Ressurrecting a Wards Airline Tube amp and noticed a 40 mfd Electrolytic cap leaking
It looks to be a filter cap as its rated for 400vdc > I have two 22mfd rated at 450vdc
can I gang the two together to replace it?
It really depends on exactly what the cap is doing. In some filtering applications, a couple of microfarads extra won't make much of a difference, but in others it will. A schematic of the amp would be helpful.
Anyway, if you figure out that it is okay, you should be able to connect the capacitors in parallel to double the capacitance. You may need an extra board to make them fit, though.
If the caps you are putting in have been laying around for several years it is a good idea to reform the electrolytic cap gradually before putting it in the circuit. You can put about a 10k resistor in series with the cap and connect it to operating voltage.