Hilbilly
Veteran Member
I'm getting close to finishing my hydraulic power pack build and was wondering what others use for hydraulic fluid in their systems.
Hydraulic fluid for PTO power pack?
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Sysop
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- Mahindra 4035HST purchased 2013 - Husqvarna TS348-D purchased 2019 - Craftsman 42" HST purchased 2003
The pump should have specs.
Good point!
I bought the pump at an auction and it didn't come with any paperwork but I did manage to find some specs online. Its a Ronzio pump made in Italy and the spec sheet is in Italian with most info translated. The only reference I found for oils was a recommended Viscosity (at 50*C) of 2,5 - 6,5 E. I did some checking online and it appears to be an AGMA spec. If that is correct then the ISO equivalent is from 100 to 400. This seems to be way too high, especially for operating in below freezing temps. According to another resource, 100 ISO oil temp should stay between 50*F and 200*F. I doubt it would function well in below freezing temps. Might cause pump damage when starting it.
Any suggestions?
Sysop
Elite Member
- Joined
- Jun 7, 2013
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- Fairmont, WV
- Tractor
- Mahindra 4035HST purchased 2013 - Husqvarna TS348-D purchased 2019 - Craftsman 42" HST purchased 2003
Not that I'd wanna bet money on. 
One thing to consider, they're likely talking operating temps, not ambient temps. Also, most hydraulic units warn against putting them under load when cold and that it should be brought to operating temps before putting it under load. Hydraulics also generally get pretty hot while in use and more hydraulic issues are caused by fluid that gets too hot than nearly anything else.
Myself, I would stick with the higher temp fluid and let the unit warm up before putting load on it during cold weather. The only way I would go much lower than spec is if I had a huge reservoir tank that isn't going to heat up much.
One thing to consider, they're likely talking operating temps, not ambient temps. Also, most hydraulic units warn against putting them under load when cold and that it should be brought to operating temps before putting it under load. Hydraulics also generally get pretty hot while in use and more hydraulic issues are caused by fluid that gets too hot than nearly anything else.
Myself, I would stick with the higher temp fluid and let the unit warm up before putting load on it during cold weather. The only way I would go much lower than spec is if I had a huge reservoir tank that isn't going to heat up much.
oldnslo
Super Member
For comparison most universal tractor hydraulic fluids are in the ISO 32-46 range. You will see some ISO 68 also used in mobile hydraulic systems.
I would be hard pressed to use anything heavier than ISO 68 especially in cold weather unless the system will run very warm of the pump truly requires fluid that thick
I would be hard pressed to use anything heavier than ISO 68 especially in cold weather unless the system will run very warm of the pump truly requires fluid that thick
I found some "All Season ISO 68" hydraulic oil that has a minimum start up temp of -19*C. The ISO46 has a min start temp of -22*C. Not much difference. Since I have a small reservoir and the pump spec calls for higher viscosity oil, I think I will try the ISO 68 and if it gets colder than -10*C I'll store the hydro pack in the shop until needed.
Thanks for all the help. Much appreciated.
Thanks for all the help. Much appreciated.