Found a pinhole leak in my system which was installed in the late 80s. Uses a pair of web connected rubber tubes shown in this picture.

https://i.imgur.com/nRFYQSz.png

What is the right way to splice this tubing? After 30 years how much more life can I expect from this tubing? It is still pliable.

WoW...hope this isn't the start of lots of leaks for you....

I would double check what the system pressure is set at.

To fix it I would mimic what they did on the original connections and just cut out the bad section, insert a some new tubing with the fittings.

I have never seen this type of tubing...

Wishing you luck...

This looks like BioEnergy SolarRoll rubber tubing (maybe EPDM) that was often used for solar collectors back in the 1980s:

https://www.motherearthnews.com/renewable-energy/solar-heater-zmaz80mjzraw

Some folks also used this product for hydronic radiant heating systems back then too, but I have zero experience with that application of this product. There were also other rubber tube products used back then for hydronic radiant systems like Heatway, Entran and Onix that had a checkered performance history with various lawsuits because of many failures. As Newbostonconst suggested, don’t over pressurize it. You only need enough system pressure to keep the pump from cavitating which is typically just something above 10 PSI. Monitor the pressure to ascertain if you have leakage happening that isn’t visible.