I need to replace my o-rings in my seac asso 75. Looking for information on how to do it and o-ring sizes please! I've had the gun for about a year and never used(tried to) it until today. It had no pressure! I'm assuming it's because it was in my motorhome (not being used) and 100°+ temps ruined the o-rings because when I tried to pump it up, the air would just leak out. Any info/sites would be greatly appreciated!