The two field trials revealed that the amount and type of varnish deposits in the lubrication system had a bearing on how quickly the fluid could be rid of the varnish material and for how long after the clean-up it would remain free of elevated varnish levels. There are also variables other than the level of deposits, such as the type of the varnish material, temperature, duty cycle, fluid type, state of the deposits, etc., that influence the rate of varnish removal from the fluid and the dissolution of the deposits back into the fluid.