# Hydraulic Oil Grade for Bucket Truck



## cedar

I bought a 1989 GMC Topkick bucket truck today. The previous owner thinks the boom is probably an Altec. 

I want to change the hydraulic oil and filter. What grade of hydraulic oil do I need. In case the boom is not an Altec, do all brands use the same grade hydraulic oil.


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## vandiesel99

I have a GMC Topkick with a Teco boom on it. The factory specs it to take some type of aircraft grade hydraulic fluid. Its $64 per 5'er. I use the cheaper stuff, against recommendations. Don't know what the consequences will be yet.


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## zsteinmetz

you will want to use a non conductive grade of hydraulic oil. Aircraft oil is one type and non conductive is usually red in color. If you switch to another type of regular hydraulic oil the oil your truck will no longer be insulated if you were to come into contact with a power line.


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## bushinspector

zsteinmetz said:


> you will want to use a non conductive grade of hydraulic oil. Aircraft oil is one type and non conductive is usually red in color. If you switch to another type of regular hydraulic oil the oil your truck will no longer be insulated if you were to come into contact with a power line.



Yep, he is right on with his advice!! I am running Dextron in ours. Be carefull, sometimes vendors try to sell you higher price oil due to the non conductive types of oil. Many oils are non conductive.


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## Kgw51gmc

mine has clear-to-brownish colored (But clean looking) oil. I am assuming its the regular "ISO 46 hydraulic oil" from Tractor supply is what you could use. That or AW 32 hydraulic oil which I think is thinner. Going too thick stresses seals and pumps and more. I'm not sure about conductivity. My boom is a thick steel boom, so won't matter to me. Hydraulic shop guessed aw 32 on my boom. So you still have no direct answer !


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