Autopilot/Steering System Component Identification

[hobbystuff]

I stripped out the original "Benmar" autopilot and installed a new autopilot system into our trawler 7 years ago. At the time the old Benmar autopilot pump was working fine so we just continued using it.

Well, it is now getting a little tired and the pump has some leaking. I am going to replace the pump with a new one.

Can anyone identify the grey component in the lines between the pump and the steering system? Is that some kind of a check valve?

Not sure if I should remove or leave in place - my gut says to leave it.

 

[ksanders]

Interesting...

I think you are on the money... The only logical thing it could be is a check valve

 

[twistedtree]

I believe it's a lock valve. It only allows return flow on one side when there is outflow on the other side, and vice versa. It's there to prevent steering from the helm pump from just pushing oil through the AP pump rather than moving the steering rams. So it "locks" flow to/from the pump unless it's initiated by the pump. It's built into modern pumps.

 

[O C Diver]

Could also be a bypass valve. Hynautic uses a similar system that bypasses excess pressure / volume. Visualize the steer cylinder at the end of its travel and you or the autopilot is still trying to move the cylinder further. The valve bypasses the fluid to the opposite line to prevent damage to the cylinder and possibly copper lines.

Ted

 

[twistedtree]

Could also be a bypass valve. Hynautic uses a similar system that bypasses excess pressure / volume. Visualize the steer cylinder at the end of its travel and you or the autopilot is still trying to move the cylinder further. The valve bypasses the fluid to the opposite line to prevent damage to the cylinder and possibly copper lines.

Ted

Yes, that's possible too. A close look will probably reveal numbering that will identify the part.

 

[sean9c]

It looks like what Kobelt calls a Safety and Bypass valve. It prevents shocks and over pressure by bleeding fluid into the other line once a certain pressure is met. Leave it in.

 

[twistedtree]

It looks like what Kobelt calls a Safety and Bypass valve. It prevents shocks and over pressure by bleeding fluid into the other line once a certain pressure is met. Leave it in.

Leaving it is probably fine regardless of what it actually it. But I think the best thing would be to find whatever identifying marks are on it and figure out for certain what it is.

 

[Comodave]

I would much rather know than walk away scratching my head mumbling hmmm.

 

[hobbystuff]

I'm going to stick my head in there with my phone and grab some more detailed pictures. However, I am leaning to the conclusion that it is a check valve, probably installed to allow easy removal or isolation of the pump if required. If this is in fact the case, there is no harm in leaving it in place.