Mixing Hydraulic Fluids

North40 · Jan 14, 2016

I recently bought a Series 1 (SN 17???) D17. Today I put an Allis model 170 loader on it [with trip bucket], which had come off another D17. I hooked the loader's hydraulic hose to the rear-facing transport connection under the seat, like the previous owner had. When I raise the loader, it only comes off the ground about an inch, then stops. It looks and acts like the hydraulic fluid is low, so I want to add fluid to the system.

BUT, I don't know what the previous owner of the tractor used as hydraulic fluid. I've heard some people say they use 10W oil, some say basic farm hydraulic fluid, some say automatic transmission fluid.

My question is NOT "what is the best thing to use in the hydraulic system?", though that would be good to know.

My question is, since there is no way for me to know what's in the system right now, what should I top it off with? Or do I need to drain the whole system and make sure there is only one kind of fluid in it? Would it hurt seals or anything if the wrong fluid, or a mixture of fluids, was put in this system?

Thanks guys.

Dalex · Jan 14, 2016

I would just drain it and start fresh. Walmart
has UTF/Hytran type oil for about $50 a pail .
If the drain oil is not contaminated , save it
for flushing etc....

D beatty · Jan 15, 2016

I would drain and flush system and replace any filter if it has one and refill it with a good grade of ag hytrans hydraulic oil. I use a good grade because hydraulic systems with loaders get a lot more use than a system with out a loader.

jr1983 · Jan 15, 2016

Just add whatever you aren't going to hurt it. That
system is pretty crude. You definitely aren't going to
hurt anything to drain it and start over. I do whenever
I buy a new one but as far as weight goes hytran is
just expensive 10 w like any hydraulic oil. If you have
a modern power shift I would consider somthing
else but a d17 was made to run oil that was roughly
a 10w thickness. Anything they sell for hydraulic
today is going to be fine.

North40 · Jan 17, 2016

Thanks for your answers. I ended up putting in some basic 5w-20 farm hydraulic fluid from Fleet Farm. It was the lightest stuff they had - which I needed, since it's pretty cold here in Minnesota right now (-7F for a HIGH today!). It seemed to work pretty well. But who knows, I might regret it later. If I knew that's what was in the system to start with, I wouldn't worry about it.
Greg

steve(ill) · Jan 19, 2016

5W 20 oil should be fine... no problem.

Mixing Hydraulic Fluids

North40

New User

Dalex

Well-known Member

D beatty

Well-known Member

jr1983

Member

North40

New User

steve(ill)

Well-known Member

Similar threads