Farmall M drum brakes

I"ve had sloppy brakes, on my "51 M, with both sides being saturated with oil. Last year, I took them apart (just the bands) and tried to clean them up. The are again saturated with oil. I"m hoping some here can help. I"ve done a search and haven"t quite found the correct terms...
I pulled the band covers off of both sides leaving the band in the covers. Took the single bolt off of the middle of the "drum" and slid it out. When I look in the tractor brake housing, I can see the bearing that the drum shaft slides through. On this side of the bearing (closest to me) there is a seal. It appears to be double lipped with a spring in it, that the drum shaft also slides through. I have not pulled them out yet but on one side I can see the spring hanging down slightly. One of the drum shafts is grooved. I assume from wear. The other side is smooth. When trying to find this "seal" in the YT parts I find nothing. When looking on the internet I find references to a "brake seal" and a "bull pinion" seal.
Sorry for the long explanation but I figured more detail is better than less. I"m trying to be as specific as possible, to lessen any misunderstanding.
1. What is what I am looking to replace properly called, please?
2. What is the best way to get that old seal out and to put the new one in?

Thanks for your anticipated help!

It's called a bull pinion seal and it can be had through your local NAPA. Not sure of the part number for an M, but the original can be cross referenced. If they are the original, be aware they will fight you tooth and nail. Also the originals are considerablely thicker, but the news seal up just fine. It will also allow you to position the seal at a different location on the drum (a non-worn spot) for a better seal. Replaced them on my H a year ago and no leaks.

a slide hammer and a screw will pull the old seal out, you can also try and collapse the seal a little with a small chisel and pry it out. do not attemp to remove the housing that the seal fits in. the bull gear on the inside must be removed before that housing comes off. the new seals are thinner than the original, so you can move it in or out a little so it doesnt run in the groove, or double up the seals and pack grease between the seals.

The seal you need is measuring 95-72-10 (mm)
NBR seal will do just fine.Around 7 Bucks.No need for expensive IH seal which comes out same factory from Tokseal or NAK brand.This is also for the rearaxle seals.(95-70-10 btw)

Don't forget to put some liquid seal behind the thick reatainer since I noticed last time some oil was coming along the splines and the brake band was poluted with oil after a short time on my MV.

To explain what you are seeing is most likely the original seal that had 3 leather seals spring loaded within a steel stamped case,the old seals are no longer made & the replacements are single lip newer design neoprene rubber. You can install 1 to 3 new seals, usually 2 will suffice. The new seal is demensionally narrower than old but bore & outside are same.

I've got made in the U.S.A., National (Timken) #417344, crosses to the old part number 45073D. The National Seal has a double lip with the spring reinforcement.

Thanks for everyone's reply. Very helpful and informative.

Rusty, are those Nationals you mentioned, listed on your site, the same width as the originals? I'm measuring the originals at about 3/4" where some of the others out there are 3/8". I'm assuming this is why some have suggested putting 2 in each side. Also, what is the best way to set the new ones in there straight and square. "very carefully" I assume is the best answer...

to reinstall seals, I have a couple of 6" pieces of different diameter ABS pipe. 3", 2 1/2", etc. Make sure that the cut on the end is square. They work slick for driving large seals on. Used them on the H and the F-12, works great.