hydraulic steering

Aviatar · Aug 7, 2023

A nut came loose on my Sea star power steering line which caused fluid to leak out and I lost my steering. This happened while I was in a bass tournament. I was unable to find marine hydraulic fluid to replace the fluid I lost. A local automotive store said it was OK to use ATF fluid, so I topped off the reservoir (about 4 oz.) and continued the tournament. It worked fine. Here's my question. Do I need to drain this hydraulic unit and replace with all new marine steering fluid? Or can I just operate as is? Thanks for any help I can get.

Callaojoe · Aug 7, 2023

I'd probably bleed & refill it myself, it's not hard to do. ATF has less viscosity, so not sure I'd tempt it.....

But, maybe more savy boaters would know better. Did the loose nut introduce bubbles into the system?

I'd be worried about slippage in the steering possibly.....

Aviatar · Aug 7, 2023

Yes, the loose nut got air in the line. I bleed it out as I added the ATF into the system. I got all the bubbles out and there is no slippage at all. Actually, I had about 4 oz. of hydraulic fluid with me which I used first but it was not enough to bring the steering back to normal.

PS Thank you for your input.

olefisherman456 · Aug 7, 2023

i had a trim unit rebuilt by a guy with many years experience . he told me to use only red power steering fluid. large shop rebuilds hydraulic cylinders for heavy machinery . or will build a new one.

jerry shack · Aug 8, 2023

Aviatar said:
A nut came loose on my Sea star power steering line which caused fluid to leak out and I lost my steering. This happened while I was in a bass tournament. I was unable to find marine hydraulic fluid to replace the fluid I lost. A local automotive store said it was OK to use ATF fluid, so I topped off the reservoir (about 4 oz.) and continued the tournament. It worked fine. Here's my question. Do I need to drain this hydraulic unit and replace with all new marine steering fluid? Or can I just operate as is? Thanks for any help I can get.

Most defiantly purge the whole system, and replace with Sea Star fluid . There steering fluid is special for the steering pump at the helm. It has anti-corrosion properties and non acid cleaners in it. Automotive and truck hyd. cylinders can use transmission fluid (red) because of the non-foaming properties in it and the high temperature usages. However one or the other will work, but I don't think I would mix it.