Hydraulic controller turn off delay
the retarder effect of a capacitor is not exactly, you need a retarder circuit it, will be adjustable and you can use a  555(monostable) circuit , also you have to be aware of the limits(Amperes and potence) of the 555 you will buy, not all the chip's have equals limits
i hope it will help you.

http://www.ohmslawcalculator.com/555-monostable-calculator