Trans Filter started leaking

[rainman]

OK gurus , help this novice out here. I have a m 25r Allison transmission. { mounted to a 8v 71 ) out of nowhere oil started pouring out of the filter cartridge housing. Easy fix I thought , new filter and new gasket . yes I did remove the old gasket. Cleaned everything well. No burs around can , very smooth. Pressure spring nut is tight. Also cleaned the screen that is mounted near the filter. New oil of course.
Started engine and same problem exist. I've never had problems changing cartridge style filters but the problem started before I changed it , and the leak is the same and same location. Blockage somewhere maybe ? Any suggestions ?
Thank you

 

[Ski in NC]

There are two types of seals for these: A flat paper gasket and a square section rubber gasket. Only one of the two is used, and which depends on type of filter head you have. Use the wrong gasket and it will leak. I think most use the flat paper. Both should be provided with the new element.

 

[rainman]

Yes sir , the 1138 Napa did come with both. Mine does use the flat paper style, I discarded the rubber one.

 

[rainman]

OK , problem solved. Took filter back off, had a look around, didn't find anything . Reinstall filter , no leaks.
Maybe just the magic of trawler forum.

 

[Ski in NC]

Keep an eye on gear oil pressure. If regulator gets sticky pressure can go sky high and force a leak somewhere. Should be around 130-150psi.

Also the bolt that holds the can on, make sure the threads on it and in the can are in good shape.

 

[rainman]

Thanks ski in NC, good to know on the pressure .

 

[twistedtree]

I have heard that some gears have the oil filter on the high pressure supply side of the system, where others (like mine) have it on the low-pressure return side. For gears with the filter on the high pressure side I know people who have reported failures of after-market oil filters vs gear manufacturer filters - in this case ZF.

So you might want to check the manual for your gear and see what the oil flow schematic looks like, and whether you filter is on the high or low pressure side of things.

 

[rainman]

Good advice , mine is on the high pressure side . I think the bolt must have worked loose , not sure what I did , but the second time I put it on it was right. That's how I get good at doing things , do it twice.