I tried snugging up the screws and cleaning the ring terminal contact surfaces on the capacitors, but I am still geting a difference of over 10 volts between the + and - supplies at the capacitor terminals during power down as they discharge. The puttering sound did appear get a little better, but did not go away completely.
Could the drainage rate difference be due to the 13,500 ufd capacitors getting leaky due to age? If so what is the safest method of testing them outside of the circuit to verify they need to be replaced.
Any other suggestions to determine the cause for difference in drain rates between the supplies?
Thanks for the help,