How to change the filter for transmission/hydraulic oil without changing oil?

[SmallChange]

Just did my 50 hour first maintenance on a new tractor (New Holland WM25 with manual gearbox). This tractor has a common sump for the transmission oil and the hydraulic fluid, so it's just one fluid. Maintenance schedule calls for the suction filter on the transmission/hydraulic oil to be changed at 50 hours and then at every 250 hours. It also calls for the fluid itself to be changed but only every 500 hours.

So I tried to do this today. I was following the Manual, though at some point I thought, "Suction filter? Huh, I guess it operates at negative pressure or something."

And close to 6 gallons of oil rapidly poured out when I got the filter off. It's the lowest point in the system, and I don't see any shutoff. The manual says nothing about it.

So, two questions:

1) I'm not starting or moving the tractor, and all implements were already resting on the ground and not in float, but it's going to sit maybe 3 days before I can get fluid, so, after I replace all the fluid, will I have to do anything else like bleed the system or prime some pump to fix air in the wrong places?

2) How was I supposed to do this? The 500 hour service intervals will be fine, as I will drain the fluid, change the filter, and replace the filter. But the intervals at 250, 750, 1250 et cetera are called out as filter change only, no fluid change. How am I supposed to do that? The fluid pours out so fast!

Thank you!

P.S. Just to be clear, this is only the transmission/hydraulic oil I'm asking about. Engine oil and filter are a whole separate deal and that went just fine.

 

[3gunr]

If you drain the fluid into a clean container , just pour it back in. Some use a shop vac . putting it over the fill spout with a small nozzle . it creates enough suction to keep the oil from draining. I have not tried this but others on here say it works.

 

[jaydee325]

SmallChange,

Chalk this up to a lesson learned.

For others, make sure you understand what to expect whenever you open any system on a tractor. If you question the manual, ask some questions before opening the tool box!

When I did the 50 hour service on my tractor, I was ready. Big pan under the filter and new filter in hand ready to screw on as soon as I dropped the old one. I had to add about 2 quarts to bring it back to full. Yes, I'm aware of the shop vac trick but for me it just does not seem worth the effort considering being prepared to "drop and spin" a new filter on and then add 2 quarts to an 8 gallon capacity system.

 

[mrmikey]

If you can use a vacuum on the reservoir it'll prevent the fluid loss. Just make sure it's on suck and not blow, ask me how I know (that sounded almost erotic in a sick sort of way LOL)...........Mike

 

[Captain Dirty]

Just did my 50 hour first maintenance on a new tractor (New Holland WM25 with manual gearbox). This tractor has a common sump for the transmission oil and the hydraulic fluid, so it's just one fluid. Maintenance schedule calls for the suction filter on the transmission/hydraulic oil to be changed at 50 hours and then at every 250 hours. It also calls for the fluid itself to be changed but only every 500 hours.

<snip>

How was I supposed to do this? The 500 hour service intervals will be fine, as I will drain the fluid, change the filter, and replace the filter. But the intervals at 250, 750, 1250 et cetera are called out as filter change only, no fluid change. How am I supposed to do that? The fluid pours out so fast!

As one who had your experience, I used the shop vac trick at 400 hours. See link: https://www.tractorbynet.com/forums...2-kubota-l45-hydraulic-fluid-maintenance.html[/HTML][/URL]

 

[SmallChange]

Well, it is indeed a lesson learned!

It did, thinking back, take me quite a while to get the change done. For one thing, I generally don't unwrap new parts until I have the old one off, because sometimes it becomes clear at that point that I need to return the new part. So, I didn't have the new part at hand, I had to get up and open the box and pull it out first. I also had trouble spinning the new one into place. I tried several times, and it would go on a few turns but stop before sealing. I still don't know what was going on there; seems like crossed threads, but it did make several turns easily and stop pretty solidly, so maybe something unseen got in the way. I spun the old one back on to stop the flow and examine the new one. And of course the old gasket kept staying with the tractor and then falling into the pan so I had to fish it out a couple times.

I wondered if a vacuum would help. Now I know it's OK to try one.

 

[SmallChange]

I do still have a question, though -- do I need to do anything special because it's sitting so long without oil? But at this point I'm guessing I just have to replace the oil before moving anything.

 

[SmallChange]

Ah, I got my answer on that, so never mind -- turns out the dealer is open this morning, which is great as I had some logs to move this weekend! And they confirm nothing special to do after refilling. They were a bit surprised, though, how much I managed to lose.

At least I didn't call service people out for a broken transmission because I had a lever in N. So this is hardly my worst goof.

Thanks everybody!

 

[oosik]

At 50 hours I changed every oil/fluid/grease on my tractor. I saved nothing. My big almost "OOPS". The hydraulic system holds 16+ gallons. Thankfully I did a dry run. I could NEVER pull/replace five gallon pails without massive spillage. The only container large enough - my wife's large Tupperware quilt container. A new quilt container cost around $20, as I remember.

 

[Citydude]

Did you get the new filter to seat and seal?