Mixing hydraulic/transmission fluids

[maxchch]

I just bought a used farmtrac 28hp. The hydraulic fluid is a little low but very clean. I can't fing the maunual recommended Citgo fluid. Pardon my ignorance but can I top it off by adding a different brand or should they not be mixed?

 

[Robin Veerman]

If you could never mix similar fluids due to name brands, doing an oil change would be very difficult to do, out of concern of cross-contamintation. So if you know the type of fluid in the sump you can add a different brand to it, as long as it is the same type of fluid. Hope this helps. It might be a good idea, however, to do a complete oil change on the unit (engine/trans etc) if you have no history of the oil change interval. Dutchy

 

[RNeumann]

An over generalization-

The typical CUT works fine/well with what is known as THF or “tractor hydraulic fluid”. This fluid is designed to work in hydraulic pumps, tractor transmissions, front axles in moderate to cool climates and the wet brakes common in tractors.

With an unknown history, I too would recommend a fluid change. But if I was guessing or didn’t know what to use, it would be THF.

Several folks make a THF. Chevron Delo, Shell and most major tractor brands have a “house” brand of THF. Some of it is even synthetic if that floats your boat.

Enjoy the new machine!

 

[WranglerX]

Any fluid that meets the Citgo "spec" numbers should be ok.... If in doubt about mixing brands, complete fluid change may make you sleep better at night..

Dale

 

[seville009]

As others have mentioned, it’s always a good idea to change fluids and filters after buying used equipment

Even though the fluid looks clean, the prior owner may have just topped it off. You never know what the filter looks like inside.

 

[nyone]

5gal bucket of tractor oil is prety darn cheap. Mixing them all within the same spec isnt a problem. How many hours on the unit? Usualy any machine will have a 1,000hr hudraulic oil change interval even if its clean.

If your tractor sits for a while try next time before you use it crack open the transmission/rear end drain. Usualy after a few days any water finds the lowest point.

 

[ericm979]

If you search you may be able to find a compatability chart that lists the specified Citgo fluid. Failing that I'd use a good "premium" THF. Chevron THF1000 is a good one. It's not that expensive if you can find someone who stocks it. Supposedly NAPA does but none of my local stores have it and shipping is prohibitive. Mobilfluid 424 is a good replacement.

THF is hydraulic fluid with additives, notably to work with wet brakes.

 

[RalphVa]

I doubt these kinds of fluids have very many additives. I would not worry about mixing them. Just make sure to use a lower vis one if you experience winter temperatures.

Ralph