The valve in the 1400 only has 1 small o-ring on the check valve, and larger thin one between the valve body halves. The exhaust valve has whats called a quad seal. Its a flat ring seal with a slight groove in it. The quad seal is inside the exhaust valve cap, and seals around the valve nipple. Theres also a cup seal on the pump rod.
Are you sure the seals are the problem? If the sear isn't holding the valve cap closed the gun won't pump up. Check to be sure its adjusted right and isn't worn. Also, if the trigger spring is bent or weak, the sear may not engage.
If you aren't sure how to proceed with repairs on this gun, you may want to call here:
http://www.airgunshop.net/index.htmlRicks prices are about the best around, and his work is top notch. He's been doing Crosman repairs for almost 30 years. Also, he won't keep you waiting for months like some other well known places. Usually turn around is a couple weeks at most. The last gun I sent for a reseal cost $30 including shipping, and was back in 10 days.