L Series Hydraulic Filter Change

Roadworthy

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Lifetime Member

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L2501 HST
Aug 17, 2019
1,649
525
113
Benton City, WA
I've read one should use a shop vac to slow or stop hydraulic fluid leakage when replacing filters. I've not seen any information how to accomplish this. I discovered the hydraulic cap on my tractor was a common on inch male NPT fitting. I grabbed a one inch socket to male NPT adapter, cut a short piece of one inch PVC to jam into it then grabbed a one inch PVC coupler to slip over the other end of the PVC. Putting a couple wraps of biseal tape around the outside of the coupler made it big enough to pressure fit into my shop vac hose. I put it all together, turned on the shop vac to apply a vacuum, and proceeded to replace my filter with only slight leakage.
 
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cliffboyer

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L3301 w/LA525 loader, G5200 mower w/RC48 deck, Kawasaki 610 Mule, DR mower
Nov 30, 2017
240
48
28
Southern IL
Yup, employed same method as well...lost less than 2pts. The larger issue some folks encounter is breaking loose the factory filter with the first change. Between the death‐grip tightening and the paint sealing to the housing, it can be a challenge.
 

number two

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Equipment
B3030HSDC L2501HST
Mar 26, 2021
289
133
43
Northern Lower Michigan
Very cool!
I'll have to try it when my time comes.
When doing my B,the procedure is drop all the fluid,change filters,and refill.
Thanks for posting.
 

number two

Active member

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B3030HSDC L2501HST
Mar 26, 2021
289
133
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Northern Lower Michigan
Yup, employed same method as well...lost less than 2pts. The larger issue some folks encounter is breaking loose the factory filter with the first change. Between the death‐grip tightening and the paint sealing to the housing, it can be a challenge.
Some years ago,I had to use an air chisel to bump loose the hyd filter on a L3540.Tough stuff.
 

random

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Equipment
L3301, bucket, backhoe, grader, plow, harrow, cultivator
Nov 2, 2020
717
401
63
NC
HST or gear?

I read somewhere (here I think) that the hydraulic filter is pressured in a way that the system won't be open to it when not running. (Forget the actual term)

When I replaced mine not long ago, there was very little fluid lost - just a small bit that came out of the filter when I removed it, nothing from the system. L3301
 

whitetiger

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Kubota tech..BX2370, RCK60, B7100HST, RTV900 w plow, Ford 1100 FWA
Nov 20, 2011
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1,102
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Kansas City, KS
HST or gear?

I read somewhere (here I think) that the hydraulic filter is pressured in a way that the system won't be open to it when not running. (Forget the actual term)

When I replaced mine not long ago, there was very little fluid lost - just a small bit that came out of the filter when I removed it, nothing from the system. L3301
The HST filter mounted on the LH side of the tractor is pressure fed so there is only the fluid in the filter plus a couple of ounces lost. It has an o-ring seal as it is high pressure and when screwed on has metal to metal contact so it is hard to get broke loose. The paint has nothing to do with it being tight.

The Hydraulic suction filter mounted on the RH side is partly gravity-fed and can lose several gallons when removed.
 

SAR Tracker

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LX2610HSDC, FEL, LX2963 Snowblower, BH77 Backhoe, forks
Nov 17, 2020
201
298
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Central Oregon
If a person had a CLEAN container to catch the hydraulic fluid, could they just pour the (still clean) hydraulic fluid back into the system after changing the filter? Assuming the fluid wasn't due to be changed anyway.
 

UpNorthMI

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L3200, L3901, MX5800, SVL75-2, KX040
May 12, 2020
850
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Up North, MI
If a person had a CLEAN container to catch the hydraulic fluid, could they just pour the (still clean) hydraulic fluid back into the system after changing the filter? Assuming the fluid wasn't due to be changed anyway.
You can certainly catch and reuse the fluid, assuming the fluid is not due to be changed.

Another method I use on my HST tractors is to put two car repair ramps on one side of the tractor so the tractor is at an angle. I do this for both the left hand side and right side filter, I found this leads to very little fluid loss.
 

Justasquid

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Equipment
L4240HSTC
Nov 2, 2020
96
44
18
Michigan
If a person had a CLEAN container to catch the hydraulic fluid, could they just pour the (still clean) hydraulic fluid back into the system after changing the filter? Assuming the fluid wasn't due to be changed anyway.
Maybe if you have 2 catch pans. The 1st catch pan to remove the filter, then slide a new pan to catch the remaining fluid that comes from the tractor. The reason I would want 2 pans is the fluid that comes back out from the filter during removal will have a lot of the small particles that have been stopped by the filter, but are still “loose” in the fluid. Generally if you see any particles in the catch pan, it’s from the filter.

You would also need to be aware of dirt falling into the pan as well. having said that, I always replace with new fluid. I’m too chicken to reuse the fluid. 😀
 

greg86z28

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Equipment
B2601
May 17, 2020
306
177
43
South Central Wisconsin
On the top of the tractor there is a breather tube. If you plug that you will slow the rate (possibly stop) at which fluid comes out. I did this on my B2601 and it worked really well. I lost very little fluid, maybe a 1/4 quart between the trans and suction filters, which might mostly be attributed to the fluid that was in the filters or in the line near the filter mount.

I saw this recommendation on this forum, I will try to find the user to give credit where it is due. The video was about testing and increasing hydraulic pressure on an L series tractor to improve lift capacity. In that video he made a comment about plugging that line to stop flow. Good idea.

greg