changing HST fluid based on age vs hours?

[adlertom]

I'm approaching 100 hours on my New Holland TC33DA after 3 1/2 years of ownership (I use the tractor about 30 hours per year).

I did the 50 hour maintenance a few years ago, which called for replacing the HST filter but not the fluid. I appears that changing the HST fluid itself isn't called for until 300 hours.

At my rate of usage, 300 hours will take me about 10 years to reach.

Should I consider replacing my HST fluid before then, simply based on age? I know this sort of thing is recommended for automobile oil changes i.e. "3000 miles or 6 months".

 

[RalphVa]

The only reason for changing the hydraulic fluid other than very slow deterioration ,(I'm talking more than 10 years) due to oxidation, etc. which will cause some seals to start leaking, is to keep the filter from collapsing from too much debris collecting on it. I don't change (standard) transmission fluid until the transmission seals show signs of oil slinging. This is usually up around 15 years or so. A change almost always stops the slinging.

I'd change on hours only. On my tractor it's 200 hours.

Ralph

 

[WilliamBos]

What about condensation? That is one factor to consider? JMHO, For the cost of a transmission, I would change it by time, and not hours. 10-15 years is too long.

 

[Mighty Dodge]

I read somewhere that one of the causes of hst failure is condensation. It builds up when the tractor isn't used enough to heat the oil up really well. My manual says to change it at 500 hours. I put about a hundred hours a year on mine and plan on changing it every other year. I change the engine oil in the fall and grease it every 50 hours.

M.D.

 

[CurlyDave]

...and grease it every 50 hours...

MY owner's manual calls for grease every 8 hours. You might want to look up what yours says.

 

[tsterkel]

As I am still "tooling up" on my farm, my hours per year is building, but low by other's standards. I will drain every 100 hours, due to condensation concerns, until I get the hours/year up, then go to the manual of 500 hours.

 

[Mighty Dodge]

Oops type-o grease it every 10 hours or monthly whichever comes first.

M.D.

 

[Soundguy]

I change my hydro fluids by hours and or time.. whichever comes first. IE.. for instance.. 300hrs.. or 2ys.. this gets water out of the system if nothing else..

soundguy

 

[john_bud]

After seeing the insides of tractors that have been maintained by folks that don't change by time, my opinion is strongly that you ALWAYS change by time and/or hours. Great gobs of grey gooey gunk in a rusty case- yuck.

There was a post in the ATV forum about a Kubota RTV owner (I think) that would run the machine for just a couple minutes then shut down during the winter. Never letting the machine get heated up and worked while hot. It built up a lot of moisture on the order of qts.

Think of that as you operate those 30 hours per year and don't change the fluid for 10 years. I doubt you are operating it hard enough or long enough to burn out the condensed water and fuel that is building up in the fluids. Rule of thumb is that you should operate diesel equipment for a minimum of an hour AFTER it gets up to operating temperatures to get out condensation. Plowing (dirt), discing, mowing etc are all great activities for doing that. Snow plowing for 20 minutes at 0F then putting the machine away is the opposite.

Oddly enough, lightly operating a tractor at 1/2 throttle for 20 minutes then shutting down is severe use - bordering on abuse!. Working hard in 100F heat at full throttle PTO speed for 8 hours straight is not. (at least not for the tractor).

jb

 

[adlertom]

Thanks to all for the advice. I think I will change the fluid at my upcoming 100 hour service, just to be safe. I plan on having the tractor for a long time and want to avoid potential problems.