Help, please. My check valve keeps failing

I have a 1984 Mondial, US model. When I bought the car, it had a bad front check valve, which I replaced together with all the associated hoses with new ones.

I drove the car for about a week, 100 miles, with no problem. Today it was very hot here in California and when I started the engine in the afternoon, smoke started coming out of the engine compartment.

The new hose was melting. I touched it and it was very hot. See the picture below, how the inner part of the hose is boiling out.

I had the recirculation valve disconnected at the time (the white one that sends the exhausts fumes back to the air filter), the vacume tube was not connected, so there was no exhaust going through it. At least I saved that white valve.

I'll take the check valve back to the shop I bought it and replace it together with the melted hose.

But my question now is: why is that particular valve failing? It is the same one the failed to the previous owner. (I had the car for about 1 month, 300 miles). Can it be just bad luck? Coincidence? Is there something else going on in the front bank that is causing the valve to fail? The car was not driven before. Can it be that some debris got loose and left the valve open? Hot air ruined something inside the valve?

Murphy's law says that the front one will fail, the difficult one to remove. Not the rear, which is in plain view.

Any input is greatly appreciated.

Thanks,
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That is what I have on there now. I'll change it again.

 

It can't be the hose, as the one in the rear bank is perfect. I replaced both valves together with all the hoses. The hose in the rear is still new and flexible, the one in the front bank is hard from all the hot exhaust fumes.

The funny thing is that now the front valve appears to be working fine. The noise is gone.

The burning of the hose happened yesterday, it was a very hot day here. For some reason, the water and oil temperature gauges were very hot, slightly above the middle mark in both gauges. Today, it is also hot, but the gauges remained below the lower mark and the noise disappeared all of the sudden. I'll take the valve out and inspect it.

I saw some posts about catallytic converters getting hot and the slow down light lighting up. Should I go down that route?

Thanks for your help, Steve.