Hynautic Steering Filter Change Tips?

[ThirdHatt]

I had similar Hynautic steering on a couple of my Hatt's, but none have had a filter (to my knowledge) before this one. In the pic below, you can see the white spin-on type filter partially blocked by the cooler for the steering fluid. The filter looks like a typical spin-on oil filter but it says Lenz Company on it so it must be a filter made for this application as Lenz specializes in hydraulic filters, etc.

My question is how can I change this filter without having to bleed the entire steering system? I've bled these systems before and they aren't too much fun so if I can avoid it while still changing the filter I'm all ears. You can see the resorvoir/pressure tank mounted on the bulkhead outboard of the port engine and it is higher than the filter. Obviously I will releive all pressure from the tank but I think the resorvoir is just going to drain when I drop the filter. The big line from the resorvoir goes to the power steering pump, then to the cooler, then to the filter so maybe since the power steering pump will not be running when I change the filter hopefully it may not drain much at all. I'll have the replacement filter filled with the Shell Aero fluid ready to spin on, but how much air will I trap into the lines?

Any thoughts/tips/suggestions are greatly appreciated!

 

[Boatsb]

Why do you want to change the filter? Is it necessary? Is it just a filter? There is a lot of pressure for a spin on filter in a steering system.

 

[ThirdHatt]

Why do you want to change the filter? Is it necessary? Is it just a filter? There is a lot of pressure for a spin on filter in a steering system.

Scott, I have been doing alot of engine room and generator room maintenance lately and this is the one filter that I have not changed. It looks old and rusty, so it MUST be overdue for a change. I am trying to get a baseline on all fluid/filter changes to base my maintenance schedule from, so it's time to change it and know that its good to go.

My broker told me that he was on a sea trial not too long ago on a 2000 model boat and it lost steerage during the sea trial because the power steering filter clogged. That doesn't sound like fun to me, so I would rather change it instead of neglecting it.

As far as pressure, you are right because even though I maintain the recommended 20-25psi in the resorvoir, this filter is after the power steering pump so I bet it is under some good pressure when the engine is running. I see that some of these filters are rated for 200psi+ on the Lenz website, so all the more reason I do not want it to clog up.

 

[Boatsb]

I would see what the manufacturer says about changing it and if it is something to do often I would put valves before and after the filter to isolate it and not drain the fluid when it gets change. They may already be there somewhere.

 

[captddis]

I would blled off the pressure, prefill the new filter and do a quick change and I doubt there will be any problem.

 

[ThirdHatt]

I would see what the manufacturer says about changing it and if it is something to do often I would put valves before and after the filter to isolate it and not drain the fluid when it gets change. They may already be there somewhere.

Good point about the valves. I think Hynautic went out of business years ago, maybe bought out by Teleflex? I'll make some calls tomorrow and see what I can find out.

Thank you Scott, I appreciate your help!

 

[ThirdHatt]

I would blled off the pressure, prefill the new filter and do a quick change and I doubt there will be any problem.

LOL, that is PRECISELY what I am hoping for!

Thanks Dave!

 

[REBrueckner]

When I lost an hydraulic steering line one stormy test trip, only a small amount of fluid leaked out...I guess most gets held in the system via vacuum....

Anyway, once you open the filter unit, if nothing runs out you are (a) either all set for a quick filter change or (b) can install a couple of shut off valves to assure stress free changes in the future....

I added such valves at my steering pump in the event I had to change it out under stressful conditions for a spare so I knew I'd have steering back immediately///

 

[ThirdHatt]

Okay, for anyone interested this is what I learned: I just got off the phone with Teleflex and their part number for the filter is HP6140 and it is a 10 micron filter. They recommend that the filter be changed every 250 hours.

I called Lenz to inquire about the old filter that I have right now and they said that they only sell Teleflex one filter, their model CP-752-10. Good to know that the Teleflex filter is made by Lenz! The interesting thing is that the one place that the Teleflex filter came up on a quick Google search had them for $42 (I have not checked Lewis or Donovan) but Lenz said they sell them for only $6.80 each, so I ordered two and should be good for a while.

Both Teleflex and Lenz said that after bleeding pressure off the resorvoir I should be able to do a quick filter swap with the new filter pre-filled without any bleeding issues. Now I get to test the theory when the filters arrive.

Thanks to those who responded.

 

[JLR]

Byron - call this fellow in Indiana. He was tremendously helpful when I was rebuilding a hynautic head.

Charman Industries Hynautic parts Mike 800-247-6324