Delay in adding back hydraulic oil?

[gwisejr]

Good afternoon,

I started to do my 50hr first maintenance on my Branson 3520H tractor two weeks ago. I replaced the engine oil and front axle oil. The emptied the hydraulic oil. Then when replacing the hydraulic filters, I discovered that the wrong ones were sent. So, I have the correct ones in had and I was planning on finishing this weekend, but got sick and will have to do it next week. My question is, the tractor has been sitting with no hydraulic fluid for not two weeks and possibly another week. Everything is sealed up, I had left the old filters on and of course closed the drain port. Is there any potential damage in not having any fluid in the system for so long? I thought to re-add the old fluid, run it for a few minutes, then drain and replace it along with the filters.

Any thoughts or guidance?

Thanks.

 

[RjCorazza]

I wouldn't worry about it, and would certainly NOT put the old fluid back in - too much risk of contamination. The hydraulic fluid is pretty heavily filtered by all of the machinery I am familiar with, but there is no sense in tempting fate.

 

[Granthol]

For a week, sealed up, I’d say your ok. Take the key out just so no one possibly starts it without fluid in it.

 

[ericm979]

It'll be fine. Just don't run the engine until the transmission is full again. The pumps will suck air and possibly be damaged.

BTW it's easy to overfill and get the level above the sight glass. Many transmission fluids are not dyed and will look clear in the window making it hard to tell if the fluid level is above the window or below. So go slow once you get close to the stated refill capacity. My 3725 needed close to another gallon after running it a while.

 

[RickB]

Just pull the drain plugs again before you fill it. You may be surprised how much oil has drained down from the nooks and crannies while you were away.

 

[Hayloft]

I also recommend making sure the tractor doesn't get started by accident before you get it refilled with oil.

You should be fine for just a few weeks but over a longer term without hydraulic oil I'd be concerned with condensation. Some water always gets in the hydro oil but normally not enough to bother - you'd be able to filter it back out along with dirt & debris from normal operation. Filter changes help keep all this unwanted stuff out of your oil as much as possible. Just be aware and try to minimize oil contamination.

Like others, on my 3520H oil changes I found it slow to refill fresh hydro oil due to the design of the oil fill port. Try to pour too fast and it will overflow. Ugghh. A small oil transfer pump was suggested by someone and sounds like an improvement to me - think I'll give it a try next fluid change.
Good luck - that's a nice tractor. It will work hard for you.
Regards

 

[LouNY]

Some people have had difficulties getting the hydraulic pump to prime.
After leaving it to sit that long with no fluid in it the pump has quite likely allowed more then usual fluid to drain out.
These are open center systems which should prime easily but it wouldn't hurt to remove a hose on the main pump and back fill it a bit,
it could be completely unnecessary, I don't know for sure.