Navtec hydraulic backstay adjuster

[mikefossl]

Having neglected a small leak for a long time I found myself in Ishigaki, Japan with a non functioning backstay adjuster. When I released the tension after our arrival, it no longer pumped fluid. On inspection I found no oil to be seen at the bottom of the fill hole. We searched around locally for the ISO 32 non detergent hydraulic oil but could only find hydraulic oil for marine steering. The viscosity and color looked right so we went ahead. $35 for 2 liters of which we used 300 mils.

Everything seems to work fine and I tightened the leaking set screw so we should be good to go.

Any comments on the suitability of the steering fluid?

Thanks!

[avazquez]

Next time fix the unit yourself. It is very simple if you are careful. Get the seals in the web and also the repair manual. I agree that every boat owner should be able to repair every piece of equipment. It is nonsense to spend hundreds of dollars to send a simple piece of equipment to get it repaired. Any decent hydraulics specialized shop can do it for a fraction of what Navtec dealers charge.

[bstreep]

As long as the viscosity is similar, you should be fine. The backstays are fairly simply hydraulics, as noted above, and can be fixed by anyone familiar with them (this is NOT true of Navtec boom vangs, which can be dangerous). The way the backstay units are installed, the seal gets exposed to sunlight, and degrades. My better half made booties for ours, out of Sunbrella.

[delmarrey]

As a hydraulic specialist I can tell you that the oil used in back stays is basically 10W fluid with moisture inhibitors. That's what Navtec uses. In a pinch ATF (Dexron III) can be used but it has no moisture inhibitors and should be changed out ASAP. ATF uses heat to reduce moisture. ATF will also mix with the existing oil.

[delmarrey]

Originally Posted by bstreep

My better half made booties for ours, out of Sunbrella.

Me too!

Also, I covered the hyd hose with wire loom casings.