OCC Forums

Hydraulics

https://forum.oceancruisingclub.org/Topic7654.aspx

By pete.holt - 2 Sep 2023

Hi All,
Looking for some advice on hydraulics…
I have a navtec system from the 80s, aluminium panel on the pedestal. It controls the vang, back stay and baby stay.
It has stopped working properly. The first pump of the handle is fine, subsequent pumps get more and more ‘play’ in them until about the 10th pump when the pump handle is completely loose. After a few minutes it returns to normal and the process starts over.
Any ideas what the cause might be?
Yep I’ve topped it up with fluid.
Cheers
Pete
By rhudson - 4 Sep 2023


Pete, I have no experience with Navtec, but as a general hydraulic thing, it sounds to me like the seals in the pump are leaking.  You're seeing the amount of play increase the more you pump (so the higher the pressure).  

I would think that any hydraulics shop could test and overhaul your pump if you brought it to them.  It would be a good idea to take a picture of your pump and panel to show the technician in case he asks what it's used for.  And if there are any numbers on the hoses showing the pressure rating, to note or photograph them.

Richard
By pete.holt - 4 Sep 2023

Hi Richard, thanks for your input, much appreciated.
Is your diagnosis consistent with the fact the pressure to the handle comes back after a minute or two of no activity?
Also the pressure on the dial for the 3 different rams doesn’t drop, I can still increase the pressure on the dial, albeit very slowly with lots of pauses.
Thanks
Pete
By rhudson - 4 Sep 2023

pete.holt - 4 Sep 2023
Hi Richard, thanks for your input, much appreciated. Is your diagnosis consistent with the fact the pressure to the handle comes back after a minute or two of no activity? Also the pressure on the dial for the 3 different rams doesn’t drop, I can still increase the pressure on the dial, albeit very slowly with lots of pauses. ThanksPete

Hi Pete,
Sorry, I'm not sure.  Is there a way to bleed the system?  Typically you would want to bleed from the highest point--if there is not a bleed fitting, you could crack open (slightly unscrew) a connection and see if the oil comes out with air bubbles.
Richard
By pete.holt - 4 Sep 2023

Thanks Richard, will investigate further and see what I find