B1700 HST: overfilled transmission fluid a problem?

[tbronson]

B1700 HST. Seem to have overfilled with topping up the transmission fluid after replacing a removed cylinder on the loader. Used the loader for an hour, no problem, before checking the level.

The dipstick is showing about an inch above the fill mark. When I look into the tank itself, there seems to be a lot of space, I can't even see the fluid. Is this a problem? Do I have to drain off some fluid?

I googled it and read several posts and articles, and the conclusion seems to range from not a problem if not full to the top of the tank, to potentially big problem: air bubbles, fluid contamination, and some other stuff.

 

[85Hokie]

The problem is "foaming" - an oil level is a certain point where moving parts do not whip the the oil to a frenzy thus making air bubbles in it.

I would go ahead and climb under - and pull the plug and allow some to come out.

OR ....this works real well if you have the tools! Get a large syringe (50 cc ) and place a piece of clear hose on the end and simply suck out until you lower the level. I had to do this on an air compressor after changing the oil and "washing" it out..... takes a few pulls on the syringe but the lack of mess is worth it!

 

[Roadworthy]

Going a little above the full mark is one thing. An inch above is quite a bit. I'd attempt to remove some via suction. Harbor Freight has a couple of cheap suction pumps that would do it.

 

[tbronson]

Thanks for the replies!

The problem is "foaming" - an oil level is a certain point where moving parts do not whip the the oil to a frenzy thus making air bubbles in it.

Good description. It makes perfectly clear what I read elsewhere.

I'll get the level down.

 

[twomany]

Just an observation, and can not comment on ALL the possible ramifications, BUT.......

Last year the 3 point lift on my B7200 HSD got a bit stick. I pulled the rear end top cover as it contains the hydraulic cylinder. Once the cover is off, I was looking right in at the top of the major fluid reservoir. An additional inch of oil would make absolutely NO DIFFERENCE to any concerns regarding splash or foaming.

Just an observation, you should do what you feel right.

 

[ACDII]

Usually foaming happens with low fluid levels in an HST since the parts are pretty much submerged. In a reciprocating engine too high of a level does cause foaming as the crankshaft is splashing around in the oil causing it to foam. Too much fluid though can cause seal failure, and depending on where the returns enter the case, backflow issues when not running. Also consider that the tractor is not always level when in motion but at varying angles in several different directions, and too high a level can cause issues not thought of when flat and level.

Better to drain some out that run too much.