Ok this is the 3rd hydro this has happened on in the last 5 years. But on this job we have a much better timeline as to when it happened. We are finding purple grainuals in the oil tank that are about twice the size of coffee grounds and will clog up the intake screens enough to starve the car for oil. We had a Dover relay controller (dry unit) with a bad I2 valve. The tank was pumped down and cleaned out. We replaced the valve established working pressure with weights set bypass.And then proceeded to run the car up to temperature to make sure all adjustment held. After about 3 hours of run time the unit started starving for oil. We pumped it back down and the tank was full of the purple grainuals we had seen before!!!! Mind you we pumped the veg oil out of the tank and right back in without adding any outside oil except for what may have been in the filter pump.Back in the day when these units were converted to Vegetable oil I know they would just pump the tank down and fill them up. No draining of oil lines or emptying of the jack. Any ideas what could be our problem here????
