Silvey Tree Jack oil

[Bubba Stump]

Anybody out there familiar with the Silvey Tree Saver back pack unit? I bought the whole setup from a timber faller in Oregon and had it shipped to New Mexico. When it got to me the hydraulic oil had leaked out of the reservoir and was almost empty. I called Madsens to see what oil they recommended and they told me "Mobil DTE 21 hydraulic spindle oil". Apparently, This oil is hard to get and only comes in huge 55gal barrels. Does anybody know if AW 32 hydraulic oil will be OK to use or maybe another kind of oil? The only thing I could find out about the DTE 21 is that it is a ISO 10 which AW 32 is also. What do other Fallers out there use as a Substitute for the Silvey Tree Saver oil?

 

[2dogs]

I think any generic "hydraulic jack oil" will be fine. AW36 or AW42 should be good also. If the oil has already leaked out you ought to go to the auto parts store and get a roll of oil absorbent pads to carry with you.

 

[Bubba Stump]

Thanks for the info, I was not sure if there was some specific reason the Silvey Manual said to use their oil other than they wanted guys to buy from them. The guy I bought the jack system from did not know why Madsens recommended the Mobil DTE 21 oil. He thought maybe the oil had to be a certain viscocity to make sure the tiny check valves worked properly. I got ahold of Borntrager Jacks and they said they use hydraulic jack oil like you suggested. When the jacks were shipped the hand jack ended up upside down and the fluid leaked out of the vent hole in the rubber cap. I don't think the jack has any seal leaks ect. Oh, by the way, I like the quote in your reply.

 

[Jacob J.]

Me and my falling partner ran diesel in our big Silvey jacks for years. The advantage of diesel is that you can find it just about anywhere. I think regular tractor hydraulic fluid is fine though.

 

[Conquistador3]

That's a very very low viscosity ("thin") hydraulic fluid.
If you need small quantities and want to do things by the numbers you would probably be better off running a very thin suspension oil like a 2.5 motorcycle fork oil or a 3wt shock oil. If you just want it to work and spend as little money as possible, put some low sulfur diesel fuel in it.

 

[ironman_gq]

How about ATF? DEXVI is around a 7-8wt and DexIII is 10-11wt.

 

[Bubba Stump]

Well, I called Madsens again this morning and talked to a tech. He told me that their guy that rebuilds Silveiy Jacks was on vacation traveling the world for a while but he always told guys to always use the Silvey Tree Saver oil. Mobil DTE 21 is that oil, just sold as Silvey Tree Saver oil. I researched some on the DTE 21 oil and found it to be a type of Machinist Spindle oil. Apparently the DTE 21 is like a super high performance hydraulic oil that is made to withstand really high PSI without breaking down. The Madsens tech said that, through their experiences, guys who ran fluid other than the DTE 21 always had problems with seals blowing out. I asked him if there was another fluid that could be used as a substitute and he said that he was not even going to go there because of some blown seal incidents they had. He strongly recommended using the Silvey recommended oil. I ended up ordering Madsens last five gallon pale. Yeah, I said five gallon pail. The Mobil DTE 21 only comes in five gallon or larger. The five gallon pale was $100. The Silvey hand pump takes one gallon so I will have four gallons left over. Oh, by the way, I called Valvoline and they tried to cross reference the Mobil DTE 21 with anything they made and they said they could not find anything with the same properties as the DTE 21. I don't know if another oil would have worked just fine or not but I figured Madsens has been in the industry for long enough to know their Sh*t, so I did what they and Silvey recommended.

 

[Bubba Stump]

I had emailed Bailey's to see what they thought and they just left me a email saying that Mobil DTE 21 is the best oil to run in the Silveys but AW36, AW42 or any generic hydraulic jack oil would work in a pinch. The AW36, AW42 and the generic jack oil may not perform as good in lower outside temps than the DTE 21, also, they might need to be changed more regularly and they do react to the seal rubbers differently than the DTE 21. So really, I think you could use whatever rocks your boat. I guess I will be good for the rest of my life with the supply of Mobil DTE 21 I ordered from Madsens. The suggestion of Diesel fuel in a pinch was interesting though, thanks.