Hyd oil filter not sealing tight

F2036

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Jan 25, 2014
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Bondurant Ia
I changed the transmission/rear end hyd filter on my BX 1850. It wants to seep a little bit of oil, so I tried another new Kubota filter and it does the same thing, drip, drip. It doesn't seem to matter how much I tighten the filter, it still drips.
Both of the filters are new and looked like they should, the surface on the rear end part is smooth and looks good also.

What am I missing??? any ideas or suggestions would be appreciated.
 
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DustyRusty

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Did you lube the sealing ring before installation. The filter only gets hand tightened with a lubed rubber ring. You need a filter wrench to get it off next time. My bet is that you have not lubed the rubber ring, and that when it contacted the metal facing, it stuck tight, and pulled the ring from the filter leaving you with a dripping oil filter. If that is the case, then just buy a new filter and lube the ring, put it on hand tight, and it will seal properly.
 

GeoHorn

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Presuming the machined surface of your tranny-case is good (as you mentioned) there are two main reasons spin-on filters fail to seal properly:

1: Gasket failure due to improper lubrication.
Many filter mfr’s instruct to lubricate the gasket with oil, usually the same oil/fluid the filter is designed to cleanse. This is a mistake for two reasons. (I know...it’s blaspheme for some guy on the internet to contradict the filter mfr’r who ought to know better than to contradict the people who MAKE the damn thing!).
But the problem(as I see it) is the instructions fail to explain WHY the want grease/oil/etc smeared on the gasket. Many owners mistakenly believe it’s to help seal the interface. While that’s true, it’s only in an indirect manner.
The reason they want you to smear grease/oil/whatever onto the gasket is to provide lubrication so that the gasket will not dislodge from the crimped-on base which holds that gasket. The problem with using oil/etc is that stuff doesn’t provide the slipperiness necessary to keep that gasket in-place...AND... heat from operating the machinery then cooks/carbonizes that old oil or grease (whatever) and not only makes it difficult as hell to remove that filter next time. The gasket is dislodged and leaks in the meantime.

2: Gasket failure due to over-torqueing of the filter which distorts the gasket. If an installer believes that a little-torque is good... he might mistakenly believe that a LOT of torque must be better!
Wrong! Too much torque simply flattens and/or pushes the gasket out-of-place and when it leaks...the disappointed owner tightens it even MORE.

I suggest you use a silicone-grease product (Dow-Corning DC4 is a good one, available from NAPA) and only tighten that filter down to about 20 INCH-pounds (or if you don’t have a method to measure that, tighten the filter to the point it bottoms and then only a 1/2 to 1 full turn further. NO MORE.
The spin on filters do not have a high-pressure area where the gasket lives. That area is actually a return-area for oil and is relatively low-pressure (less than 50 psi typical.)

Now this presumes your tractor is not overpresurrizing and has a good, smooth mounting surface.

Hope this helps.
 

200mph

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Perhaps the threaded mounting nipple is bent.

Therefore the filter is sitting flush with the mating surface.
 
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SidecarFlip

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..or the threaded nipple that secures the filter to the casting backed out when you removed the old filter and is now hitting the internal bulkhead in the new filter and not allowing it to seat fully. That threaded mounting nipple is screwed into the casting on the unit and can unscrew with the filter. It happens, I'd check to insure it's bottomed out.
 

North Idaho Wolfman

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Make sure the original filter gasket is not still stuck to the engine block.
I really hope he's not putting a hydraulic oil filter on the engine! :p

Yea I got your point, make sure the old gasket is not stuck on the old mating surface, and that is good advice!
 

SidecarFlip

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I really hope he's not putting a hydraulic oil filter on the engine! :p

Yea I got your point, make sure the old gasket is not stuck on the old mating surface, and that is good advice!
I considered that but didn't mention it. I presume the OP can differentiate between an engine oil filter and the hydraulic filter, but then maybe not....:confused:
 

F2036

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Jan 25, 2014
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Bondurant Ia
I appreciate all the replies to my question.
Yes, old gasket came off with the old filter, I already changed the engine oil, besides the hydro filter is to big to fit on the engine, so I didn't get them mixed up :)
The old filter did not leak. I'm thinking that that I'm probably tightening the filter too much. I will try some silicone grease and only use two fingers and a thumb to tighen the filter and see what happens. :) :) I'll let you fellas know how it works out.
 

200mph

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I will try some silicone grease and only use two fingers and a thumb to tighen the filter and see what happens. :) :) I'll let you fellas know how it works out.
A couple of weeks have past. Do you have an update you care to share?
 

Magicman

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Thanks GeoHorn. That left this topic unanswered even after many members offered suggestions and ideas. :rolleyes: