Identifying Blue Hydraulic oil..........

[2 stovebolts]

I installed a new Gilbarco single post lift in my garage back around 1984. The dealer sold me a barrel of Drydene Blue Hydraulic oil....Now I'm ready to do a top off of the reservoir, & bleed the air out of the system. Unfortunately I do not have the specs of the Drydene oil, & the Gilbarco manual states use 'viscosity 150-200 SSU @ 100 degree oil. I contacted Drydene, & they are out of business & sold to another company...This other company does not offer the blue oil....I did find that Castrol supplies blue hydraulic oil, however could not confirm the 150-200 SSU specs....So this is where I'm at......One of my questions, Is it an accepted practice to mix color of oils, & what would the best substitute for the 150-200 SSU specs....I have no doubt the dealer who sold me the lift, gave me the correct oil, as they were a big player in gas station maintenance, but unfortunately they too went out of business..... Would really appreciate any feedback...Thanks

 

[Creekside]

I can’t answer your question about that particular fluid as that lift has about 12 years on me. However, I wouldn’t worry as much about color as I would viscosity. Royal Purple is dyed purple and many Schaeffer products are green among other examples. As a wild guess I would pick a hydraulic oil in that weight range(most lifts I’ve seen call for ISO 32 to 46 or ATF.) That is a very basic hydraulic system and I doubt you’ll see any problems with whatever you fill.

 

[2 stovebolts]

In my research I found that today there are 3 basic viscosities 32-46-68....I can't find any reference for 150-200 SSU....so that was my question.....I really want to be certain before I add any oil into the system, as once its in there, it would mix with the other & nearly impossible to pump it out... Is there anyway to check the viscosity of the oil that is in the tank?

 

[Creekside]

You could pull a sample of the old oil and send it off. That would tell you it’s current properties. SSU is Saybolt Seconds Universal and is a measurement standard using a Saybolt Viscosimeter. 150-200 SSU puts you into the ISO 32-46 range.

 

[2 stovebolts]

Creekside...Thank you so much for your knowledgeable responses....I getting on the right track...This really narrows down my search......Thanks again....

 

[George Bynum]

+1 Creekside ... 150SSU@100F would be an ISO32. 220SSU@100F would be an ISO46. I'd be comfortable with either. If in a cold environment, and/or infrequent (less than 50% duty cycle) running, I'd prefer the 32. If in a hot (ambient over 100 or oil temperature over 125F), I'd prefer the 46.

Frequently not understood is that it is good for the oil to be over perhaps 110F as condensation will be evaporated. In industrial hydraulic systems, I want my oil temperature to be over 115F for that reason.

 

[2 stovebolts]

This is a residence, non commercial lift, with only occasional use...with the ups & downs to be very minimal.....sounds like the 32 is the oil.....A great tip I picked up from a distributor is mixing a small jar amount of the existing oil, with the replacement oil...shake, let settle & watch for any reaction...If nothing, then I'm good to go....Cobwebs in my old brain, should have thought of that.....Thank you both...information & advise is priceless....