It is not a great process, basically it involves starting the entire cycle over.
The general rule is under 20 min abort and insert new capsule.
*You can be cheap pull the capsule from the bottom push the plunger down carefully and then add self cure acrylic, push the mass of acrylic to top of capsule so you don't trap air in the funnel, its mainly to add pressure not volume to the denture. If you are fast and efficient this will work if you are slow then your denture is setting while not under the pressure.* depending on the stock of capsules is what method I choose. If you have a major fast leak then you may want to consider opening the pulling the acrylic dough out then figuring out the problem. Likely you got chunk of stone holding you open.
Over 20 min you ignore and cross your fingers. If it comes out like crap you have to rebase denture.
I have marked my ivobase piston with 4 or 5 marks basically when there was a complete failure I opened the door and drew horizontal lines on the fully exented piston so I can tell when I am getting close. Ivobase unlike ivocap is a hybrid cold/hot cure. So it will set on its own, If I see loss of acrylic that is too fast that it will not make it to polymerization I would decide if I needed to pull early. Once you make it to polymerization there is no turning back, and likely you are good if you make it there.