Vacuum pump

Check TCDS E-252 Note 3 for your C-90-16F - your vac pump replacement is just a maintenance item with log book entry only. Suggest you consider another IA if he isn't more experienced than indicated. If a field approval was submitted to the FSDO, they may call him to discuss - why!!
PS I just see Matts entry below - I think he'll probably agree - that's what the IAs are paid the big $$$$ for!

The words "vacuum" and "pump" do not occur anywhere together in the type certificate. My IA said the pump was considered an accessory. I don't understand the significance of that other than he said it's also need a field approval.

What does the type certificate for the engine say ?

A-787 for the Alon refers to the C90-16F engine but has no reference to a vacuum pump in any of the required specifications. In that case I would defer back to what is allowed on the engine as an accessory as either a direct replacement or as a PMA. That would not require a 337 field approval. (disclaimer-I'm not an A&P but have been doing research for various replacement parts on my Alon).

My vacuum pump failed. The closest replacement I can find is a RAPCO part number RAP215CC-9. It's certified for the C90-16F, but not for the A-787 Type aircraft. Does anybody know of an already STCed vacuum pump replacement. I'd rather not get a field approval if I don't have to.

-Jason