Is it true....

[foxgoose]

That current Volvo KAD 43's use engine oil in the power steering and leg trim hydraulics?

My new boat came from Botnia with a comprehensive range of top up fluids in different sized labelled plastic bottles - all fitted in a neat plastic box in the lazarette.

The fluids for the PAS and leg trim are labelled "Engine oil" with the right SAE no. and look and smell like engine oil.

Primary steering circuit and trim tab fluids are proper hydraulic fluids.

The manuals (which I naturally got around to reading just after I'd topped up the systems) are ambiguous. Main engine manual sez use hydraulic fluid for both. Separate steering pump manual sez use engine oil. No separate manual for leg trim system.

Visitors to boat with much more experience say they've never heard of such a thing and I've probably f**cked my systems up.

Oh dear - help please!

 

[longjohnsilver]

I don't pretend to be a hydraulic expert but have been told that you could use water without it doing lots of harm, so presume that engine oil as opposed to hydraulic fluid can't be too bad.

 

[aztec]

don't know if this will be a lot of help, but i'll post any way.

a while back, some idiots on a site, put engine oil into the brake and clutch fluid resovoirs, on a number of industrial dumpers, the oil made the seals swell, and stop working.

then the seals needed replacing. i'm not sure if engine oil will effect your steering or drive legs as both fluids are mineral based. but please check before sending this fluid round your system. and as long john says, you could use water, but water is neutral, if there is already lubricant in the system. the problem is not the ability to compress the fluid, but the effect the fluid has on the seals.

hope this helps, but seek advice of some one who knows.

regards, steve.

 

[BarryH]

Don't know if its the same, but when we had a Mariner outboard, the trim and tilt mech used engine oil. Would have thought the steering used proper hydraulic stuff tho.

 

[aztec]

there you go then, i didn't know that, sounds like it's ok to use. if the seals in the steering rams are of the same material, then there's your answer, but get confirmation from experts.