Still trying to find a good online source for hydraulic seals and parts. Seems the ones I can find don't provide enough tech info to even buy from them, or have enough listed selection.
https://baumhydraulics.com/# HeavyEquipmentForums
Another good one is Hercules. > https://www.herculesus.com/
www.alleghenyyork.com
I ended up ordering from hydrapak. I am learning some things about seal suppliers. Seems they like to deviate from OEM part numbers so no one can figure things out. I had a local company do a quote and I walked after seeing a backup ring on the quote for $35. I paid $6 from hydrapak! This is why I am trying to find good online resources so I can see and measure, not rely on what someone puts in a quote. The quotes varied wildly and the locals were $100 higher, and no one wants to tell you what brand of seals you are buying unless you request a certain brand. So far it would seem Hercules, SKF, and Parker are probably a safe bet. As far as Cat though, I cannot recall the name, but there is a supplier I used that ONLY does Cat stuff. Very high quality and they even go so far as to run the yellow Orings with part numbers just like Cat. I am sure there is inflation but they are very good. However, for reference, I rebuilt some brakes in an excavator and that company wanted $25 per friction plate! I somehow found the direct supplier for Cat and bought them for $6 each. I needed a LOT of them. This is why I try to document suppliers when I can. I was using Grizzly for general seals but I felt their quote was high this round, and I was right.