My “CAT TRAX >>>> FLORIDA SAILCRAFT FT. LAUDERDALE FLA.” brand wheels are losing air. I’m having trouble finding the leak.
I immersed them in the pool one wheel at a time but no bubbles show up. A few hours later the tire is softer. They seem to be an older style since I bought them new in 1981.

On the side of each wheel it says “MAX INFLATION 65 IN.” OUTSIDE CIRCUMFERENCE” and has a basket ball type filler valve. The circumference measures 66 inches even when they are soft. Tread is still good but there is some age crazing around one of the filler ports on one tire and some cracking on the inside wall of the other tire.

My questions are. Is there a tube or bladder inside the tire that can be repaired? And what is the configuration of the tire internally?

I know it sounds like time for a new set of wheels but they are only 24 years old and have only been around many beaches many times.

Terry