Any recommendations? A rear mounted pump on a D2-5J operating a 6 way blade. It also has a couple quick commects on the rear. I'm replumbing the hose syatem and what came out is very black and heavier than what I'm used to seeing.

Normally the Cat systems use just a straight #10 oil in the hydraulic systems but not sure if that is what you should use.It may call for regular hydraulic oil but I,m sure someone on here knows what your system uses.

I don't know what was recommended originally but I use hydraulic oil ISO 46 (about a SAE 20wt) in the BeGe pumps I have. The circuit and tank capacity are pretty small, the circulation rate is high with not much capacity for heat rejection so my logic is to run a higher visc. oil than the usual 10wt in the Cat systems.

The recomandation is straight 30 weight, not hydro, not 15/40 not 10, 30wt only in a BG pump, IO used to run a hydro in mine to be compatible with other tractors but when it was sent out ot be rebuilt the builder told me that the type of wear in it was from other than 30 wt.

30wt seems pretty heavy.....I think I will stay with hyd oil and the anti rust and anti foam agents and think about upping the viscosity. Does anyone have an actual spec sheet for BeGe requirements......and how it might translate to todays lubricants?

From form #BG-500 dated 5/53. Use good grade of motor oil or hydraulic oil - In Summer S.A.E. 30 Visc. @ 100 F. -500 S.S.U., Visc Index - 80 Min. In Winter S.A.E. 20 Visc. @ 100 F. - 300 S.S.U., Visc Index - 80 Min. Below Zero ( Same as winter but Watch Pour Point, and warm up equipment slowly. Note: Use an oil with a HIGH VISCOSITY INDEX, at a sacrifice of other characteristics. DO NOT use hydraulic brake fluid, aircraft hydraulic fluid, low viscosity naphtha base motor oils, or oils that have a tendancy to foam. We used in later years ATF to work with the rest of our equipment and found it satisfactory. I have several different arrangements of Be-Ge's and used parts available.

All of above will work if it was closed system and only did the dozer. But when you hook up the remote hyd. to anything that is shared with modern tractor you are useing that requires torque fluid the next time you hook up to newer tractor after useing this one you will contaminate the its hyd system and eventully cause internal problems in newer machine. Torque fluid or called (tractor trans. fluid) is what is used in most newer machines as the have only 1 system that runs the whole tractor(trans., internal hyds., and remote hyds.) and it takes much higher temps without breakin down which is required in the trans and close tolerances of the newer machines.
Any wear in your old system most likley came from getting hot and cheap oil breaking down and not lubricating properly not from just using other oils alone. Oil only causes wear when it gets hot and breaks down or gets contaminated.
The heavy stuff you had in it was old trick,put in heavier oil to make more presure out of worn system.
So spend the extra buck and buy the good stuff.

Thanks for the lube specs:)
Good info on cross contamination.