So I was contemplating putting on an oil cooler and I was thinking, when you drain the oil, what happens to the oil in the oil cooler? Does a lot of the oil drain out enough to damage valves in the oil cooling lines? Reason I ask is when I started my car after doing an oil change, the pressure gauge did not rise right away due to the oil filter being new and empty of oil (the cooler is not installed right now). Now what happens when you have an oil cooler with a lot of extra lines and with the front of the car lifted, then some of the oil would drain back empty in the cooling lines that you added to the oil cooler? Then of course when you start the engine, instead of the oil filter being the only thing to fillup, the cooling lines would also need to be filled up as well, right?

 

No worrys ---Just let it idle for a sec til u reach press----No Harm will be done.