yeah, i did with mine in the 40. i hooked up a rubber hose to one connection with a pipe nipple with a tee in the end of the hose i put a 0-15lb gage on a port of the tee and a ball valve on the other port. i took my garden hose and made it to fit the other connection on the core open the ball valve and slowly supply water to the core at 5 psi and when all the air stops coming out close the ball vavle and slowly pressurized the core to 5psi and turn off water supply. if its still holding pressure 15 minutes later and the core is still dry then it doesnt leak. if its sitting in the sun while your doing this the presuure will rise
