642 Hydraulic Fluid Options

[Dantra]

I'm pretty sure that the 642 that I just picked up, has hydro fluid in the tank. I've read that 10w30, 10w40 and 15w40 are what is typically used. I keep AW32, 5w20syn and 15w40 in bulk.. not looking to keep anything else.

I'm in Indiana and wondering if the 15w40 would be fine to use? I'll use the machine this winter for snow removal. Fluid capacity ?

I need to pull the control valve to freshen it up the seals (drippy) so now would be a good time to make any changes.

Thanks

 

[koko]

Use the AW32.

 

[Wayne440]

With those 3 to choose from, and considering the application, I too would use the AW32.

 

[cdmccul]

Where does aw32 fall in the viscosity hierarchy there? I would have guessed aw32, but not for any educated reason...

 

[Mustang Guy]

Where does aw32 fall in the viscosity hierarchy there? I would have guessed aw32, but not for any educated reason...

ISO AW 32 viscosity index is par with SAE 10 engine oil.
I use ISO AW 32/46/68 multi vis hydraulic oil in all of my equipment with no problems - or worries about the ambient temps being too high or too low.

 

[cdmccul]

So it's heavy enough for wear protection, but runs thinner for colder temps, but not too thin to leak past every seal...?

My 632 has been groaning in these really cold North Dakota days. At least till I've been running the arms up and down for 10 minutes. If I try to move the machine too soon after I start it, the engine bogs down and stalls.

I'll have to start exchanging my fluid out I think.

 

[dfb]

Does AW32 hydraulic oil have the lubricity properties required of a hydrostatic system is the question I would have in deciding. After having to rebuild both wheel motors in my 742B that had AW32 in the system for not that many hours, I decided to swap it out for the Bobcat fluid to remove any doubt that the correct stuff was in there. To me, the piece of mind the drive system was lubricated properly was worth the difference the OE Bobcat fluid may have cost. Particularly after realizing that replacing the drive motors would have been a very expensive job had they not been repairable with just a reseal. HTH.

 

[Jyuma1]

Why is there even a question? Using what the manufacturer recommends removes any questions/doubts.

My Thomas T133 manual recommends 10W30 motor oil for the hydraulics. Why would I use anything else?

 

[Mustang Guy]

Why is there even a question? Using what the manufacturer recommends removes any questions/doubts.

My Thomas T133 manual recommends 10W30 motor oil for the hydraulics. Why would I use anything else?

Having worked in a major truck manufacturer's R&D shop I can honestly say that they don't always recommend or use the best suitable products. I have also been involved in lube oil testing and selection with Caterpillar and EMD engines (Before they were the same). Keeping technical specifications ambiguous creates brand dependence and loyalty, and that increases sales and profits. Example:
Does Bobcat state that their oils meet or exceeds SAE, ISO VG, DIN, or ASTM specifications?
Become quasi-educated with this short read:

https://www.machinerylubrication.com/Read/29715/hydraulic-engine-oils

 

[Mustang Guy]

So it's heavy enough for wear protection, but runs thinner for colder temps, but not too thin to leak past every seal...?

My 632 has been groaning in these really cold North Dakota days. At least till I've been running the arms up and down for 10 minutes. If I try to move the machine too soon after I start it, the engine bogs down and stalls.

I'll have to start exchanging my fluid out I think.

Not sure of your location, but some of these are used in Alaska and in the Yukon.

https://petroleumservicecompany.com/iso-vg-22-cold-weather-hydraulic-oil/

 

[cdmccul]

Not sure of your location, but some of these are used in Alaska and in the Yukon.

https://petroleumservicecompany.com/iso-vg-22-cold-weather-hydraulic-oil/

Central North Dakota. We get hot days, but we get a whole lot more cold ones!

 

[Jyuma1]

Having worked in a major truck manufacturer's R&D shop I can honestly say that they don't always recommend or use the best suitable products. I have also been involved in lube oil testing and selection with Caterpillar and EMD engines (Before they were the same). Keeping technical specifications ambiguous creates brand dependence and loyalty, and that increases sales and profits. Example:
Does Bobcat state that their oils meet or exceeds SAE, ISO VG, DIN, or ASTM specifications?
Become quasi-educated with this short read:

https://www.machinerylubrication.com/Read/29715/hydraulic-engine-oils

That may be true, but is it always true? In the case of my T133, Thomas didn't recommend a particular brand of 10W30, just 10W30 API SE/CD.
Thanks for the read.

 

[Jim A]

My New Holland manual says 10W -30 motor oil. All I use in cold weather.
But I never ran in -20° cold .