OK so for future reference:
* Typhon V2 had tiny tiny stock washers, polished metal, one was the wrong side of the piston (guess which one broke...).
* Talion V3 had washers as big as could be (they were very close to the piston holes), dark metal, one was again on the wrong side.
* I put large washers (3mm inner hole, same external diameter as the stock Talion ones, so as large as possible) on both sides of all pistons, removed the tiny ones on the Typhon and will update this post if things break