problem. Does this sound like a check valve issue? Could air in the lines cause this sort of thing and would a drain and bleed solve the issue perhaps?

Any suggestions would be great at getting good help in Mazatlan may be hard to find. And I prefer to do everything myself as I am a cheap cruiser.

Thanks!!!!

[paulajayne]

Looks like air - Ram seals seem to be the start point.

[Xmtbiker]

Yeah, should be able to get a closer look and tear down tomorrow. Would air cause the fluid in the system to expand and come out the top vent hole?

[paulajayne]

Air being compressible will get hot when worked, expands and could put the pressure high enough to cause the system to vent.

Most hydraulic system faults are either air related or leaks around seals.

On a dual action ram such as the steering one air is normally drawn in as the pressure decreases on the side not doing the pushing.

SeaStar Solutions

May help

[Xmtbiker]

Looks like I have an old model Wagner model n85 ram. As far as I can tell there are no bleed nipples, any ideas how to get the air out of a system like this?

http://www.helmsmansystems.com/downl...ual.pdf#page57

[Owe Hansson]

Make sure that the reservoir is full. Turn the wheel lock to lock. The air will usually work its way to the highest point. If not, hold the wheel hard to port or starboard while cracking the pressurized fitting at the ram. Of course the problem will reoccur unless you fix the leak


Sent from my iPhone using Cruisers Sailing Forum

[DeepFrz]

IMO it sounds like something in the system is binding causing the oil to heat and expand. It most probably would be the steering ram but could also be in the rudder bearings or even one of the pumps.

[Xmtbiker]

Owe Hanson- Do you mean crack the hydraulic fitting itself and let some fluid out? How to you keep more air from coming in without an actual bleed nipple?

DeepFrz- Hmm, that could be, I know the rudder is fine because it feels great with the emergency tiller. However there could be a problem with the autopilot pump, Raymarine type 1.

I removed the ram cylinder today and while there where no obvious leaks their may be a bypass allowing air in on one of the seals? I will try and take it to a hydraulic shop on Monday.

[Owe Hansson]

That's what I would do. If there is no bleed nipple I would just crack the fitting. As long as you're holding some weight on the wheel, oil will come out of the pressurized line and no air will get in. Just make sure that the reservoir is full so you don't suck air in from there. Be sure to fix the leaks you mentioned


Sent from my iPhone using Cruisers Sailing Forum

[Xmtbiker]

Thanks everyone for your help! I installed the Ram the other day after new seals were put in. So far so good. system bled fine by simply cracking the fitting a bit. Had to work the wheel back and forth a lot from end to end to release air at the reservoir. The wheel only spins 5.5 times now instead of 8! Sweet, must have had lots of air.

[Cheechako]

When you get a chance buy a barb fitting the size of your fill plug on the helm. put a clear plastic hose on it with a small funnel at the top. Fill with this and then work the system back and forth lock to lock until you see no bubbles coming up the tube.

[Xmtbiker]

Thanks Cheechako, I used that system while bleeding and it worked great. Not sure if it had been done in years!