Iso 46 or Iso 68 Hydraulic Fluid

[Beckbenj]

Hi All,

I’m in the process of changing out the hydraulic oil on a Kubota KX161-2. The book recommends shell tellus Iso 46 for between 20F and 70F, and Iso 68 for temperatures up to 90F. With my being in northern Ohio, I don’t expect to see long periods at the upper temperature range.

I’ve read several opinions on which oil to use, some comments mentioning a heavier oil should be used on an older machine due to parts having wear, etc. My KX has about 3,700 hours on it.

Any opinions on Iso 46 vs. 68? Or should I consider a multi weight oil?

 

[IceHole]

I've always used ISO 32 in everything at home. At work it's ISO 15

 

[Nige]

For your location I would suggest to go with the 46. Generally 68 is used in semi-tropical conditions and your location certainly is not that......

 

[James Sorochan]

I would go with the 46W. I just did our Kubota 121-3 and used the Kubota All Season hydraulic excavator oil. I'm in southern Alberta so we have a wide temperature range during the year. ( -40 to +40 ) I wouldn't run the equipment at the extremes though.

 

[KSSS]

I put new fluid in my Taki and Link Belt and went with 46HV which is a multi weight. Its green in color.

 

[Beckbenj]

Thanks guys. Iso 46 it is. I haven’t been able to find info on the temperature ranges for the HV, but that’s interesting to me as well.

 

[IceHole]

Thanks guys. Iso 46 it is. I haven’t been able to find info on the temperature ranges for the HV, but that’s interesting to me as well.

I use Rando HDZ. Don't have the spec sheet handy (on potato internet) but the 32 is around -50* and the 15 is -80*

 

[1693TA]

We had a similar problem with hydraulic drive oil system on an antenna array and I sourced a thermostatic controlled oil cooler array, coupled with power operated shutters offering 86% airflow restriction, and of course a blower assembly coupled to the shutters operation. All said and done this worked very well at controlling oil temperature and viscosity throughout ambient temperature swings. This system operated with conventional ISO46 oil all year round and never had problems afterward.

 

[Syleng1]

Not to side track the original posters question but since we are further down the path. ISO is zinc free correct ?
AW is zinc enriched.

My apologies OP.

 

[Nige]

Not to side track the original posters question but since we are further down the path. ISO is zinc free correct ?
AW is zinc enriched.

In a word, no.

ISO (International Standards Organisation) is the metric equivalent of the SAE. So any particular ISO 46 hydraulic oil can either be zinc-free (aka ashless) or can use a zinc-based anti-wear additive package. You have to look at the spec sheet or the sales blurb to determine which one.

 

[Syleng1]

In a word, no.

ISO (International Standards Organisation) is the metric equivalent of the SAE. So any particular ISO 46 hydraulic oil can either be zinc-free (aka ashless) or can use a zinc-based anti-wear additive package. You have to look at the spec sheet or the sales blurb to determine which one.

Thank you again Nige! You’re a rock star!

 

[Beckbenj]

Coming back to this thread,
It is now mid 80’s here in northern Ohio. Should I be concerned with running the iso 46 oil in these upper 80 temps?

 

[IceHole]

Coming back to this thread,
It is now mid 80’s here in northern Ohio. Should I be concerned with running the iso 46 oil in these upper 80 temps?

46 is fine.

 

[Nige]

Coming back to this thread,
It is now mid 80’s here in northern Ohio. Should I be concerned with running the iso 46 oil in these upper 80 temps?

I don't see why not. It's not like the temperature is going to be that high year-round.

 

[Beckbenj]

I don't see why not. It's not like the temperature is going to be that high year-round.

To be honest I don’t fully understand if there would be risk of hydraulic system damage due to overheating, etc.

It seems the concern is more oil degradation at the higher temps?

 

[Nige]

To be honest I don’t fully understand if there would be risk of hydraulic system damage due to overheating, etc.

It seems the concern is more oil degradation at the higher temps?

No and no. The cooler should be just as capable of preventing overheating whatever oil viscosity you use. You just need to make sure it’s clean and that the air from the fan is not escaping around the sides. All the sponge baffles should be present and in good condition.

A lot of other brands of machine use ISO46 or even SAE10W (somewhere between ISO25 & 32) year-round in hydraulic systems.