Cab jack leaking

The pump is leaking out of this area not even using it or the air over hydraulic. Has anyone ever pulled this apart and replaced the seal? Wondering what it involves?

Yes you should be able to replace the pump seals. I think those pumps are made by Power packer.

Looks like MME has a seal kit for it. The manufacturer page is not much help except for a couple of kits that cost more than the whole unit, but if you want an easy button go to their website or just take it apart and match up the seals

Ron mentioned it’s a power packer. What’s the model number of the unit?
The MME kit looks like 2 orings and a cup ring.

HP5003-4204

Sean has a video on his channel of repairing one - it's very simple. Just an o-ring or quad-ring or something from a generic assortment fixed it up.

Just a note, there are other pump version out there that don't have the hex on the top. You have to disassemble from the bottom with a cir-clip. Like this one:

Ok, so I broke down and paid the $38.99 plus there crazy shipping costs from MME.
Of course for that cost you get the cheapest o-rings possible and while rolling the larger oring over the threads it broke!
So I took dimensions and figured out what you need if you want to source your own high quality orings for way less $.

Old o-rings to the left new o-rings and rod wiper seal to the right.
At the top is the rod wiper seal, deeper in is the smaller oring.
At the base of the threads is the larger oring. That’s the one that broke.