Allis Chalmers oil filter

[Fixingfarmer]

Here are a couple pictures from IH/Farmall manuals I found online showing the orifice to be at the outlet. A bypass filter with an outlet orifice (restriction) like these will not affect oil pressure depending on the filter media as will be seen with a bypass filter having metered (restricted) inlet, like the AC has. From the cut away of the oil filter housing it appears the oil return is through the small hole at the lower (threaded) end of the retaining bolt.

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Yes that is what I thought I remembered and it is true like they say on the farmall you could pull the can off pull the filter throw the can back on and still probably have decent pressure.

So really the hole for the ac feeding the filter must be larger then. The filter itself then has to be the tightest restriction if a change in pressure was noticed.

 

[Jim.ME]

Yes that is what I thought I remembered and it is true like they say on the farmall you could pull the can off pull the filter throw the can back on and still probably have decent pressure.

So really the hole for the ac feeding the filter must be larger then. The filter itself then has to be the tightest restriction if a change in pressure was noticed.

The metering hole in the tube the AC filter slides down over is about 1/8", if I remember right. The return to the base is a slot about 3/8" x 1-1/2", so it can return way more oil to the base than is supplied by the orifice in the tube. Thus, the filter media does affect oil pressure.