White or red hydraulic oil ?

[BartW]

I just had service done on one of the passerelle cylinders (new seals)

The hydraulic systems on passerelle, rudders, and hi-lo platform have “white” hydraulic oil inside,
the oil in the trimflaps is red. (same for the flaps on my Karnic)

What’s the difference between White and red hydraulic oil ?
Which type is used for which application ?
Can they be mixed ?

One last question, what is the method for bleeding a hydraulic cylinder ?

many thanks for advice!

 

[volvopaul]

White is pure hyd oil , red is for transmissions and power steering systems.

 

[birchwood330]

Yes , red is ATF (Automatic transission fluid) and is better for steering systems , trim tabs etc as it has better cold weather properties.
ATF and mineral oil should not be mixed. Mineral oil should be clear though , white means its got water in it and is probably why the seals have gone

These cylinders should bleed themselves by fully opening and closing them a good number of times. You can crack the hose at each end and turn to cylinder accordingly but it makes a mess and not really necessary for this sort of application.

 

[BartW]

Mineral oil should be clear though , white means its got water in it and is probably why the seals have gone

My mistake, I mean "clear" instead of "white", system didn't have any water in it.

actually there was a leaking hose in the system, that was the reason for my disassembling, One pair of hoses is sharply bended during every deployment, and has to be replaced every second season according the privious captain,
will post pictures after reassembling.

but I had a suspicion about this cylinder aswell,
very difficult to see where oil drops were coming from, hose fitting or seal,
and had it tested anyway,
the service guy told me that the seals were still ok, but very old, so he replaced them while all was disassembled.

thanks a lot for the explanation

 

[birchwood330]

Could be worth fitting a swivel coupling in the hose which would allow it to move and not kink.

 

[tinkicker0]

I just had service done on one of the passerelle cylinders (new seals)

The hydraulic systems on passerelle, rudders, and hi-lo platform have “white” hydraulic oil inside,
the oil in the trimflaps is red. (same for the flaps on my Karnic)

What’s the difference between White and red hydraulic oil ?
Which type is used for which application ?
Can they be mixed ?

One last question, what is the method for bleeding a hydraulic cylinder ?

many thanks for advice!

White hydraulic oil will usually be aquacent oil that is used where fire resistance is paramount.

 

[BartW]

Could be worth fitting a swivel coupling in the hose which would allow it to move and not kink.

good idea, but its a bit more complicated then that,
will post pictures when at the boat, and consider your idea again...
thanks!