My Tractor Forum banner

1 - 4 of 4 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I picked up a 96ish simplicity sovereign with triad engine after adjusting lifters
And carb clean got it running nice (has 265 hr) but hydro has whining noise
Changed filter and fluid no change
Previous owner pushed tractor without pushing relive valve could this have damaged pump thanks scott
 

·
Registered
Joined
·
309 Posts
Most if not all hydros whine. It's their nature from what I hear from people that have owned hydro models longer than I have.

My Sunstrand 15 whines especially loud in my shed when cold startup and moving slowly to get outside. The faster one goes in speed, the quietier the pump is, as restrictor plates inside pump are more open to allow oil to flow faster and smoother.

Could it be the oil used, possibly? I have straight 30wt Rotella diesel oil in my hydro right now as that's what PO had used. Would it be quieter if I went to a 5-30/40 wt oil? Maybe. Thought of trying it for this next spring to see, unless someone has a reason and says to not change the oil weight to a winter blend oil--and here's the reason(s) why.

If the tractor moves forward/reverse and takes hills with no seem-able problems, then the pulling/pushing that PO did maybe was slow enough to not cause any damage, if over grass, gravel or dirt which the tires can slide on easier compared to pavement.

Del
 

·
Moderator
Joined
·
21,424 Posts
Hydraulic pumps and motors whine as a matter of course. As they work harder, the higher pressure will cause the whine to become louder. High viscosity fluid at lower temperatures is more difficult to pump through the system, which will also cause the pressure, and the whine, to increase.

There is a wide variety of fluids that will work for the older hydros. Engine oil, both single and multi-viscocity, ATF type A or F, house brands of fluid recommended for hydros. and quality hydraulic fluids are all included. They will work well, but you do have to take the ambient temperature into consideration. A 30W motor oil will be so thick at subfreezing temperatures when the tractor is first started that the pressure will be well above normal just to move the tractor.

The only way to warm the fluid, short of a heater on the final drive, is to actually work the hydro and hydraulic implement lifts. I exercised all of the cylinders of my FEL equipped GT 2, 3 or 4 times before moving the tractor at temperature ranging down to -30°. Even then, the hydro was slow for the first 10 minutes until the work made some heat in the fluid. Normal operating temperature is 120-180° F.

Oh yeah, my fluid of choice for my Sundstrand for over 22 years was ATF type A/Dexron/Dexron III. It worked well for me from -30 to +90° F. Several other fluids will work as well, but the gas station half a mile from home sells Dexron if I need it in a hurry when the auto parts stores are closed.

Note that while many different fluids will work, the additive packages may not be compatible between types (not brands) of fluid. Don't mix the types in your hydro, or any other hydraulic system.

To the OP, by your description, your tractor seems to have survived the pushing by the previous owner without damage.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #4
Found problem it was bearing on gear driven by hdro pump in axle / lower gear box found used rear end swapped it out
 
1 - 4 of 4 Posts
Top